Zirconium Crucibles

300

25mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 10ml Capacity
Product Code
300
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 25mm

Diameter = 26mm

Nominal wall thickness 1mm

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!

Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.

Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

301

30mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 15ml Capacity
Product Code
301
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 25mm

Diameter = 30mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!

Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.

Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

302

35mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 25ml Capacity
Product Code
302
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 33mm.

Diameter = 35mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.

Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

303

38mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 30ml Capacity
Product Code
303
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 38mm.

Diameter = 38mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

304

40mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 35ml Capacity
Product Code
304
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 40mm.

Diameter = 40mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.

Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

305

45mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 40ml Capacity
Product Code
305
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 38mm.

Diameter = 45mm.

Nominal wall thickness 1mm

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

306

45mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 45ml Capacity
Product Code
306
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 39mm.

Diameter = 45mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!

Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.

Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

307

45mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 50ml Capacity
Product Code
307
Description
Laboratory Zirconium Crucible, natural finish

Dimensions - guide

Height = 40mm.

Diameter = 45mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!

Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

308

45mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 60ml Capacity
Product Code
308
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 45mm.

Diameter = 45mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

309

48mm Diameter Zirconium Crucible

« Return to Crucibles and Lids

Capacity
Brimful Capacity: 70ml Capacity
Product Code
309
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 45mm.

Diameter = 48mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!
Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature

310

51mm Diameter Zirconium Crucible

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Capacity
Brimful Capacity: 80ml Capacity
Product Code
310
Description
Laboratory Zirconium Crucible, natural finish.

Dimensions - guide

Height = 48mm.

Diameter = 51mm.

Nominal wall thickness 1mm.

Supplied in standard packs of 1.

Heating/Cooling Information
Excellent low cost replacement to platinum virtually eliminates sample contamination.

Benefit of using zirconium crucibles, they do not require platinum tipped tongs.

Zirconium crucibles are fragile! Handle carefully during unpacking, transportation, handling and cleaning.

Zirconium exhibits superb corrosion resistance in most organic and inorganic acids, salt solutions, strong alkalis and a few molten salts. An effective all round crucible for fusions employing sodium carbonate and sodium peroxide.

Heating zirconium produces a creamy white passive oxide film, corrosion barrier, stable in both reducing and oxidizing conditions.

Check before heating any crucible for any micro-cracks, replace with new zirconium crucible.

Do not over load material in zirconium crucibles, this can increase the possibility of uneven heating.

Under vacuum, argon or helium zirconium crucibles can be heated to 1450°C otherwise temperature limit for use in air is 450˚C to 500˚C.

A slow heating ramp rate and cooling rate are highly recommended to minimize the thermal shock on crucibles. When increasing the temperature, special attention should be paid on two sensitive temperature periods: not exceeding 3°C/MIN during 100°C ~300°C and 1050°C ~1200°C. The rate can be faster in other temperature ranges, but it is recommended to be less than 5°C /MIN.

DO NOT take zirconium crucibles directly out of furnace at high temperature otherwise they may crack. Recommend remove from heat when the temperature is under 100°C.

Zirconium crucibles should NOT be heated by torch or furnaces that cannot control temperature change rate. The uneven heating can cause cracks!

Features and Benefits
Why Zirconium crucibles?
It is no secret that zirconium crucibles cost more than porcelain, steel or nickel. However the average number of fusions that can be made in a zirconium crucible, as opposed to those of nickel, the ratio of longevity stands at 20 to 1. The higher cost zirconium crucible is recovered many times over.

In addition to cost effectiveness, zirconium crucibles hold several advantages over other materials in the laboratory. If compared to platinum, several distinct advantages are readily apparent.

- Ideal for most fusions done in full heat, resulting in little or no attack or oxidation of the crucible regardless material or flux mixture.

- Resistant to melts of alkali (Na, K, Li) carbonates, hydroxides, peroxides, borates, nitrates, chlorides and some fluorides, or combinations of above.

- Completely resistant to most solvents of all concentrations except hydrofluoric acid.

- Offers virtual elimination of sample contamination.

- Resistance to molten sodium peroxide.

- Will not alloy with more easily reducible metals.

- Unlike platinum no smoothing and reshaping is necessary.

- Does not have the high-cost investment and security problems of platinum.
Notes
Zirconium


Many regard Zirconium as a rare metal yet it is not uncommon but an exotic material.
Zirconium, however, has many rare, even unique, qualities such as its remarkable corrosion resistance, being used extensively in the chemical processing industry. Zirconium will withstand a range of caustics and acids to a greater degree than any other commonly used metal and stands in a class by itself.



Cleaning Zirconium crucibles


Hydrofluoric acid is the only cleaning agent that should not be used to clean zirconium crucibles.



Applications for Zirconium Crucibles


Zirconium crucibles are suitable for several applications in the analytical chemistry.


  • Sodium Peroxide Fusions - used with refractory or high-silica materials such as chromate, magnetite, ilmenite, retile, silicon, silicon carbide, and certain alloys and steels. An excellent general flux for almost any material.

  • Sodium Carbonate Fusions - decomposes most silicates of aluminium, calcium, chromium, nickel; also halides of silver; and sulphates of barium and lead.

  • Lithium Salt Fusions - flux for oxide and silicate materials when sodium and potassium need to be determined or when large amounts of sodium would interfere with x-ray fluorescence or atomic absorption procedures.



Fusions in Zirconium Crucibles



Fusions are best where there is little or no attack or oxidation of the crucible - regardless of the sample material or flux mixture.


In making fusions, the sample is mixed with 4 to 10 times its weight of flux and placed over a bed of flux in the crucible and heated.

When molten it either becomes clear/homogeneous, or a very bright red, the fusion is now complete. The fused mass can be allowed to solidify in the crucible. The crucible and contents can then be placed in a beaker covered with water and the suitable solvent added to remove the fused mass from the crucible. Any material adhered to crucible can be dissolved out with more solvent.

Under these conditions only a few milligrams of zirconium will be introduced into the sample. If this trace needs removing it can be accomplished by using strong acid solutions (HCl, H2SO4).



Fluxes which can be used in Zirconium Crucibles


Listed below are fluxes that can be used to reduce melting points along with some applications that are normally troublesome.


  • Sodium Peroxide - use with refractory materials such as chromite, magnetite, ilmenite, rutile, silicon, silicon carbide, certain alloys and steels, etc., an excellent general flux for most any material. Two precautions to be taken when fusing chromite or other material high in chrome. When these materials are fused with peroxide, the chrome is oxidized to chromate which will tend to leave a yellow film on the inside of the crucible which will be unnoticed until the crucible has been removed from the subsequent dissolving operation, rinsed and dried.


This can be prevented by adding a few millilitres of hydrogen peroxide to the acid solvent (H2S04) while the crucible is still immersed. The peroxide in acid reduces chromate to chromic chrome which goes readily into solution. The excess peroxide can be eliminated by boiling. Chrome can then be determined by the usual persulfate oxidation followed by a reduction titration.


Peroxide fusions of silicon carbide and other finely pulverized metals and alloys are another matter. These materials tend to react violently at very low temperatures with oxidizing fluxes and will often burn right through iron or nickel crucibles on their first use. However, these can be safely fused in zirconium if the sample is first mixed with about 4 to 6 times its weight of powdered anhydrous sodium carbonate; (0.25gram sample is usually more than enough) then add about twice the sample weight of sodium peroxide and mix.


The crucible and contents are then gently heated until melting around the edges begins.


When the mixture appears to be melted and quiet, the temperature can be increased and fusion continued as usual.


  • Sodium Carbonate: Melting Point approximately 850°C. Decomposes most silicates of aluminium, calcium, chromium nickel, etc.; also halides of silver, and sulphates of barium and lead.


  • Potassium Carbonate: Melting Point approximately 910°C. Acts the same as sodium carbonate and can be mixed with it.


  • Sodium and Potassium Carbonate: mixture acts as either one alone but melts at a lower temperature than either one alone.


  • (Na, K) carbonates plus oxidizing agent: (KNO3, KC103, Na202, Mg0, Zn0): Used on sulphide ores of arsenic, antimony, iron, nickel, molybdenum, etc.


  • Sodium Hydroxide: Melting Point approximately 320°C. Basic flux for oxidized ores of tin, zinc, antimony, etc.


  • Potassium Hydroxide: Melting Point approximately 360°C.


  • Sodium Chloride: Melting Point approximately 800°C. Neutral flux. Can be used as a cover for fusion mixtures.


  • Potassium Nitrate: Melting Point approximately 340°C. Powerful oxidizing agent and basic flux. Used as a mixture with carbonates.


  • Sodium Nitrate: Melting Point approximately 320°C. Acts same as potassium nitrate.


  • Lithium metaborate: Melting Point approximately 840°C. Flux for various oxide and silicate materials when sodium and potassium need to be determined.


  • Lithium Carbonate: Melting Point approximately 620°C.


  • Lithium Hydroxide: Melting Point approximately 450°C. Can be added to other fluxes to help lower melting points.


  • Lithium Fluoride: Melting Point approximately 870°C. Added to (Na, K) carbonates.


  • Calcium Carbonate - Ammonium Chloride: A sintering flux used to make soluble alkalis for analysis of sodium and potassium.


  • Sodium Borate (Borax glass): Melting Point approximately 740°C. Used with (Na, K) carbonates to give a lower melting flux for refractory silicates and oxides of aluminium, iron, nickel, etc.


This list of fluxes can be used in any combination in zirconium crucibles so long as the fusions are made in the reducing flame of the gas burner or in a furnace equipped to provide an inert atmosphere such as argon or maybe helium. Nitrogen might be used if the fusion time at high temperature was relatively short, but not recommended and will embrittle zirconium after exposure for long periods of time that may shorten the useful life of the crucible.


An additional benefit can be obtained by combining two or more sodium or potassium salts (carbonates, peroxides, hydroxides); or two or more lithium salts (borates, peroxides, carbonates, hydroxides). Using this procedure, the melting temperature of the fusion can often be lowered to a temperature below that at which any of the fluxes alone would melt. This lower melting point also results in an easier-to-pour melt, a faster fusion process and an increase to the useful life of the zirconium crucible.


Zirconium crucibles and covers, and other laboratory ware are an excellent alternative to the very expensive noble metals e.g platinum and fragile glass, porcelain and quartz ware for making peroxide and similar fusions in preparing samples for chemical analysis.


While prolonged exposure to air at temperatures of more than 750°C can have a negative effect on zirconium, this can be reduced by either: using cooler reduced portion of the flame, or enveloping the crucible in an inert atmosphere.



The following have been found NOT suitable for Zirconium Crucibles


Chemical analysis of Magnesite and Dolomite refractories using Luoyang Method at 1000°C in a furnace.

No accessories available for this product.

Metalware Supplement

PDF File   Product Literature