火试金粘土坩埚

FIRE ASSAY CRUCIBLES

Sigma supplies high-quality multi-trip clay crucibles for the analysis of precious metals using the fire assay method. Our robust crucibles are made from superior ceramic materials made to withstand extreme temperatures and have the ability to suit a wide range of matrices encountered in . A wide variety of crucible sizes are available to fit your laboratory’s testing needs. Increase your productivity and reduce operational costs with these quality yet cost-effective crucibles.

With over 40 years’ experience in the ceramic industry, we offer unsurpassed expertise and service. Consultation is available upon request.

Over 40 years experience in the ceramic industry
Capacity to suit any size of commercial laboratory
Custom sizes available
Prompt shipment
Common crucible sizes:
30g
40g
50g
45T/55g
65g
75g
Other crucible types:
The minerals industry uses a wide variety of crucible types. These include:

Silicon Carbide
Graphite
Platinum
Porcelain
Sigma’s network is at our disposal to source these other types of crucible on request.

What are fire assay crucibles?
This relatively simple looking ceramic (we call them pots) made of fire clay and proprietary additives, has an extremely long history in the gold business. Its use is referenced in historical texts that are more than 3000 years old, which when you think about it, is no surprise really. A crucible is, in simple terms, a ceramic cup.

A modern fire assay crucible is not that far removed from those of the past with the exception of the additional science behind it’s composition. Modern crucibles are made for laboratory use rather than refining and so are required to be exacting in their specifications. Additionally they should be strong enough to withstand huge changes in temperature through multiple uses.

The crucible is used for the first part of the fire assay fusion process. The following process is typical:

Flux and sample are added to the crucible
The above additions are mixed together inside
Heat is applied to the crucible and mixture by placing the pot in a furnace at > 1000oC
After a pre-determined period of time the crucible is removed and the molten contents are poured into a cast iron mould
The crucible is cooled and ready for it’s next use however, it may be disposed of if the previous sample contained high quantities of gold.
Finding Your Perfect Crucible
Fire assay can be considered the most reliable method for determining the content of precious metals — such as gold, silver, or platinum — in ores. When you’re making use of the fire assay process, a critical piece of equipment is your crucible. Let the family-owned business, Sigma, take care of your fire assay needs with their range of fire assay equipment and consumables.

Although crucibles can be used in casting processes, they are the ideal candidate for processes that make use of molten metal. They are made to be non-reactive and withstand repeated exposure to extremely high temperatures. Sigma supplies crucibles composed of a proprietary blend of clay made to customer’s specific requirements. Across a wide range of sizes, these superior quality ceramic crucibles are designed to withstand extreme temperature shocks.