Fire Assay Crucibles

Westref 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

Westref’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.


“Reliable, driven, family business that provides quality products and will work diligently with its partners towards mutual success.”

Anonymous customer survey submission, 2016

“I hope you can keep producing such wonderful products and expand the range of your products”

Head of Fire Assay

“We have been using Western Refractories Fire Assay Flux, Crucibles and Cupels for the past six years at our Laboratory in Metro Perth and have had virtually no issues with the quality of the products or timely supply.”

Laboratory Manager Perth, Western Australia

“WR’s level of support, commitment to partnering, response time and desire to constantly improve are exceptional.”

Procurement Lead Perth, Western Australia
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