Fire Assay Small Crucibles For Gold Melting
Precious metal items of art or jewelry are frequently hallmarked (depending upon the requirements of the laws of either the place of manufacture or the place of import). Where required to be hallmarked, semi-finished precious metal items of art or jewelry pass through the official testing channels where they are analyzed or assayed for precious metal content. While different nations permit a variety of legally acceptable finenesses, the assayer is actually testing to determine that the fineness of the product conforms with the statement or claim of fineness that the maker has claimed (usually by stamping a number such as 750 for 18k gold) on the item. In the past the assay was conducted by using the touchstone method but currently (most often) it is done using X-ray fluorescence (XRF). XRF is used because this method is more exacting than the touchstone test. The most exact method of assay is known as fire assay or cupellation. This method is better suited for the assay of bullion and gold stocks rather than works of art or jewelry because it is a completely destructive method.
Fire assay small crucibles for Gold Melting
1. Long lasting,can be used many times;
2. Can withstand extremely corrosive fire assay environments;
3.Can withstand repetitive thermal shocks from 1300 degree celcius to room temperature .
|L.O.l(loss on ignition)
Top diameter 85mm;Bottom diameter 55mm;High 120mm.
1. Refractoriness:1650 centigrade degrees;
2. Refractoriness under load:1420 centigrade degrees;
3. We can supply kinds of fire assay crucibles export level,customize was acceptable, samples and performance requirement.