Magnesia Cupels

Description of Magnesia Cupels & Magnesia Cupel Blocks

Cupellation is a refining process in metallurgy, where ores or alloyed metals are treated under very high temperatures and have controlled operations to separate noble metals, like gold and silver, from base metals like lead, copper, zinc, arsenic, antimony or bismuth, present in the ore. The process is based on the principle that precious metals do not oxidise or react chemically, unlike the base metals; so when they are heated at high temperatures, the precious metals remain apart and the others react forming slags or other compounds.

High quality magnesite is the majoritary component of magnesia cupels and cupel blocks which offer below advantages:

● Great mechanical strength which is not affected by atmospheric conditions (not hygroscopic);

● The prill or bead does not adhere to the fire assay cupel surface;

● The assay will have a reduced tendency to freeze;

● No cracking or spiting, and the beads do not attach to the fire assay cupel surface;

● Quickly absorb great amounts of litharge without cracking or pitting;

● Reduce the cupellation temperature and time, resulting in minimal losses, higher accuracy and better yields.

Magnesia cupels swiftly absorb 70% of their weight in litharge (PbO) at 980℃ wihtout leaking.

Specification of Magnesia Cupels

Magnesia cupels 1, 2X, 3, 4, 5 and 6 application is to analyse gold and silver alloys. In this case, it is first necessary to wrap the sample and silver inquarts with assay lead foil or with assay lead tablets. Cupels 1 and 2X are specially suitable for silver analysis and microcupellation. On the other hand, cupels 3, 4, 5 and 6 are for the analysis of bullion, white gold, and yellow alloys.

Magnesia cupels ranging from #7A to #12 use is to analyse ores, ashes, sweeps, scraps, concentrates or electrolytic slimes.

Magnesia cupels 14, 15 and PC are production cupels. They are particularly useful, if the user does not wish to invest in a gold refinery but needs to accasionally produce gold & silver.

Specification of Magnesia Cupel Blocks

The absorption capacity of the magnesia bullion is about 8g of litharge (PbO) per hole. The magnesia bullion blocks are particularly useful when the samples have similar gold contents because they have below properties:

● Fully exploit fire assay's parallel processing capabilities;

● Fully scale to mass analysis production stage;

● Use the same block for samples, duplicates, standards & blanks;

● High accuracy–samples undergo equal ambient conditions;

● Save time–reduce manipulation hazards;

● Better stability thanks to their larger base;

● Reduce misplacing errors as assays keep the original array;

● Ideal for mass analysis of same carat alloy samples;

● Handling several bevelled blocks at one time;

● Possible to combine the use of bullion blocks with parting and annealing baskets so as to save time and nitric acid.

Applications and Related Industries for Magnesia Cupels & Magnesia Cupel Blocks

● Precious Metal Analysis

● Mining Laboratory

● Laboratory Testing

● Mineral Assaying

● Fire Assaying

● Gold Assaying