from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A refining process for nonoxidizing metals, such as silver and gold, in which a metallic mixture is oxidized at high temperatures and base metals are separated by absorption into the walls of a cupel.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The assaying of precious metal in a cupel.
from the GNU version of the Collaborative International Dictionary of English
- n. The act or process of refining gold or silver, etc., in a cupel.
from The Century Dictionary and Cyclopedia
- n. Separation of gold and silver from lead by treatment in a cupeling-furnace or in a cupel.
But the satisfaction was at its height when the crucible produced, after cupellation, a button of
FIRE ASSAY* smelting with gold collector, separation, cupellation muffle or retort furnace, crucible, cupel taste (assay) lead, borax, soda, potash chemical
The appliances in connection with mining and metallurgy include a five-stamp battery, Blake crusher, automatic machine jigs, an engine pulverizer, a Root and a Sturtevant blower, with blast reverberating, wasting, cupellation, and fusion furnaces, and all other means for reducing ores.
_ When the gold is alloyed with easily oxidizable metals, such as copper or lead, it may be refined by cupellation.
To them is due the discovery of antimony, sulphuric ether and phosphorus, the cupellation of gold and silver, the determining of the properties of saltpetre and its use in gunpowder, and the discovery of the distillation of essential oils.
But the cupellation loss is smaller with less gold and greater with more copper, and it so happens in these assays that these two opposites nearly neutralise one another.
The bad effect of a higher temperature in increasing the cupellation loss need hardly be considered in the case of such small buttons of gold as are obtained in assaying gold ores, as any loss there may be is hardly appreciable by the balance.
When the gold is accompanied by a larger proportion of silver, and both have to be determined, the cupellation must be conducted exactly as in a silver assay, the usual precautions being taken to moderate the temperature so as to lessen the cupellation loss and to promote a slow and undisturbed solidification in order to avoid spirting.
~  -- The cupellation of lead for gold differs very little from that of lead carrying silver.
Silver lead alloys, cupellation of, 98 sampling of, 157
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