The Collaborative International Dictionary
Cupellation \Cu`pel*la"tion\ (k[=u]`p[e^]l*l[=a]"sh[u^]n) n. The act or process of refining gold or silver, etc., in a cupel.
Note: The process consist in exposing the cupel containing the metal to be assayed or refined to a hot blast, by which the lead, copper, tin, etc., are oxidized, dissolved, and carried down into the porous cupel, leaving the unoxidizable precious metal. If lead is not already present in the alloy it must be added before cupellation.
Wiktionary
n. The assaying of precious metal in a cupel.
Wikipedia
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.
Since the Early Bronze Age, the process was used to obtain silver from smelted lead ores. By the Middle Ages and the Renaissance, cupellation was one of the most common processes for refining precious metals. By then, fire assays were used for assaying minerals, that is, testing fresh metals such as lead and recycled metals to know their purity for jewellery and coin making. Cupellation is still in use today.
Usage examples of "cupellation".
Ores of Lead -- Geographical Distribution of the Lead Industry -- Chemical and Physical Properties of Lead -- Alloys of Lead -- Compounds of Lead -- Dressing of Lead Ores -- Smelting of Lead Ores -- Smelting in the Scotch or American Ore-hearth -- Smelting in the Shaft or Blast Furnace -- Condensation of Lead Fume -- Desilverisation, or the Separation of Silver from Argentiferous Lead -- Cupellation -- The Manufacture of Lead Pipes and Sheets -- Protoxide of Lead -- Litharge and Massicot -- Red Lead or Minium -- Lead Poisoning -- Lead Substitutes -- Zinc and its Compounds -- Pumice Stone -- Drying Oils and Siccatives -- Oil of Turpentine Resin -- Classification of Mineral Pigments -- Analysis of Raw and Finished Products -- Tables -- Index.
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.
In fact, in routine assays, where the quantity as well as the quality of the gold is known within fair limits, it is often the custom to add the silver for inquartation to the lead during the first cupellation.
He proceeds by lixiviation with some particular chemicals and then by cupellation according to principles discovered by himself.
The cupellation of large quantities of alloy or of alloys which contain tin, antimony, iron, or any substance which produces a scoria, or corrodes the cupel, must be preceded by a scorification.
When the cupel shows signs of the presence of these metals in objectionable quantity, it is well to repeat the assay and scorify so as to remove them before cupellation.
Or, if the cupellation loss is neglected or calculated in some other manner, the slag or slags from the scorifier may be powdered and mixed with 20 grams of oxide of lead, 5 grams of borax, and 1 gram of charcoal.
Or, if the cupellation loss is neglected or calculated in some other manner, the slag or slags from the scorifier may be powdered and mixed with 20 grams of oxide of lead, 5 grams of borax, and 1 gram of charcoal.
These figures are based on those given by Plattner, and apply only to buttons of such shape as those left after cupellation.
Here is the list: monophysite, mephitic, calineries, diapason, grimoire, adapertile, retromingent, perllan, cupellation, adytum, sepoy, subadar, paludal, apozemical, camorra, ithyphallic, alcalde, aspergill, agathodemon, kakodemon, goetic, and opopanax.
First, when the rough ingots leave the smelt for cupellation, they are counted out by a weasel who can't actually count.
Now, regarding the ingots of pure silver which are produced at the cupellation hearth.
The smelting furnace was a perpetual roar, varied only by the fervent wheeze of bellows on the cupellation hearths.