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The term refining is used in a narrower context. Henry Cort's original puddling process only worked where the raw material was white cast iron, rather than the grey pig iron that was the usual raw material for finery forges. To use grey pig iron, a preliminary refining process was necessary
16th century cupellation furnaces (per Agricola). Cupellation is a refining process in metallurgy in which ores or alloyed metals are treated under very high temperatures and subjected to 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.
Parting vessels used for refining gold with the cementation process have been found in London, Lincoln, York and Winchester. The London vessels, dating from the Flavian period (c. 70–85 AD), were sealed using luting clay ; XRF analysis detected gold and silver, with highest concentration around the sealed region showing possible escape of ...
The chloride process became obsolete with the development of the cyanide process. [22] [23] In 1887, John Stewart MacArthur, working in collaboration with brothers Dr Robert and Dr William Forrest for the Tennant Company in Glasgow, Scotland, developed the MacArthur-Forrest Process for the extraction of gold ores. By suspending the crushed ore ...
The Wohlwill process is an industrial-scale chemical procedure used to refine gold to the highest degree of purity (99.999%). [1] The process was invented in 1874 by Emil Wohlwill. This electrochemical process involves using a cast gold ingot, often called a doré bar, of 95%+ gold to serve as an anode.
The process was first used on the Rand in 1890 and, despite operational imperfections, led to a boom of investment as larger gold mines were opened up. [ 8 ] [ 5 ] By 1891, Nebraska pharmacist Gilbert S. Peyton had refined the process at his Mercur Mine in Utah, "the first mining plant in the United States to make a commercial success of the ...
Escalating trade tensions and concerns over the sustainability of the U.S. fiscal balance sheet could help ignite a fire under the price of gold in the coming year, according to a study by Goldman ...
The zone melting process developed by William Gardner Pfann was used to produce pure germanium, and subsequently float-zone silicon became available when Henry Theuerer of Bell Labs adapted Pfann's method to silicon. Types of materials that are usually refined: metals (see Refining (metallurgy) petroleum (see Oil refinery) silicon; sugar (see ...