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Also exploiting the stability of thiosulfate coordination complexes, ammonium thiosulfate is also used for leaching of gold and silver. It works with presence of copper as a catalyst. This process is a nontoxic alternative gold cyanidation. [5]
Gold cyanidation (also known as the cyanide process or the MacArthur–Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. [1]
Sodium thiosulfate and ammonium thiosulfate have been proposed as alternative lixiviants to cyanide for extraction of gold from ores [8] and printed circuit boards. [9] The complex [Au(S 2 O 3) 2] 3-is assumed to be the principal product in such extractions. Presently cyanide salts are used on a large scale for that purpose with obvious risks. [8]
Cyanide leaching "heap" at a gold mining operation near Elko, Nevada. On top of the large mounds of ore, are sprinklers dispensing a solution of cyanide. Gold extraction is the extraction of gold from dilute ores using a combination of chemical processes. Gold mining produces about 3600 tons annually, [1] and another 300 tons is produced from ...
Leaching is a process widely used in extractive metallurgy where ore is treated with chemicals to convert the valuable metals within the ore, into soluble salts while the impurity remains insoluble. These can then be washed out and processed to give the pure metal; the materials left over are commonly known as tailings .
The Pasadena facility's other products, which are sold domestically, include ammonium thiosulfate fertilizer and sulfuric acid. The facility uses ammonia and sulfur as its primary feedstocks ...
Thiosulfate (IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula S 2 O 2− 3. Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid , such as sodium thiosulfate Na 2 S 2 O 3 and ammonium thiosulfate (NH 4 ) 2 S 2 O 3 .
Macy’s responded to the investor proposal Monday, saying the company is committed to “delivering sustainable, profitable growth and driving shareholder value.”