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Jul 27, 2012· Sodium thiosulfate will leach gold (dissolve gold), in the use of sodium thiosulfate to leach ore they use air or oxygen, many times ammonia is added, many time''s copper is used as a catalyst for the reaction, keeping the pH regulated is also important for the leach to work.
Coppercatalyzed thiosulfate leaching is being investigated by the Bureau of Mines as a potentially economical and environmentally safe method for heap leaching or in situ leaching of lowgrade oxidized gold ores. Six variables were investigated in fractional factorial screening tests ...
Gold recovery by catalytic copper ammonium thiosulphate solution has been studied. Such a process strategy is very attractive for leaching certain difficulttotreat ores and presents lessened lixiviant toxicity compared to cyanide. Newmont Gold Company has evaluated the ammonium thiosulphate heap leach process for gold recovery from low grade carbonaceous sulphidic refractory ores following ...
The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals and a reference silicate gold ore. In the leaching test on the reference gold ore, about 93% of gold was extracted within hours.
PDF | Ammoniacal thiosulphate leaching of gold finds a better substitute as it is nontoxic and environmentally safe as compared to the toxic cyanide system for gold extraction. In the present ...
As part of the thiosulphate process at Goldstrike, goldbearing ore is heated as a thick slurry of ore, air, water and limestone in large pressure chambers or autoclaves and then pumped into the ...
An improved thiosulphate leach process for the recovery of gold from ores and other goldbearing materials, characterised in that the leach solution comprises thiosulphate, thiourea or a reagent chemically related thereto, and an oxidant that does not oxidise thiosulphate, the process producing a pregnant leach solution from which gold may be recovered.
Alternative lixiviants to cyanide for leaching gold ores Aylmore Placer Dome Technical Services Ltd., 323 Alexander St., Vancouver, BC, Canada V6A 1C4 Over 25 alternative lixiviant processes to cyanide have been tested in the laboratory, some of which have been successful for niche applications.
Oxidized gold ores are ... thiosulphate as lixiviant, ferric as oxidant and thiourea as a catalyst for gold oxidation might be usable for anaerobic leaching of gold ores. This work also indicated that the ... IN PLACE LEACHING OF OXIDIZED GOLD DEPOSITS 45 systems under anaerobic conditions. The oxide gold ore
Processes for recovering gold from coppergold ores thiosulfate leaching or gold ores copper catalyzed thiosulfate leaching using ion exchange technology are disclosed. The processes include subjecting the goldbearing and copperbearing thiosulfate solution to a pH and/or temperature adjustment to reduce tetrathionate concentration in the thiosulfate solution prior to contacting with an .
Gold cyanidation (also known as the cyanide process or the MacArthurForrest process) is a hydrometallurgical technique for extracting gold from lowgrade ore by converting the gold to a watersoluble coordination complex. It is the most commonly used leaching process for gold extraction.
Thiosulfate leaching offers a number of benefits related to gold recovery yields and environmental concerns: Thiosulfate leaching of gold ores has great potential to reduce the impact on the environment. Unlike cyanide, which is highly toxic, the chemicals used in the thiosulfate leaching .
Aug 02, 2019· Thiosulphate dissolves the fine gold out of ores (the gold that has not recovered by gravity) at similar rates to conventional techniques. It''s safe and lowers environmental impacts. The method has undergone intensive testing in the laboratory to understand its leaching performance in association with reagent recovery and recycle.
Apr 25, 2017· How to Leach Gold Ore With Chlorination ... The use of chlorine is both the cheapest and most plentiful method for leaching gold. When you mix sodium chloride and hydrochloric acid together, you produce a form of electrolysis that removes gold from rock and soil.
Thiosulphate leaching is a process that removes gold from gold bearing ores without the use of cyanide. Although not as aggressive a leaching agent as cyanide, thiosulphate offers several technological advantages including its lower toxicity and greater efficiency with gold deposits associated with pregrobbing ores. The thiosulphate leaching ...
A diagnostic leaching showed that partial oxidation of the sulphide minerals in a gold ore was beneficial for thiosulphate leaching of gold. A pretreatment process with oxidative ammoniacal solution enhanced the thiosulphate leaching of the sulphide ore, while the thiosulphate consumption was substantially reduced.
alternative to cyanidation for treating some sulphidic gold ores. Keywords: Thiosulphate, gold oxidation, leaching, electrochemistry, kinetics. Introduction Concern about the environmental impact of the widely used cyanidation technology has generated a lot of interest in searching for an alternative process for gold leaching over the past years.
In this article, a comprehensive review of fundamental studies of leaching of gold from different ores in ammoniafree thiosulfate solutions is presented with special emphasis on factors that ...
Jul 27, 2018· The substitution method of recovering gold from thiosulfateethylenediamine (en)Cu 2+ leaching solution using copper powder was studied. The effects of reaction time, stirring speed, pH, thiosulfate concentration, en/Cu 2+ molar ratio, Cu/Au + mass ratio, and temperature on gold
In this study, thiosulphate leaching of gold from the refractory Kaletaș ore was evaluated as an alternative to cyanide leaching. The extraction of gold in the thiosulphate leaching system was similar to that in cyanide leaching system with the highest gold extraction of % in thiosulphate medium.
Hydrometallurgy of gold 67 Thiosulphate The first reported use of thiosulphate for precious metal extraction dates back to the beginning of the century. In that method, known as Patera''s process, the ore was first roasted in a chloride atmosphere and just after a thiosulphate leaching was used to recover gold and silver (Zipperian et al. 1988).
Ammoniacal thiosulphate solution allows the solubilization of gold as stable anionic complex. Leaching of gold occurs at appreciable dissolution rates. The aim of this work is devoted to a preliminary evaluation of the feasibility of thiosulphate leaching for the extraction of gold from precious metals ores on a laboratory scale.
Thiosulfate leaching can be considered a nontoxic process, the gold dissolution rates can be faster than conventional cyanidation and, due to the decreased interference of foreign cations, high gold recoveries can be obtained from the thiosulfate leaching of complex and carbonaceoustype ores.
Thiosulfate leaching of gold from waste mobile phones Ha, Lee J.C., Jeong J., Hai, Jha Institute for Environmental Science and Technology, Hanoi University of Technology (HUT), 1 Dai Co Viet, Hanoi, Viet Nam; Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 92, Gwangno, Yuseonggu, Daejeon 305350, South Korea; Metal ...
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