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THIOSULPHATE LEACHING AN ALTERNATIVE TO

CYANIDE IN GOLD PROCESSING THIOSULPHATE LEACHING 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

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Thiosulfate leaching of gold—A review ScienceDirect

2001-2-1  The ammoniacal thiosulfate leaching process for gold and silver extraction has been reviewed in terms of leaching mechanism, thermodynamics, thiosulfate stability, and gold recovery options. The application to different ore types and process options have also been discussed.

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Thiosulfate leaching of gold—A review ScienceDirect

The thiosulfate leaching process it catalysed by copper and has several advantages over the conventional cyanidation process. Thiosulfate leaching can be considered a non-toxic 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

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Thiosulfate Leaching Process for Gold Extraction

2017-2-20  Thiosulfate leaching appears to be one of the most promising alternatives to cyanidation. Understanding gold thiosulfate leaching system plays a crucial role in order to effectively extract gold, in which the kinetics and equilibrium adsorption of thiosulfate, polythionates, gold

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Biooxidation‒thiosulfate leaching of refractory gold

2019-7-21  Ammoniacal thiosulfate was used for gold extraction from the biooxidation residue of the refractory gold concentrate. The results showed that the optimal reagent conditions were 0.18 M thiosulfate, 0.02 M copper(II), 1.0 M ammonia, and 0.24 M sulfite. Under these conditions, a maximum gold leaching efficiency of 85.05% was obtained.

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Thiosulfate leaching of gold A review 百度学术

2001-2-1  The thiosulfate leaching process it catalysed by copper and has several advantages over the conventional cyanidation process. Thiosulfate leaching can be considered a non-toxic 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

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Sodium Thiosulphate Gold Leaching

2016-6-2  Sodium Thiosulphate Gold Leaching. The gold industry has been seeking alternative reagents for leaching gold from low-grade ores for the past 25 years. The cost and transport of cyanide, the poor recovery of gold from carbonaceous ores, the lack of selectivity of cyanide towards copper minerals and the cost of waste treatment are real factors which

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Thiosulphate Stability In Gold Leaching Process

2004-11-29  Ammonium thiosulphate is an alternative gold leaching Laaviant used to replace cyanide. The current problem of thiosulphate gold leaching is the high reagent consumption, To understand the decomposition chemistry of thiosulphate, solution stability tests were conducted in open and sealed vessek mder ambient temperature

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Improvement of thiosulfate stability in gold leaching

2003-5-1  Ammonium thiosulfate is a noncyanide lixiviant for gold leaching. However, the major problem with this leaching method has been the high consumption of reagents. To leach a mild-refractory copper-bearing gold ore, the authors used a reagent combination of 0.3M (NH 4) 2 S 2 O 3, 0.03M CuSO 4 and 3M NH 3 at pH 10.2 for 24 hours.

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Cyanide alternative leaching reagents for gold recovery

2019-7-31  Thiosulfate Leaching of Flue Dust Flue dust arises in e-waste shredding processes and contains the same elements as e-waste in general but in a different allocation. The low gold concentration enables an important demonstration of the selectivity of TS [32]. Investigated parameters were among others: concentration of TS, ammonia

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Thiosulfate Leaching Process for Gold Extraction

2017-2-20  Thiosulfate leaching appears to be one of the most promising alternatives to cyanidation. Understanding gold thiosulfate leaching system plays a crucial role in order to effectively extract gold, in which the kinetics and equilibrium adsorption of thiosulfate, polythionates, gold thiosulfate

get price

Biooxidation‒thiosulfate leaching of refractory gold

2019-7-21  A process of biooxidation followed by thiosulfate leaching of gold from refractory gold concentrate was investigated. Mineralogical studies on the concentrate showed that very fine gold grains (<10 μm) were encapsulated in pyrite and arsenopyrite, while the proportion of monomer gold was only 21%. The gold-bearing sample was identified as a high-sulfur fine-sized wrapped-type refractory gold

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Thiosulfate Leaching of Gold from Copper Bearing Ores

2018-5-26  Thiourea leaching from an oxidized gold-copper ore with 90-95% gold extraction was also reported (McInnes et al., 1989). However, acid pre-leaching of soluble copper was required in order to reduce thiourea consumption to acceptable levels. Ammoniacal Thiosulfate Leaching. Ammonium thiosulfate has been used in photography for many decades.

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(PDF) A Review of Thiosulfate Leaching of Gold: Focus on

2017-6-15  Ahern, N. Thiosulfate Degradation during Gold Leaching in Ammoniacal Thiosulfate So lutions: A Focus Trithionate. Ph .D. Thesis, Univer sity of British Columbia, V anc ouv er, BC, Canada, October

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Thiosulphate Stability In Gold Leaching Process

2004-11-29  Ammonium thiosulphate is an alternative gold leaching Laaviant used to replace cyanide. The current problem of thiosulphate gold leaching is the high reagent consumption, To understand the decomposition chemistry of thiosulphate, solution stability tests were conducted in open and sealed vessek mder ambient temperature

get price

Improvement of thiosulfate stability in gold leaching

2003-5-1  Ammonium thiosulfate is a noncyanide lixiviant for gold leaching. However, the major problem with this leaching method has been the high consumption of reagents. To leach a mild-refractory copper-bearing gold ore, the authors used a reagent combination of 0.3M (NH4)2S2O3, 0.03M CuSO4 and 3M NH3 at pH 10.2 for 24 hours. In the testing, thiosulfate consumption was 30 kg/t of ore. Dissolved

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Study on oxygen pressure thiosulfate leaching of gold

2019-8-1  Thermodynamic calculations showed that the improvement of temperature and pressure was favorable to gold leaching by thiosulfate. However, high temperature and pressure also caused high thiosulfate consumption (55.3 kg/t-ore of sodium thiosulfate) and relatively low gold extraction (87.6%) without additives.

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The role of ligands and oxidants in thiosulfate leaching

2017-8-28  the thiosulfate leaching of gold has been carried out at high temperatures up to 80°C and at oxygen partial pressures up to 100 psig (19). For example, a carbonaceous ore of gold grade 9-10 Au g/t contained 81.8% of gold associated with Gold Bulletin 2005 • 38/4 171 Figure 1

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A kinetic study that compares the leaching of gold in the

This article presents a detailed kinetic study of gold leaching in cyanide, ammonia/thiosulfate, and chloride/hypochlorite solutions. The gold leach rates were measured using a rotating electrochemical quartz crystal microbalance (REQCM). This instrument allows the mass of a gold sample to be measured in situ, with a sensitivity of less than 10

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Cyanide alternative leaching reagents for gold recovery

2019-7-31  an efficient gold recovery via thiosulfate leaching requires a strict process control, which is hardly manageable when a complex input material like crushed e-waste is used. In superficial leaching ex-periments of holistic RAM’s a formation of a passive layer was observed, which hindered or slowed

get price

Thiosulfate Leaching of Gold from Copper Bearing Ores

2018-5-26  Thiourea leaching from an oxidized gold-copper ore with 90-95% gold extraction was also reported (McInnes et al., 1989). However, acid pre-leaching of soluble copper was required in order to reduce thiourea consumption to acceptable levels. Ammoniacal Thiosulfate Leaching. Ammonium thiosulfate has been used in photography for many decades.

get price

(PDF) Thiosulfate leaching of gold—A review Mark

Hemmati et al. (1989) investigated the thiosulfate leaching of gold from carbonaceous ore that contained 2.5% organic carbon. The optimum conditions for gold extraction were found to be 35°C and 103 kPa oxygen over pressure, pH 10.5, 3M NH3 with a lixiviant

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Study on oxygen pressure thiosulfate leaching of gold

2019-8-1  Thermodynamic calculations showed that the improvement of temperature and pressure was favorable to gold leaching by thiosulfate. However, high temperature and pressure also caused high thiosulfate consumption (55.3 kg/t-ore of sodium thiosulfate) and relatively low gold extraction (87.6%) without additives.

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Effect of Pyrite on Thiosulfate Leaching of Gold and the

Ammoniacal thiosulfate has been studied over the last three decades as a nontoxic and highly-efficient alternative lixiviant to cyanide for leaching gold from gold ores with copper(II) acting as a catalyst [1,2].Much of the work has concentrated on copper-gold ores, carbonaceous gold ores and complex sulfidic gold ores where the recovery of gold by cyanidation is unsatisfactory or the

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The role of ligands and oxidants in thiosulfate leaching

2017-8-28  the thiosulfate leaching of gold has been carried out at high temperatures up to 80°C and at oxygen partial pressures up to 100 psig (19). For example, a carbonaceous ore of gold grade 9-10 Au g/t contained 81.8% of gold associated with Gold Bulletin 2005 • 38/4 171 Figure 1

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© University of Science and Technology Beijing and

2021-4-27  Thiosulfate is not only cheap and non-toxic, but also can form stable gold complexes. It is also suitable for leaching typical oxidized gold ores [8]. With the leaching of certain sulfide minerals with thiosulfate, however, previous studies have shown that while a large amount of thiosulfate is consumed, only a poor leaching rate is obtained.

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Thermodynamic analysis of gold leaching by ammoniacal

2001-11-1  Thiosulfate offers a nontoxic alternative to cyanide for processing gold ores. The mechanism of leaching gold using ammoniacal thiosulfate solution is driven by the Cu(II)-Cu(I) redox couple and is complicated by competing ligands such as NH 3 and S 2 O 3 2−.It is shown that an understanding of the copper speciation and sulfur speciation is required to optimize this system.

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thiosulfate leaching Gold Refining Forum

2011-5-19  out if Thiosulfate is a viable process for extracting gold. I would like to hear the facts,from someone that has used it in a real mining situation.Bits and pieces of information are what is dangerous with any process. I have edited this to include some information that may help the forum members in the future, and one in particular.

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A kinetic study that compares the leaching of gold in the

This article presents a detailed kinetic study of gold leaching in cyanide, ammonia/thiosulfate, and chloride/hypochlorite solutions. The gold leach rates were measured using a rotating electrochemical quartz crystal microbalance (REQCM). This instrument allows the mass of a gold sample to be measured in situ, with a sensitivity of less than 10

get price

Cyanide alternative leaching reagents for gold recovery

2019-7-31  an efficient gold recovery via thiosulfate leaching requires a strict process control, which is hardly manageable when a complex input material like crushed e-waste is used. In superficial leaching ex-periments of holistic RAM’s a formation of a passive layer was observed, which hindered or slowed

get price