Thiosulfate Leaching Of Gold

A Method for Leaching or Dissolving Gold from Ores or ...

lurgical gold extraction routes utilize a leaching step to produce a gold-bearing solution as an intermediate product while the recycling of secondary gold from electronic and precious metal scrap is based on the selective and fast dissolu-tion of the precious metal. Therefore, A Method for Leaching or Dissolving Gold from Ores or Precious

Thiosulfate-copper-ammonia leaching of pure gold and ...

In thiosulfate gold leaching, Cu2+ ions are commonly used as oxidizing agents, while the thiosulfate ion acts as a ligand forming a soluble gold thiosulfate-ammonia complex (Aylmore and Muir, 2001). It was suggested that gold leaching in the absence of Cu2+ ions, with an external current acting as a oxidizer, is not possible

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 can make cyanide unattractive in some circumstances. However there are also ...

Thiosulfate Leaching of Gold and Silver from Waste Mobile ...

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 ...

Associated Sulfide Minerals in Thiosulfate Leaching of ...

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 3.0 hours.

GOLD RECOVERY FROM PRINTED CIRCUIT BOARDS OF MOBILE …

In the sodium thiosulfate and ammonium thiosulfate tests, it was possible to extract 70 and 75% of the gold contained in the PCB, respectively, using solutions containing 0.12 M of sodium or ammonium thiosulfate, 0.2 M of ammonium and 20 mM of copper sulfate in 4 hours of leaching, at a temperature of 30(2(C and pH 10.

Thiosulfate leaching of gold - A review | Request PDF

Feb 01, 2001· Thiosulfate leaching can be considered a non-toxic process, the gold dissolution rates can be faster than conventional cyanidation and, due to …

US6632264B2 - Gold recovery from thiosulfate leaching ...

Processes for recovering gold from copper-gold ores thiosulfate leaching or gold ores copper catalyzed thiosulfate leaching using ion exchange technology are disclosed. The processes include subjecting the gold-bearing and copper-bearing thiosulfate solution to a pH and/or temperature adjustment to reduce tetrathionate concentration in the thiosulfate solution prior to contacting with an …

thiosulfate gold leaching - micheldeegens.nl

In thiosulfate gold leaching, Cu2+ ions are commonly used as oxidizing agents, while the thiosulfate ion acts as a ligand forming a soluble gold thiosulfate-ammonia complex (Aylmore and Muir, 2001). It was suggested that gold leaching in the absence of Cu2+ ions, with an external current acting as a oxidizer, is not possible

Thiosulfate leaching of gold—A review | Semantic Scholar

Abstract 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. The thiosulfate leaching process it catalysed by copper and has several advantages over the conventional ...

process for thiourea and thiosulphate leaching - Gold ...

Nov 09, 2015· The only smell present during the leach time is ammonia. PH has every thing to do with using thiosulfate. If you let your leach run too long,and let the PH drop too much during run time,it will then pull in some iron. Run time,PH,and temperature are the keys to using thiosulfate. P.S. All of my observations are with sodium thiosulfate.

Thiosulphate Leaching | Mining | SGS

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 process are benign.

Thiosulfate leaching of gold—A review - ScienceDirect

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 carbonaceous-type ores. In addition, thiosulfate can be cheaper than cyanide.

Ammoniacal thiosulphate leaching of gold ore

leaching of gold as its absence makes gold passive by the build up of sulphur coating on the surface as a result of decomposition of thiosulphate. It is known that thiosulphate is a meta-stable species that readily undergoes decomposition in aqueous solutions. Ammonia adsorbs onto the gold surface preferentially over

Non-cyanide gold leaching agent_The Nile Co., Ltd.

Non-cyanide gold leaching agent (also can be called Non-cyanide gold dressing agent or Non-cyanide gold dissolving agent) is mainly applicable to heap leaching, tank leaching, and carbon paste (agitation leaching) processes of fine grind gold and silver ore.

THIOSULFATE LEACHING OF SILVER FROM A SOLID …

The observed leaching results show that with increasing thiosulfate ions concentration the leaching efficiency increases for both Ag and Cu. At the highest thiosulfate ions concentration the leaching recoveries of Ag and Cu were 60 and 35%, respectively. It confirms the possibility of thiosulfate leaching application for silver extraction.

THIOSULPHATE LEACHING – AN ALTERNATIVE TO …

equivalent rates of gold leaching, and a typical thiosulphate leach solution will have a reagent concentration of 5 to 20 g/L versus a cyanide concentration of only 0.25 to 1 g/L. The higher concentration of thiosulphate required leads to higher reagent consumption, which is at least .

(PDF) Thiosulphate leaching for gold hydrometallurgy ...

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US8597399B2 - Method for thiosulfate leaching of precious ...

Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of ...

FUNDAMENTAL ASPECTS OF GOLD LEACHING IN …

Figure 2.25 Mechanism of gold leaching in ATS system in the presence of copper ion (Ouyang, 2001) 42 Figure 2.26 The electrochemical model for the copper catalysis mechanism of leaching gold with ammoniacal thiosulfate.( Aylmore et al, 2001a) 43 Figure 2.27 The effect of pyridine on gold leaching in ATS-Cu system 45

Goldstrike TCM Leaching | Ausenco

Successful gold production uses patented thiosulfate processing method Project Goldstrike TCM Leach Project. Location Elko, Nevada, United States . Timeframe 2011 - 2015. Client ... involved a $620 million investment that included major upgrades to the Goldstrike leaching circuits and new infrastructure.

thiosulfate leach of gold plate - YouTube

Feb 24, 2014· recovered powders from a sodium thiosulfate leach of gold plated pins. if all my experiments can be perfected, i will have a safe, non-toxic process to remove gold from gold plated objects and ...

Barrick Gold Corporation - Processing Innovation Nets ...

Oct 06, 2016· First time any company in the western world produces gold on a commercial scale using thiosulfate From left to right: Chief Metallurgists Janet Baron and Averne Flaharty-Escobar, Director of Strategic Technology Solutions Yeonuk Choi and Senior Director of Strategic Technology Solutions Peter Kondos accept the MetSoc Innovation Award on behalf of their team that developed the thiosulfate ...

thiosulfate leaching of gold - thgroup.co.za

Thiosulfate leaching to recover gold from ores is known for several decades but extensive researches have been started only for the past two decades. 4. The process of recovering gold from mobile phone PCBs is an innovative approach to obtain the precious metals. 18 Abhishek Tripathi.

THIOSULFATE LEACHING OF GOLD--A REVIEW__

Thiosulfate leaching of gold--a review 167 T A B L E 6 Potentials for the reduction of gold complexes to gold metal f r o m a solution containing gold at 10 -s M Ligand Ligand Concentration E° (versus SCE) E (versus SCE) (M) Thiourea Thiocyanate Thiosulfate Chloride Cyanide 10 -1 10 -2 10 -1 10 -2 10-1 10 -2 10 -1 10 -2 10 -1 10 -2 (v) (v) 0. ...

Gold leaching in thiosulfate solutions and its ...

Gold and silver leaching in thiosulfate solution is preferable kinetically and environmentally if conducted in a closed vessel system.The effect silver alloyed with gold was evaluated and the result showed that the dissolution rate of pure gold is higher than that form 4 and 8 wt% Ag alloys. And the dissolution rate of gold from 20 and 50% ...

Barrick Thiosulfate Leaching of Double Refractory Ore

The thiosulfate-gold complex formed in thiosulfate leaching is not attracted to carbon so this failure to remove the carbon is no longer an issue. Thus, the use of thiosulfate with autoclave-processed double refractory ores does not result in the loss of the gold complex in the tails.

Optimizing the thiosulfate leaching of gold from printed ...

Oct 01, 2014· The gold leaching process followed the pseudo-second order kinetic model at the low concentration range of the reactants such as 40–60 mM thiosulfate, 5–7 mM copper(II) and 0.22–0.247 M ammonia, and the pseudo-first order kinetic model at the mid concentration range (60–70 mM thiosulfate, 7–9 mM copper(II) and 0.247–0.263 M ammonia).

Sodium thiosulfate - Wikipedia

Sodium thiosulfate (sodium thiosulphate) is an inorganic compound with the formula Na 2 S 2 O 3. x H 2 O. Typically it is available as the white or colorless pentahydrate, Na 2 S 2 O 3 ·5H 2 O.The solid is an efflorescent (loses water readily) crystalline substance that dissolves well in water.. Sodium thiosulfate is used in gold mining, water treatment, analytical chemistry, the development ...

thiosulfate leaching gold process - cafeole-koeln.de

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.

The treatment of copper-gold ores by ammonium thiosulfate ...

The application of ammonium thiosulfate for the treatment of copper-gold ores has been investigated. Leaching studies were conducted with copper minerals, copper minerals with gold addition to solution and copper-gold samples of different copper and gold grades. The behaviour of thiosulfate, tetrathionate and sulfate in solution was studied using ion chromatography. The copper sulfide …

The Extraction of Gold from E-waste by Hydrometallurgy ...

In other words, less than 2 % of the gold remained in the gold leach solution. Then, the organic phase, which is charged with 2 M ammonium hydroxide solution and 0.5 M sodium thiosulfate, was transferred. The results were not positive, and 3.13 and 15.26 % of gold was transferred from organic to …

thiosulfate leaching - Gold Refining Forum.com

May 19, 2011· 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.

Gold strike with thiosulphate - CSIRO

Within the tanks, the slurry interacts with thiosulfate and a fine, bead-like material called resin that collects the gold. At full capacity, 13,400 tons of ore can be processed daily, with leaching taking place simultaneously in two sets of seven tanks.