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The influence of thiosulfate, ammonia and copper sulfate concentrations on the leaching of gold from PCBs of waste mobile phones was investigated Gold extraction was found to be enhanced with solutions containing 15-20 mM cupric, 01-014 M thiosulfate, and 02-03 M ammonia...
Know MoreA 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 amount of monomer gold was only 21%The gold-bearing sample was identified as a high-sulfur fine-sized wrapped-type refractory gold ....
Know MoreAug 18, 2015· Eco-friendly Gold and Silver Processing Technology Using Ammonium Thiosulfate Leaching - Pilot station presentation...
Know MoreThe ammonium thiosulfate contents in the leach liquors were in agreement with the quantity of gold leached in the respective pH rang In this process the copper sulfate worked as a catalyst The experiment conducted with complete PCBs scrap exhibited a maximum leaching of 788% gold at the above optimised condition...
Know MoreThe sponge gold (9992 % pure) has been leached with ammonium thiosulfate solution In this investigation, the gold leaching rate (extraction rate) and the thiosulfate oxidation rate (consumption rate) have been studied on the effects of CuSO 4, (NH 4) 2 S 2 O 3, (NH 4) 2 SO 4, NH 4 OH, stirring speed and retention time The copper ion acts as a catalyst in gold dissolution, on the other hand ....
Know MoreNov 21, 2014· Ammonium thiosulfate ecological alternative to replace sodium cyanide in gold and silver dissolution in low-grade ores, MC Hernández, E Acosta, MC Avitia, H Peña,I Portillo,L Rodríguez ....
Know MoreJul 16, 2016· For clarity, the different components in the thiosulfate leaching system are discussed separately Thiosulfate leaching In alkaline or near neutral solution of thiosulfate, gold dissolves slowly in the presence of a mild oxidant (White, 1905) The dissolution of the gold can be described as follows where oxygen is the oxidant and thiosulfate the...
Know MoreA non-hazardous solution used successfully as a lixiviant in the process of thiosulfate leaching as an alternative to the use of cyanide Captor® | Calcium Thiosulfate Solution Captor is a non-hazardous liquid used to reduce/destroy chlorine, ozone and peroxide to zero-residual levels in ,...
Know MoreAmmonium 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 03M (NH4)2S2O3, 003M CuSO4 and 3M NH3 at pH 102 for 24 hours In the testing, thiosulfate consumption was 30 kg/t of ore...
Know MoreIn the previous study of the copper catalyzed ammonium thiosulfate leaching system, it was confirmed that gold could be recovered efficiently at high thiosulfate and low copper and ammonia concentrations by zinc, copper and aluminium powders33) This fact indicates that the aurous ion is stable in the form of a thiosulfate complex...
Know MoreIn the previous study of the copper catalyzed ammonium thiosulfate leaching system, it was confirmed that gold could be recovered efficiently at high thiosulfate and low copper and ammonia concentrations by zinc, copper and aluminium powders33) This fact indicates that the aurous ion is stable in the form of a thiosulfate complex...
Know MoreThiosulfate leaching of gold from waste mobile phones...
Know Morethe leaching of gold from the PCBs is better Thus, tests were performed with lower concentrations of thiosulfate and ammonium for the 4-hour leaching time and tests with higher concentrations of thiosulfate and ammonium for 24 hours The sodium and ammonium thiosulfate were tested under different conditions of concentration, time, pH and...
Know MoreSix variables were investigated in fractional factorial screening tests, including thiosulfate (s2o2-3), sulfite (so2-3), copper (cu2+), and ammonia (as nh4oh) concentration; air- inert atmosphere; and leaching time Thiosulfate and sulfite concentrations and leaching time influenced gold extraction, while copper affected thiosulfate consumption...
Know MoreIn a resin-in-leach system, full gold recovery was also achievable with sufficient resin after 24 h leach with 006 M fresh ammonium thiosulfate and 2 mM EDTA at an agitation speed of 250 r/min Key words: Gold leaching, Thiosulfate, Additives, Leaching kinetics, Thiosulfate stability...
Know MoreThe effects of copper sulfate and ammonium thiosulfate [(NH 4) 2 S 2 O 3], the environment PH, and pulp mass were analyzed 567 % of gold was extracted in suitable and optimal conditions, which are in 01 molar thiosulfate, 40 ml copper sulfate, and 8 hours time Gold extraction efficiency of PCBs in the range of PH = 10-105 may be attributed ....
Know MoreJan 11, 2012· During leaching ferric oxide, Iron hydroxide and elemental sulfur will be in solids and copper in solution acting as oxidizer (oxygen rejuvenating the cupric Ion) and gold will be left with the thiosulfate IF this leach is working and IF all conditions are maintained in solution, (< 9 pH, and temperature also seem to be factors)...
Know MoreThe proposed method of the gold recovery comprises leaching with a solution of a mixture of sodium and ammonium hydrosulfite and thiosulfate, by sorption of the thiosulfate-gold complex on a highly basic anion exchanger and by isolation of the highly basic anion exchanger, the sorption being carried out 2-10 hours after the leaching Then the ....
Know MoreAmmonium thiosulfate is a white crystalline solid inorganic compound with the chemical formula H 8 N 2 O 3 S 2, and CAS 7783-18-8 The slightly toxic compound is used in photography, leaching of gold and silver, and as a fertilizer...
Know MoreAmmoniacal thiosulphate leaching of gold finds a better substitute as it is non-toxic and environmentally safe as compared to the toxic cyanide system for gold extraction In the present study, an attempt is made to assess the feasibility of ammoniacal thiosulphate leaching of gold ore samples from two...
Know MoreA Novel Thiosulfate System for Leaching Gold Without the Use of Copper and Ammonia Ji, J / Fleming, C / West-Sells, P G / Hackl, R P / TMS | 2003 print version...
Know Moreboth ammonium thiosulfate (60 gL-1) and ammonium hydroxide, and by controlling the pH with Ca(OH) 2 Best extractions were achieved with liquid-solid ratio of 10:1, which provided an extraction of 86 % gold, 901 % silver, and 884 % copper NH 4 OH was used for complexation of copper and controlling the pH above 10...
Know MoreThiosulfate 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...
Know MoreThe proposed method of the gold recovery comprises leaching with a solution of a mixture of sodium and ammonium hydrosulfite and thiosulfate, by sorption of the thiosulfate-gold complex on a highly basic anion exchanger and by isolation of the highly basic anion exchanger, the sorption being carried out 2-10 hours after the leaching Then the ....
Know MoreThe 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 circumstanc However there are also ....
Know MoreThe kinetics and mechanism of gold leaching in the ammonia-thiosulfate-copper (ATS-Cu) system have been studied using the rotating electrochemical quartz crystal microbalance (REQCM) Anodic polarization, cathodic polarization and leaching experiments were included in this study The effect of concentration of different reagents, applied potential, pH, temperature, and electrode rotating ....
Know MoreSep 09, 2019· Thermodynamic analysis of the copper (I) homogeneous and heterogeneous speciation in ammonium thiosulfate leaching systems Igor Povar, a Stefano Ubaldini, b Oxana Spinu, a Tudor Lupascu a a Institute of Chemistry, 3 Academiei str, Chisinau, MD2028, Republic of Moldova...
Know MoreHere, we present a study of gold leaching, where the gold layer is removed from a microchannel wall within a high aspect ratio channel (8 μm × 4 mm cross-section; 1:500) The etchant is an aqueous solution of sodium thiosulfate, ammonium hydroxide, and copper sulfate...
Know MoreGold 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 complexIt is the most commonly used leaching process for gold extraction Production of reagents for mineral processing to recover gold, copper, zinc and silver represents ....
Know MoreThe 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 grad The behaviour of thiosulfate, tetrathionate and sulfate in solution was studied using ion chromatography The copper sulfide ,...
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