The ammoniacal thiosulphate leaching of gold is dependant on both ammonia and thiosulphate concentration. The leaching is improved significantly at a particular ratio of ammonia to thiosulphate
Aug 01, 2006· The effect of pyrite on gold dissolution was investigated in the ammoniacal thiosulphate leaching system using pure gold foils. Special emphasis was placed on gold leaching in association with pyrite dissolution, thiosulphate decomposition and gold leaching passivation. The presence of pyrite retarded gold dissolution and this detrimental effect
The ammoniacal thiosulphate leaching of gold is dependant on both ammonia and thiosulphate concentration. The leaching is improved significantly at a particular ratio of ammonia to thiosulphate
leaching mechanism, which obstructs the development and application ofthe technology. The purpose of the research work reported in this paper was to find out the anodic and cathodic behaviours of gold in thiosulphate solution and reveal the leaching mechanism of gold with ammoniacal thiosulphate through electrochemical investigations
Mar 01, 2012· The rate of gold leaching by Cu(II) in ammoniacal thiosulphate depends on the concentration of the three reagents (Jeffrey, 2001). In general the concentration of Cu(II) is maintained relatively low (< 10 mM) compared to the two ligands S 2 O 3 2 − (0.1 M) and NH 3 (0.4–1 M). The concentration of free ammonia in solution can be enhanced by increasing the pH.
Dec 01, 2010· The type of thiosulphate salts was found to influence significantly the solution and surface chemistry, and hence the leaching of pure gold and the pyrite concentrate in the ammoniacal thiosulphate solutions. Calcium thiosulphate gave a higher gold extraction rate with negligible consumption of thiosulphate in the leaching of pure gold.
leach significant quantities of gold without consuming excessive quantities of reagents. Thiosulphate is a more effective lixiviant of preg-robbing and high-copper ores than cyanide because ammoniacal thiosulphate leaching is less sensitive than cyanidation to contamination by unwanted cations.
The leach process involves a chemical reaction between metallic gold and the thiosulphate anion, with oxygen as the oxidant, and ammonium and copper ions as unconsumed catalysts in the reaction. One possible scheme for the overall reaction is presented below: 4Au + 8S. 2. O.
leaching of gold in ammoniacal thiosulphate Fluorescent Minerals Fluorescence Fluorescent Lamp Fluorescent Minerals Free ebook download as PDF File (.pdf), Text File (.txt) or read book online for free.
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
In this current study, the extraction of gold from a high grade copper-rich gold ore by copper-assisted ammoniacal thiosulphate leaching was studied by adopting Taguchi L 9, (3 3) experimental
The gold dissolution rate of the gold ore could reach 94.3% and the thiosulphate consumption could be reduced to 1.12 kg/t ore in the thiosulphate gold leaching system containing 0.1 mol/L of
In this current study, the extraction of gold from a high grade copper-rich gold ore by copper-assisted ammoniacal thiosulphate leaching was studied by adopting Taguchi L 9, (3 3) experimental
ammoniacal copper(II)/thiosulphate system offers fast leaching kinetics, but there are difficulties in controlling the complex solution chemistry and there are concerns over the use of ammonia. Recently, thiosulphate leaching of gold in the absence of ammonia has shown to be one of the most promising alternatives to cyanide, as evident from the
Gold leaching in ammoniacal thiosulphate solutions is an electrochemical reaction, with the constituent half reactions being the oxidation of gold to gold thiosulphate, and the reduction of the cupric tetra-amine to the cuprous thiosulphate, as expressed in Eqs.
Thiosulphate has received much attention as an alternative non-cyanide lixiviant for gold recovery over the last three decades. In particular, a number of studies have shown that an ammoniacal copper(II)/thiosulphate system offers fast leaching kinetics, but there are difficulties in controlling the complex solution chemistry and there are concerns over the use of ammonia.
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
It is believed that the ammoniacal thiosulphate leaching of gold depends not only on the dissolution behaviour of gold, but also 124 D. Feng, J.S.J. van Deventer / Hydrometallurgy 105 (2010) 120–126 critically on the behaviour of the associated sulphide minerals. The dissolution of sulphide minerals could expose gold to the leach solution and
leaching of gold in ammoniacal thiosulphate Fluorescent Minerals Fluorescence Fluorescent Lamp Fluorescent Minerals Free ebook download as PDF File (.pdf), Text File (.txt) or read book online for free.
electrochemical aspects of gold and silver leaching with ammoniacal thiosulphate and compares alternative lixiviants such as cyanide and chloride/hypochlorite. In general, the rate of leaching with 0.1 M thiosulphate containing 10 mM Cu(II) and 0.4 M NH3 was similar to the rate with air saturated 5 mM
(i.e. 100%) during ammoniacal thiosulphate leaching. Although ammoniacal thiosulphate leaching appears to be more effective than cyanide leaching for gold extraction, it also suffers from high thiosulphate consumption. Keywords: Leach, thiosulphate, copper-gold ore, gold, Taguchi design (received 31 March 2011, accepted 2 May 2011) Introduction
Sodium Thiosulphate Gold Leaching. Ammoniacal thiosulfate and sodium cyanide leaching of preg. thiosulfate gold leaching Grinding Mill China. Effect of arsenopyrite on thiosulfate leaching of gold. sodium thiosulfate gold leaching metrosouth co za. Ammonium Thiosulfate Google Groups. US20030051581A1 Gold recovery from thiosulfate leaching.
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 minerals
Economic and technical evaluation of pilot plant tests carried out by Newmont Mining (Bhakta, 2003) and by Barrick Gold (Fleming et al., 2003) showed great promise for thiosulphate leaching. The leaching of gold in ammoniacal thiosulphate solutions is an electrochemical reaction and is promoted by the presence of copper(II) ions.
In this current study, the extraction of gold from a high grade copper-rich gold ore by copper-assisted ammoniacal thiosulphate leaching was studied by adopting Taguchi L 9, (3 3) experimental design approach. The effects of concentration of
(i.e. 100%) during ammoniacal thiosulphate leaching. Although ammoniacal thiosulphate leaching appears to be more effective than cyanide leaching for gold extraction, it also suffers from high thiosulphate consumption. Keywords: Leach, thiosulphate, copper-gold ore, gold, Taguchi design (received 31 March 2011, accepted 2 May 2011) Introduction
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 minerals
Thiosulphate has received much attention as an alternative non-cyanide lixiviant for gold recovery over the last three decades. In particular, a number of studies have shown that an ammoniacal copper(II)/thiosulphate system offers fast leaching kinetics, but there are difficulties in controlling the complex solution chemistry and there are concerns over the use of ammonia.
Gold leaching in ammoniacal thiosulphate solutions is an electrochemical reaction, with the constituent half reactions being the oxidation of gold to gold thiosulphate, and the reduction of the cupric tetra-amine to the cuprous thiosulphate, as expressed in Eqs.
Economic and technical evaluation of pilot plant tests carried out by Newmont Mining (Bhakta, 2003) and by Barrick Gold (Fleming et al., 2003) showed great promise for thiosulphate leaching. The leaching of gold in ammoniacal thiosulphate solutions is an electrochemical reaction and is promoted by the presence of copper(II) ions.
It is believed that the ammoniacal thiosulphate leaching of gold depends not only on the dissolution behaviour of gold, but also 124 D. Feng, J.S.J. van Deventer / Hydrometallurgy 105 (2010) 120–126 critically on the behaviour of the associated sulphide minerals. The dissolution of sulphide minerals could expose gold to the leach solution and
leaching of gold in ammoniacal thiosulphate Fluorescent Minerals Fluorescence Fluorescent Lamp Fluorescent Minerals Free ebook download as PDF File (.pdf), Text File (.txt) or read book online for free.
electrochemical aspects of gold and silver leaching with ammoniacal thiosulphate and compares alternative lixiviants such as cyanide and chloride/hypochlorite. In general, the rate of leaching with 0.1 M thiosulphate containing 10 mM Cu(II) and 0.4 M NH3 was similar to the rate with air saturated 5 mM
D. Feng and J.S.J. van Deventer, “Ammoniacal thiosulphate leaching of gold in the presence of pyrite,” Hydrometallurgy, 82 (2006), 126–132. CrossRef Google Scholar. 6. Chen Xia, “Associated sulfide minerals in thiosulfate leaching of gold: problems and
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 amount of monomer gold was only 21%.The gold-bearing sample was identified as a high-sulfur fine-sized wrapped-type refractory gold
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.
THIOSULPHATE LEACHING Inquire Now; Thiosulfate leaching of gold A review ResearchGate. Thiosulfate leaching of gold The ammoniacal thiosulfate leaching process for gold and Further investigations are required on leaching under low reagent Inquire Now; Thiosulphate leaching of gold in the presence of
Review Gold leaching by copper(II) in ammoniacal thiosulphate solutions in the presence of additives. Part I: A review of the effect of hard–soft and Lewis acid-base properties and interactions of ions
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.
Review Gold leaching by copper(II) in ammoniacal thiosulphate solutions in the presence of additives. Part I: A review of the effect of hard–soft and Lewis acid-base properties and interactions of ions
A review is presented summarising the leaching of gold with ammoniacal thiosulfate solutions, and evaluating the current use and development of ion exchange resins for the recovery of gold and silver from such leach liquors. Comparisons are also made with other recovery processes, including carbon adsorption, solvent extraction, electrowinning and precipitation.
Based on the diagrams, a possible mechanism for the Co(III)/Co(II) electrochemical-catalytic leaching of gold with ammoniacal thiosulphate is proposed. The calculation also reveals the differences in the oxidization potential and structural stability of the Co(NH3)(6)(3+) and Cu(NH3)(4)(2+), which explains the much reduced thiosulphate
Senanayake, G. (2012) Gold leaching by copper(II) in ammoniacal thiosulphate solutions in the presence of additives. Part I: A review of the effect of hard–soft and Lewis acid-base properties and interactions of ions. Hydrometallurgy, 115-116 . pp. 1-20.
Gold leaching in ammoniacal thiosulphate solutions is an electrochemical reaction, with the constituent half reactions being the oxidation of gold to gold thiosulphate, and the reduction of the cupric tetra-amine to the cuprous thiosulphate, as expressed in Eqs.
Economic and technical evaluation of pilot plant tests carried out by Newmont Mining (Bhakta, 2003) and by Barrick Gold (Fleming et al., 2003) showed great promise for thiosulphate leaching. The leaching of gold in ammoniacal thiosulphate solutions is an electrochemical reaction and is promoted by the presence of copper(II) ions.
Thiosulphate has received much attention as an alternative non-cyanide lixiviant for gold recovery over the last three decades. In particular, a number of studies have shown that an ammoniacal copper(II)/thiosulphate system offers fast leaching kinetics, but there are difficulties in controlling the complex solution chemistry and there are concerns over the use of ammonia.
THIOSULPHATE LEACHING Inquire Now; Thiosulfate leaching of gold A review ResearchGate. Thiosulfate leaching of gold The ammoniacal thiosulfate leaching process for gold and Further investigations are required on leaching under low reagent Inquire Now; Thiosulphate leaching of gold in the presence of
D. Feng and J.S.J. van Deventer, “Ammoniacal thiosulphate leaching of gold in the presence of pyrite,” Hydrometallurgy, 82 (2006), 126–132. CrossRef Google Scholar. 6. Chen Xia, “Associated sulfide minerals in thiosulfate leaching of gold: problems and
Extraction of gold and silver from turkish gold ore by ammoniacal thiosulphate leaching fatma arslan1 and baris184 sayiner2 1mining faculty mining engineering department mineral and coal processing section istanbul technical university maslak istanbul turkey 2koza altn is184letmeleri as184 ovack gold mine bergama izmir turkey.
Abstract: Thiosulphate gold leaching is an alternative technology to the cyanidation of gold ores. Ethylenediaminetetraacetic acid is referred to as EDTA.A study on the leaching kinetics of gold involved in the system S 2 O 3 2--EDTA-Cu 2+ for the gold in this paper. The effect of temperature and of the addition of copper has been also analyzed, temperature has a remarkable effect over the
Based on the electrochemical investigation, the following mechanism of leaching gold with ammoniacal thiosulphate has been proposed. Ammonia reacts primarily with gold ions on th anodic surface of gold and the formed A (NH3)2+ rea~s then with S2O 3 in solution to form the stabler Au(S203) 2 .
Jul 18, 2013· Thiosulphate is an attractive alternative reagent to cyanide for processing gold ores. It is relatively cheap and non-toxic, forms relatively strong gold and silver complexes, and readily leaches gold ores in ammoniacal solutions, catalysed by Cu(II). It is particularly suited to carbonaceous ores where the recovery of gold by cyanide is poor.