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Thiosulfate leaching process has been carried out in the alkaline medium since in low pH, thiosulfate has decomposed and formed elemental sulfur which covers the metal surface and prevents from the leaching (Hilson and Monhemius, 2006). Furthermore, the leaching kinetics of precious metals using thiosulfate solution, enhanced by the addition of ...
The pH of the ammonium thiosulfate leaching process is generally maintained between 9 and 10 such that the presence of ammonia is ensured in order to dissolve Cu as a Cu(II)-ammonia complex. Molleman and Dreisinger reported that ammonium thiosulfate leaching for Au recovery should preferably be performed at a pH …
Thiosulfate leaching works under alkaline conditions, which has less-sensitivity to impurity and is non-corrosive to the equipment, in addition, the leaching process of thiosulfate leaching is more similar to that of cyanidation [9], [10]. In contrast, thiosulfate leaching is a relatively green and environmentally friendly gold extraction ...
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 ...
This leads to the visualisation of a process which uses a relatively benign gold leaching system, potentially based on thiosulfate as a ligand. The copper-ammonia-thiosulfate system suffers from several drawbacks, most notably, the reduction of copper(II) ammine by thiosulfate, producing copper(I) thiosulfate and tetrathionate ( Byerley et al ...
In the plant, the mined refractory gold ores are treated with alkaline POX to oxidize the sulfide, then the thiosulfate gold leaching process is applied to avoid the …
The leaching behavior of gold from an oxide gold ore using copper–tartrate–thiosulfate solutions has been investigated. Experimental parameters, …
Efficient and Selective Recovery of Gold from Thiosulfate Leaching Solution Using Functionalized β‐Cyclodextrins Synthesized by a Steric Hindrance …
The thiosulfate leaching experiments caused the formation of a stable passive layer after 2–3 hours, which led to a mass increase (0.3 M thiosulfate and ammonia, 0.01 copper sulfate).
However, ammonia also has negative effects on the development and commercial application of the thiosulfate leaching system (Jeffrey et al., 2001; Liu et al., 2018). Reactions 5,6,7 and 8 detail the leaching behaviour of gold in a thiosulfate system. The gold is oxidised and complexed by ammonia, producing the complex Au (N H 3) 2 + …
Thiosulfate leaching-resin adsorption recovery, an environmentally friendly process, has been developed to efficiently extract gold from an oxide gold concentrate. 80.5% of gold extraction could be achieved by thiosulfate leaching under the conditions of (NH 4) 2 S 2 O 3 0.2 mol/L, CuSO 4 0.025 mol/L, NH 3 1.5 mol/L and leaching time 8 h, …
1 Citation. Explore all metrics. Abstract. As the most promising alternative reagent to cyanide, thiosulfate has received renewed interest. However, the traditional …
In this study, an environmental friendly effective process was developed, which consisted of oxidation pretreatment, thiosulfate leaching and electrodeposition for silver recovery from anode slime and was proposed in the flow chat in Fig. 1.In the step of oxidation pretreatment, MnO 2 was used to treat anode slime in dilute sulphuric acid. As …
Gold Leaching by Thiosulfate and Glycine from Mineral. ... This dissolution process is favored by increasing the concentration of thiosulfate from 5 g/L to 20 g/L. It has been observed that of the gold present in the sample can be recovered when 20 g/L thiosulfate is used. By varying the solid–liquid ratios from 1:2 to 1:3, a process of ...
thiosulfate leaching; nickel- and cobalt-based catalysts; gold recovery; resin adsorption. 1. Introduction. Cyanidation has been the predominant gold leaching technique since it was …
Leaching process. The process of releasing solid material constituents into a contacting fluid phase is known as leaching. It is indifferent to all constituents—such as major and minor matrix components, as well as inorganic, organic, and radionuclide contaminant. ... Thiosulfate leaching. Thiosulfate solutions can be used as an …
According to the kinetic fitting of the leaching process, it was found that the sulfuric acid leaching process belonged to the diffusion-controlled model of solid product layers under conventional ...
This study aims to comprehensively investigate the role of glycine (GL) in gold dissolution with thiosulfate (TS), utilizing both experimental and density functional theory (DFT) approaches. Three different leaching systems, namely AM–TS–Cu2+, GL–TS–Cu2+, and AM–GL–TS–Cu2+, were examined and compared using the …
ABSTRACT This literature review provides an update of ammoniacal thiosulfate as a potential lixiviant of gold, the history of thiosulfate leaching and recent progress on thiosulfate leaching of gold, as well as the production, oxidation, and stabilization of thiosulfate. The leaching results of different types of gold ores including oxide, sulfide, …
A process based on thiosulfate leaching followed by resin-in-pulp gold extraction was developed to treat the carbonaceous, preg-robbing ores of Barrick's Goldstrike orebody in the Carlin Trend of … Expand. 71. Save. Treatment of a refractory gold—copper sulfide concentrate by copper ammoniacal thiosulfate leaching.
The results indicated that the gold extraction can exceed 80% after 6 h leaching. Compared with the traditional copperâˆ'ammoniaâˆ'thiosulfate leaching system, the oxygen pressureâˆ'thiosulfate leaching process has some advantages …
The addition of copper and citrate in thiosulfate solutions can accelerate gold dissolution rate by about an order of magnitude. For the copper-citrate-thiosulfate …
A key measurement index is the consumption of thiosulfate. As a result of adding STPCBs to leaching solutions, immediate consumption of the dissolved bio-thiosulfate took place at the first hour and then was fixed until the end of the Bio-Thio leaching process. Thiosulfate can decompose in alkaline solutions to produce sulfur …
Table 1 illustrates the side reactions occurring in thiosulfate leaching systems. These reactions not only result in the loss of lixiviant, but the formation of solid precipitates can also potentially passivate gold surfaces, limiting the gold leaching efficiency (Jeffrey et al., 2008).In addition to thiosulfate oxidation adding to reagent cost, …
Thiosulfate leaching was first proposed as a part of Von Patera process, where the leaching was implemented after …
Low-concentration Au(S 2 O 3) 2 3− recovery is an urgent issue to facilitate the application of thiosulfate leaching instead of cyanide leaching in factories. Herein, this work presents a novel recovery of low-concentration Au(S 2 O 3) 2 3− combining adsorption and electrodeposition (electroreduction) to realize high Au(S 2 O 3) 2 3− recovery in the …
Effect of the Sodium Thiosulfate Concentration. Figure 4 presents the effect of increasing the sodium thiosulfate concentration. The other leaching parameters were held constant at a temperature of 20°C, rotation speed of 300 rpm, leaching time of 5 min and ultrasound power of 200 W. Compared with that of the traditional leaching process, …
Compared with cyanide heap leaching, the thiosulfate process required only about 1 hour to achieve 90% gold recovery using up to 0.5M thiosulfate whereas …
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 ...
Some sedimentary minerals have attractive contents of gold and silver, like a sedimentary exhalative ore available in the eastern of Hidalgo in Mexico. The gold and silver contained represent an interesting opportunity for processing by non-toxic and aggressive leaching reagents like thiosulfate. The preliminary kinetic study indicated that the leaching …
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