Thiourea leaching of gold from processed municipal solid waste

Several studies demonstrated that Au can be recovered from thiourea leaching solution by adsorption on activated carbon [59,60,61] and organic materials (e.g., persimmon tannin ... Jing-ying L, Xiu-li X, Wen-quan L (2012) Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones. Waste Manag 32(6):1209–1212. ...

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Gold Leaching in an Alkaline Thiourea Solution

It was found that used as a buffer, can prevent thiourea from further decomposing into some insoluble species in contact with the oxidant and that the mixed potential of gold is …

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Thiourea Leaching: An Update on a Sustainable Approach for …

This review aims to provide an up-to-date evaluation of thiourea-gold leaching studies from electronic waste, with emphasis on the recent progression from the classic …

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Research status and prospect of gold leaching in alkaline …

In this paper, fundamentals, development and the recent research progresses of gold leaching in alkaline thiourea solution, which is the most prospective substitute for …

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A REVIEW OF GOLD LEACHING IN ACID THIOUREA SOLUTIONS

Since the initial report of thiourea as a complexing reagent for gold leaching, considerable research has been directed toward the use of thiourea as an alternative to cyanide for gold extraction from different auriferous mineral resources. At the same time, some fundamental investigations of the system have been reported. In this article, a review of both …

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A review of gold leaching in acid thiourea solutions

The passivation of S 0 on gold leaching in acidic thiourea solution has been found from several previous research (Li & Miller, 2006; Li et al., 2020). The predominance regions of the species of ...

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Gold Leaching in an Alkaline Thiourea Solution

Gold leaching by thiourea has been investigated in an alkaline solution. In the presence of both Na2SO3 and Na2S2O8, the chemi-cal dissolution of gold can be …

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Thiourea Leaching of Gold and Silver — Technology Update

Leaching with a relatively concentrated thiourea solution (1MCS (NH 2) 2) resulted in 83% gold and 75% silver extraction in four hours. With the treated flue dust residue, gold extraction was …

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Leaching of gold in thiocyanate solutions. Part 1: chemistry and

A mixed-metal solution was used to accurately simulate the spent lixiviant from thiosulfate/thiourea leaching of mine tailings. ... The leaching of gold by thiocyanate solutions is performed at ...

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Thiourea leaching of gold in presence of jarosite and role of oxalate

The effect of jarosite generated from bio-oxidation on gold leaching in acidic thiourea solution was studied, and the role of the oxalate additive was also investigated. The biogenetic jarosite was found to markedly raise the thiourea consumption and hinder the gold dissolution. The dominant cause for the detrimental effect of jarosite is ...

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Evaluation of gold adsorption on activated carbon from real …

Prior to leaching, the gold concentrate was subjected to a series of washes and cleaning with CaClO 3, and regulating the pH with Ca(OH) 2. In addition, oxygen was used as oxidant agent for cyanide leaching, and H 2 SO 4 as oxidant agent for thiourea leaching. The control of the potential of solution was performed using a multimeter connected ...

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Research status and prospect of gold leaching in alkaline thiourea solution

The mechanism of gold dissolution is the theoretical foundations for gold leaching in thiourea solution. The suitable oxidant should be the substances with moderate redox potential. An efficient ...

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A Review of Thiosulfate Leaching of Gold: Focus on Thiosulfate

Thiosulfate leaching is a promising alternative to cyanidation, and the main hindrances for its wide commercial application are the high thiosulfate consumption and the difficult recovery of dissolved gold. In this review, the four solutions to reduce the consumption of thiosulfate, including the control of reaction conditions, the use of additives, the generation of …

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Oxidation-free thiourea leaching of gold uthig sulphur dioxide

reagent, high selectivity towards gold, faster leaching kinetics, the possibility of uncovering gold and silver included in acid-soluble minerals, lower dependence of efficiency on the presence of impurity ions. Dissolution of gold in thiourea solutions proceeds in the presence of an oxidizing agent [5, 6] by the following reaction:

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Gold Leaching by Sodium Chloride and Calcium Hypochlorite Solutions

Previous studies have addressed the effect of the initial pH of the chloride —hypochlorite solution on the leaching of the gold present in the sulphide ores. ... İpekoğlu Ü (2005) Leaching of Ovacık gold ore with cyanide, thiourea and thiosulphate. Miner Eng 18(3):363–365. Article Google Scholar Baghalha M (2007) Leaching of an oxide ...

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Thiourea-thiocyanate leaching system for gold

In thiourea-thiocyanate solutions, the gold leaching rate remains constant with time, which means the mixed ligand exhibits behavior similar to thiourea solutions. Increasing ferric concentration leads to a small increase in the gold leaching rate when ferric sulfate concentration increases from 0.0055 M to 0.022 M with no increase

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A REVIEW OF GOLD LEACHING IN ACID THIOUREA SOLUTIONS

Kenna, C. and Moritz, P., 1991, "The extraction of gold from bioleached pyrite using novel thiourea leaching technology," In World Gold '91, Gold Forum on Technology & Practice, Second Australia IMM-SME Joint Conference, April 21–26, Melbourne, Australia : Australasian Institute of Mining and Metallurgy, pp. 133 – 137 .

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Recovery of gold from refractory gold ores: Effect of pyrite on …

to the thiourea solution are often carried out to increase the stability of thiourea. However, little attention has been paid to the effect of impurities in the gold ore or thiourea leaching system on thiourea. The gold in RGOs is usually locked by metal …

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Improved thiourea leaching of gold with additives from calcine by

Wang et al. (2019) used a copper-ethylenediamine-thiosulfate solution to extract gold from calcine with a low thiosulfate consumption; however, the achieved gold extraction efficiency was only 80.3%. Xu et al. (2015) used calcine with similar composition (the exposed gold is 78.8% and 13.8% of gold is occluded by a passivating layer of iron ...

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Leaching and recovery of gold from ore in cyanide-free glycine media

The next step after leaching in the hydrometallurgical gold processing is the recovery of gold from the solution. In the gold mining industry, activated carbon is the most widely used extractant to recover gold from pregnant cyanide leach solution, known as carbon-in-leach (CIL), carbon-in-pulp (CIP), and carbon-in-columns (CIC) processes ...

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Simulation of leaching process of gold by cyanidation

The yield of the gold extract with thiosulphate solution was greater than that of thiourea solution. The thiosulphate solution had an optimum concentration of 0.3 M and an optimum time of 2 h.

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Review of gold leaching in thiosulfate-based solutions

Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low …

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(PDF) Gold Recovery from Chloride Leaching Solutions by

Currently, the adsorption methods (e.g., CIP / CIL) are by far dominating the recovery of gold from leaching solutions, especially in cyanide media.

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Thiourea Leaching of Gold and Silver — Technology Update

The hydrometallurgical application of thiourea in processing precious metal ores and concentrates has reached the development stage. This paper reviews recent technical literature covering the process development of thiourea leaching. In addition, recent fundamental contributions are discussed. Most of the interest in thiourea leaching has involved treating high grade …

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Thiourea leaching of gold in presence of jarosite and role of …

per 0.5 h. During the leaching of gold foil or jarosite, 5mL of solution sample was withdrawn every 1 h for subsequent chemical analysis. After the leaching was complete, the gold foil was taken out of the solution, while the pulp was directly filtered through a 0.45 μm filter paper; the leached gold foil and residue obtained were

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Synergistical thiourea and thiosulfate leaching gold from a gold

At present, non-cyanide extracting gold methods include thiourea (TU) leaching [6], thiocyanate leaching [7], halogen leaching [8], and thiosulfate (TS) leaching [9], [10].Among them, thiourea [6], halogen [8], and thiocyanate [7] leaching are used to leach gold under acidic conditions, which are corrosive to the equipment, and many base metals ions are dissolved in …

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Leaching and CIL processes in gold recovery from refractory ore …

The experiments were conducted at laboratory conditions using ore samples of which approximately 80% were ground to −0.038 mm.The grade of the ore samples was 6.8 g Au/ton.At the first part of the experimental studies, assuming that the gold could be recovered with CIC and CIP processes, the effects of pH, thiourea, oxidizing agent consumption, and leaching …

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An innovative thiourea gold leaching process

The thiourea advantages are a low environmental impact, an easier handling of reagent, a greater selectivity towards gold and silver and fast kinetics of gold dissolution 5, 6.An additional advantage over cyanide exists when treating refractory sulphide gold-containing ore, requiring biooxidative pretreatment; this results in highly acidic solutions, requiring …

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a Review of Gold Leaching in Acid Thiourea Solutions

a Review of Gold Leaching in Acid Thiourea Solutions Li, Jinshan; Miller, Jan D. Abstract. Publication: Mineral Processing and Extractive Metallurgy Review. Pub Date: September 2006 DOI: 10.1080/08827500500339315. Bibcode: 2006MPEMR..27..177L full text sources ...

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A REVIEW OF GOLD LEACHING IN ACID THIOUREA …

Recent research results demonstrate that thiourea decomposition is quite slow in the presence of ferric sulfate for simple solutions. Ferric sulfate and formamidine disulfide …

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