Laboratory testing has indicated that a thiourea process for gold and silver extraction has several advantages over the conventional cyanidation w3,4x. The thiourea advantages are a low environmental impact, an easier handling of …

A number of acyl(aroyl)thiourea ligands were used for the extraction of gold(III). Extraction was observed with all the ligands under the experimental conditions ...

Various efforts have been made to reduce the use of mercury in gold extraction, one of which is the leaching method using thiosulphate and thiourea solution because they have low toxicity …

Gold extraction from the rock is generally carried out using mercury. However, the high toxicity of mercury has a very dangerous impact on the environment and health. Various efforts have been made to reduce the use of mercury in gold extraction, one of which is the leaching method using thiosulphate and thiourea solution because they have low toxicity and are environmentally …

The gold extraction rate obtained within this study (91.94%) is comparable in terms of the gold extraction rates (69–95.5%) achieved in the previous work [15, 21, 23, 24] on the subject, where thiourea (CH 4 N 2 S)-hydrogen peroxide (H 2 O 2) leaching system were used for the extraction of gold from various primary and secondary resources ...

The nature of gold (Au) ore deposits plays an essential role in determining the best gold recovery method as an alternative to cyanidation, considering environmental concerns. Thiourea (Tu) leaching of gold is an alternative lixiviant for treating sulfide gold ores and concentrates. The present study investigated the leaching behavior of Au from sulfide gold ore …

Request PDF | Thiourea-Based Extraction and Deposition of Gold for Electroless Nickel Immersion Gold Process | Gold electroless plating for surface finishing of electronic circuits, named ...

Alkaline sulfur-containing lixiviants, including thiosulfate, polysulfides, and alkaline sulfide solutions, stand out as a promising class of alternatives to cyanide because of their low toxicity, high efficiency, and strong adaptability. In this paper, we summarized the research progress and remaining challenges in gold extraction using these noncyanide reagents. After a …

Hydrometallurgical gold recovery processes play a pivotal role in the gold mining industry, contributing to more than 90% of global gold production. Among the array of techniques available, the Merrill–Crowe process, adsorption, ion exchange, and solvent extraction are central in extracting gold from leach solutions. While the Merrill–Crowe process and gold complex …

Recent developments in solvent extraction using modified amines and alkyl phosphorus esters have been reported to provide for selective gold extraction from alkaline cyanide solution [5]. Patented Gold Extraction/Recovery …

Gold is a highly required material for a wide range of personal and industrial applications. The high demand for gold, together with the shortage of natural resources and high pollution potential of wastes generated during mining and ore processing activities led to search for alternative sources of gold. A possible source is represented by mine wastes resulting from …

Thioura leaching was developed as a potential substitute to cyanide leaching due to its lower toxicity and greater rate of gold and silver dissolution. Other alternative lixiviants to cyanide such as bromides (acid and alkaline), chlorides …

Alkaline sulfur-containing lixiviants, including thiosulfate, polysulfides, and alkaline sulfide solutions, stand out as a promising class of alternatives to cyanide because of their low toxicity, high efficiency, and strong adaptability. In this paper, we summarized the research progress and remaining challenges in gold extraction using these noncyanide reagents. After a …

Thiourea leaching of gold from a quartz vein type ore without the addition of additive was investigated to show the effect of leaching conditions including Fe 3+ concentration (0.02–0.05 M), thiourea concentration (0.05–0.13 M), pH (1.0–2.5), leaching time (4–7 h) and temperature (25–50 °C) on gold extraction and thiourea consumption.

Various efforts have been made to reduce the use of mercury in gold extraction, one of which is the leaching method using thiosulphate and thiourea solution because they have low toxicity and are ...

Request PDF | On Oct 1, 2013, Bong-Ju Kim and others published A Study on Extraction of Gold-silver from Refractory Gold Concentrate by Using Thiourea Solution | Find, read and cite all the ...

effect of the two additives on gold extraction and thiourea consumption as well as gold recovery from its pregnant leach solutions via activated carbon adsorption were studied. Based on leaching ...

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 ...

The use of thiourea, (CS(NH2)2 as a complexing/extracting agent for gold and other precious metals has shown promise for implementation in the mining/metals industry. Laboratory testing of this reagent has indicated that a thiourea process for gold extraction has several advantages over conventional processing techniques.

The results of the study reveal that (I) Cysteine is an effective stabilizer for thiourea solutions, but it has a negative effect on the extraction of gold from the ore and on the recovery of ...

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 …

The most promising results were obtained utilizing solution with sodium sulfite and sodium sulfate concentration of 25 g/L and leaching time – 1 hour. Under these conditions, the extraction of gold was 67%. The use of sodium sulphate and sodium sulfite allows to extract gold and partially silver from refractory sulfide ores.

Abstract The synthesis and properties of some novel solvent extractants that are highly selective for gold and silver in very acidic chloride solutions are described. In this paper we also report on the study of one of these reagents; Dodecyl-thiourea (DTH), which has shown to be a very selective extractant for Au(III) and Ag(I) in the presence of Cu(II) and Fe(III). The …

Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods, such as cyclic voltammetry, chronopotentiometry, AC impedance, linear sweep voltammetry. Apparent activation energy of anodic process of gold electrode dissolving in alkaline thiourea solution is 14.91 kJ/mol. Rate determining step is the process of gold …

acid conditions, so that to extract the gold by cyanidation it is necessary to raise the pH of the bioleachate to around 10 by adding lime to prevent the formation of HCN. It would be very advanta-geous to be able to extract gold under acidic condi-tions by using thiourea. In the presence of a suitable oxidizing agent, such as O 2, H 2 O 2 or ...

Thiourea has received attention as an alternative lixiviant f or gold leaching due to its fast rea ction kinetics and. less harmful nature. This review aims to provide an up-to-date ev aluation...

Highly efficient gold extraction by rGO. The rGO was obtained by chemical reduction of commercial, mass-produced graphene oxide (GO) nanosheets using ascorbic acid as a reductant (Methods).

The use of thiourea (Thio), or thiocarbamide, for the treatment of gold-containing raw material is a promising field [1–11]. The dissolution of gold in thiourea solutions occurs in the presence of …

Abstract—In this study, the effects of thiourea (CH4N2S) on the efficiency of gold dissolution were investi-gated for the extraction of gold from an oxide gold ore of the eastern Anatolia region, …