Thiourea Leaching Of Gold And Silve

Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones. Waste Manage., 32 (6) (2012), pp. 1209-1212. View in Scopus Google Scholar. Li and Miller, 2002. J. Li, J.D. Miller. Reaction kinetics for gold dissolution in acid thiourea solution using formamidine disulfide as oxidant.

The aim of this experimental work was devoted to the preliminary evaluation of the feasibility of thiourea leaching for the extraction of gold from a domestic gold-bearing ore 4 g/t …

The leaching behaviors of gold and silver from a complex sulfide concentrate in copper-tartrate-thiosulfate solutions were investigated in this paper. Experimental parameters, including temperature, initial pulp pH, and …

recovery of silver, gold, and lead from a complex sulfide ore USING FERRIC CHLORIDE, THIOUREA, AND BRINE LEACH SOLUTIONS By R. G. Sandberg 1 and J. L. Huiatt 2

Keywords Cyanide ·Thiourea ·Silver ·Leaching ·Gold Introduction The cyanidation process is widely used throughout the world due to its simplicity of operation and low cost; however, when the deposit contains refractory minerals, M. R. Pérez (B) · J. C. J. Tapia · M. P. Labra · F. R. B. Hernández · A. M. T. Ruiz · I. M. Estrada

The influence of particle size, thiourea and Fe(3+) concentrations and temperature on the leaching of gold and silver from waste mobile phones was investigated. Gold extraction was found to be enhanced in a PCBs particle size of 100 mesh with the solutions containing 24 g/L thiourea and Fe(3+) concentration of 0.6% under the room temperature.

Thiourea leaching of precious metals such as gold and silver from ores has several advantages when compared with conventional cyanidation process. In recent years, the use of ultrasound in ...

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:

The first (reported) attempt made to use thiourea to dissolve gold and silver was in 1941. It must take place in acidic conditions, following the anodic reaction shown in Reaction 23 (Örgül and Atalay, 2002). ... Leaching of gold, silver and accompanying metals from circuit boards (PCBs) waste. Acta. Montan. Slovaca, 16 (2011) Google Scholar.

The present communication deals with the leaching of gold and silver from the printed circuit boards (PCBs) of waste mobile phones using an effective and less hazardous system, i.e., a thiourea leaching process as an alternative to the conventional and toxic cyanide leaching of gold. The influence o …

Thiourea leaching of gold (Au) from e-wastes can be considered an alternative to highly toxic cyanidation, provided that its reagents consumption can be largely reduced. ... Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones. Waste Manage., 32 (2012), pp. 1209-1212, 10.1016/j.wasman.2012.01.026.

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 …

Thiourea is a reducing and complexing agent and can be used for the processing of gold and silver. The redox potential of gold (I) and silver (I) thiourea complexes in acidic thiourea solutions are 0.380 and 0.023 V (vs …

Silver extraction is generally low in thiourea leaching of gold and silver ores [Açma et al., 1993; Yüce et al, 1994 Yüce et al,, Çelik, 1996Tanrıverdi et al., 2005]. Thiourea decomposes to ...

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.

Thus, formamidine acts as an oxidant and as a complexing agent. Application of thiourea for Au extraction from several materials such as domestic ore, chalcopyrite ore, crushed electronic waste, and ceramic wastes allows for the extraction of up to 90% of Au at optimal conditions (low pH, presence of an oxidant) [34, 37,38,39].However, unlike most typically used …

Thiourea leaching of precious metals such as gold and silver from ores has several advantages when compared with conventional cyanidation process. In recent years, the use of ultrasound in leaching processes is becoming increasingly popular in hydrometallurgy. This paper deals with combining these two techniques for silver leaching from solid ...

The hydrometallurgical application of thiourea in processing precious metal ores and concentrates has reached the development stage. This paper reviews recent technical literature covering …

As can be seen from these results, the maximum gold and silver extractions in the thiourea leaching step at pH 2.3 were 66% and 56%, respectively. How- ever, if the thiourea leaching was carried out at a lower pH of 1.3, higher gold and silver extractions of respectively 92% and 78% were obtained.

An alternative system to cyanide as a leaching agent is presented for the recovery of gold and silver from cyanicide minerals. These minerals are characterized by the presence of copper and carbonaceous minerals in their composition, therefore increasing both the consumption of reagents and energy requirements for the detoxification and destruction of …

The thiourea leaching of gold and silver from electronic waste, goldsmith's waste and ceramic waste using crushing as the pretreatment step was investigated. For electronic waste, it was possible ...

Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones [J]. Waste Management, 2012, 32: 1209âˆ'1212. [27] ALTANSUKH B, BURMAA G, NYAMDELGER S, ARIUNBOLOR N, SHIBAYAMA A, HAGA K. Gold recovery from its flotation concentrate using acidic thiourea leaching and organosilicon polymer [J]. International Journal ...

Early workers such as Plaksin and Kozhukhova (1941) used thiourea to dissolve gold and silver in H2SO4 and H2O2. They observed similar leaching behavior for both metals. Using solutions containing 10 g/l H2SO4 …

Thiourea was used to leach gold from ore containing 0.4% Cu and 5.6 g/t Au. The parameters studied were acid pretreatment, leaching time, pH, thiourea concentration and the oxidizing agents used. ... (18% S), the gold and silver grades are 5.65 g/t and 23 g/t respectively. The major metallic elements are, in order of importance, Fe, A1, Ti, Mg ...

Semantic Scholar extracted view of "Thiourea leaching of silver from mechanically activated tetrahedrite" by P. Baláž et al. ... The intensification of the gold thiourea leaching from a filtration waste (Kosice, Slovakia) using mechanical activation as …

great selectivity toward gold and silver, fast kinetics, and easy handling of reagents [18–20]. The optimal conditions, mechanism, thermodynamics, and kinetics of thiourea leach- ... composition behavior of thiourea during gold leaching with thiourea mixed with pyrite as an impurity was studied to evaluate the effect of pyrite on the ...

Gold leaching using thiourea (0.4 M thiourea, pH 1.5, 3 h) following pretreatment using HCl and Citrate and no pretreatment, M. Reprinted with perimission from [66]

Thiourea was employed as the lixivannt for the extraction of gold and silver in place of the conventional cyanide. Direct thiourea leaching has yielded gold and silver recoveries of 23% and 45% whereas thiourea leaching of the bacterial leach residues has resulted in enhanced gold and silver recoveries of 92% and 78%, respectively.

Thiourea leaching of the bacterial leach residues has yielded gold and silver recoveries of 92% and 78%, respectively, as compared to 23% and 45% in direct thiourea …

Thiourea (CS(NH2)2) is a promising gold extracting agent for its high leaching rate and eco-efficiency (Wronski and Luczak, 2010). The electron pairs between nitrogen and sulphur atoms have a better potential for a coordination bond between gold and silver during thiourea leaching (Lacoste-Bouchet et al., 1998; Deschênes and Ghali, 1988).