— The advent of the use of coconut-shell-based activated carbon to recover gold from cyanide solutions (see Chapter 23), and the need to recover the gold from pregnant eluate solutions resulting from elution of the loaded carbon led to the adoption of electrowinning as the primary means of gold metal recovery. ... 15,000 g/t from the …

The U.S. Bureau of Mines investigated the selective electrowinning of Ag and Au from cyanide solutions contaminated with Cu with the goal of decreasing the amount of Cu co-deposited. Decreasing Cu co-deposited will reduce refinery costs. Direct current was applied to the cell in pulsed and square wave voltages at 0.7 A.h per 150 mL of solution.

 — Traditional methods for the recovery of gold from electronic scrap by hydrometallurgy were cyanidation followed by adsorption on activated carbon or cementation onto zinc dust and by electrowinning. In our studies, a static batch electrochemical reactor operating in an electrogenerative mode was used in gold …

 — ABSTRACT. The redox reaction mechanism of gold−cyanide [Au(CN) 2 −] during hydrocyclone electrowinning was investigated in this work by conducting Hull cell test, potentiodynamic polarization, and computational fluid dynamics (CFD) simulations.A leaching solution of waste printed circuit boards (WPCBs) was prepared as an …

 — Work is devoted to studying electrowinning of precious metals, in particular gold, in rich cyanide solutions on three-dimensional cathodes of electronegative metals.

 — Russian investigators included this method in a sequential elution procedure ( 7 ], using first an acid solution for cyanide, nickel and zinc elution, followed by an acidic thiourea solution for copper, silver and gold elution and, finally, an alkaline solution of ammonium nitrate for the elution of iron and cobalt.

 — The reactions that take place during the dissolution of gold in cyanide solutions under normal conditions have been fairly definitely established. Most agree that the overall cyanide equation for leaching and cyanidation of gold is as follows: 4 Au + 8 NaCN + O2 + 2 H20 = 4 NaAu(CN)2 + 4 NaOH . Cyanide Leaching Chemistry

 — In mining applications, electrowinning is used to recover silver and gold from cyanide-based leach solutions. The precious metals are first dissolved or "leached" from the ore or concentrate into a solution using cyanide. The leach solution loaded with gold or silver is known as Pregnant Leach Solution or PLS.

Gold and silver are generally recovered by electrowinning (EW) from cyanide solutions purified and concentrated by carbon adsorption. In addition, electrocoagulation is used for the treatment of high-grade gold …

"The U.S. Bureau of Mines investigated the selective electrowinning of Ag and Au from cyanide solutions contaminated with Cu with the goal of decreasing the amount of Cu codeposited. Decreasing Cu codeposited will reduce refinery costs. Direct current was applied to the cell in pulsed and square wave voltages at 0.070 A. h per 150 mL of solution.

 — The catholyte was prepared from KAu(CN) 2 in such a way that Au(I) concentration was 500 mg l −1, in 0.041 M of sodium cyanide solution. The anolyte used was 0.10 M sodium cyanide solution.All solutions were prepared from analytical grade reagents using 18 MΩ −1 cm −1 deionised water. The solutions were deoxygenated with …

In cyanide solutions, gold is present as a stable auro-cyanide complex anion with a relatively high cathodic potential (E0). The cathodic shift demands a higher cell voltage and consequently other cathodic reactions like the formation of H2 and the reduction of …

 — The leach solutions are then treated with electrowinning to recover the metals. ... Electrowinning of Gold is a method used to extract gold from its ore. It's a complex and accurate process in which a continuous electric current is applied to the gold bearing ore. The process involves the electrolysis of a solution of chloride salts to …

THE EFFECT OF ACTIVATED CARBON PARTICLE SIZE ON GOLD CYANIDE ADSORPTION AND ELUTION by Francis Elnathan A thesis submitted to the faculty of The University of Utah ... has been studied in alkaline solution, in order to understand the nature of gold losses on fine activated carbons, to improve the rate of gold recovery, and to …

 — Direct electrowinning of pure gold from a leach solution originating from gold-rich contacts of PCBs with only a cutting step and a thermal pretreatment prior to dissolution in aqua regia was shown by Lekka et al. to be feasible in a batch solution without co-deposition of other metals on the electrode . No quantitative data were, however ...

K. D. Naumov, V. G. Lobanov, and Ya. D. Zelyakh. UDC 661.859. Work is devoted to studying electrowinning of precious metals, in particular gold, in rich cyanide solutions …

SELECTIVE ELECTROWINNING OF SILVER AND GOLD FROM CYANIDE PROCESS SOLUTIONS By F. H. Nehl,1 J. E. Murphy,2 G. B. Atkinson,3 and L. A. Walters2 ABSTRACT The U.S. Bureau of Mines investigated the selective electrowinning of Ag and Au from cyanide solu­ tions contaminated with Cu with the goal of decreasing the amount …

 — The electrowinning method for treating high copper cyanide solution was investigated by thermodynamics analysis and experiment. The influences of copper concentration, solution temperature ...

Electrowinning tests with diluted synthetic gold cyanide solutions (Au concentration = 10 ppm) The results of experiments accomplished with and without the solution recirculation system are shown,

 — Electrowinning tests were accomplished with diluted synthetic gold cyanide solution (10 mg L-'), and with synthetic gold cyanide solution in the concentrations of 10 …

 — Semantic Scholar extracted view of "An electrogenerative process for the recovery of gold from cyanide solutions." by C. Yap et al. ... Gold electrowinning from diluted cyanide liquors: performance evaluation of different reaction systems. L. Barbosa L. Sobral A. Dutra. Materials Science, Chemistry. 2001; 23.

 — The use of various cathode materials for the galvanic recovery of gold from 500 mg l −1 of simulated gold cyanide solutions has been demonstrated. The system …

 — Experiments with the single electrode assembly used a cyanide heap leach solution containing 17 µg/mL Ag, 6.1 µg/mL Au, and 120 µg/mL Cu as electrolyte. The …

 — This study aimed at investigating the effect of some parameters on the direct electrowinning of gold from cyanide solutions and a comparative study of two kinds of three-dimensional electrodes (stainless steel mesh and mild still wool). The current efficiency and the energy consumption were also analysed considering three competing cathodic ...

 — Traditional methods for the recovery of gold from electronic scrap by hydrometallurgy were cyanidation followed by adsorption on activated carbon or cementation onto zinc dust and by electrowinning.

The most effective elution technique for Minix makes use of acidic thiourea after an acid wash (1 M) to remove nickel, zinc, and some copper.The gold-selective adsorption characteristics of Minix, particularly its high selectivity against cobalt and iron, make it possible to use its advantages (fast kinetics and circuit simplicity) without fear of …

 — Work is devoted to studying electrowinning of precious metals, in particular gold, in rich cyanide solutions on three-dimensional cathodes of electronegati.

Cyanidation has been used to extract gold (and silver) from ores, concentrates, and calcines since the 1890s. The precipitation of gold from cyanide solutions by zinc cementation was patented in 1884 and was applied industrially as …

 — Gold electrowinning was carried out with distinct cyanide solutions, namely: pure synthetic solution and synthetic solution with metallic impurities. This study aimed at investigating the effect of some parameters on the direct electrowinning of gold from cyanide solutions and a comparative study of two kinds of three-dimensional electrodes ...