Copperammoniathiosulfate leaching of gold has been researched for several decades as a potential alternative to cyanidation. However, this technology has not yet been applied commercially due to many challenges such as complex solution chemistry, reagent degradation and losses, system instability with
Thiosulfate leaching has great potential for the treatment of carbonaceous ores due to the low adsorption of gold thiosulfate complex on carbonaceous matter "kçıl et al., . Also, the interference of foreign cations with thiosulfate leaching is rather limited compared with cyanide leaching.
In place of cyanide, thiosulfate was chosen as complexing agent for gold. Thiosulfate leaching can be considered a nontoxic process and the gold dissolution rates can be faster than conventional cyanidation. The electronic scraps, obtained from "end of life" mobile phones, were crushed and pretreated with nitric acid before the leaching.
Leaching of middlerefractory gold ore show that both of the consumption of thiosulfate and leaching rate was decreased compare to the traditional copper–ammonia thiosulfate system. Thiourea is not stable in base solution, but it was found that gold dissolution rates can be increased with a little thiourea,the mechanism is still unclear.
Successful gold production uses patented thiosulfate processing method. Goldstrike is Barrick's largest and most productive mining operation, with gold production of more than 40 million ounces since 1987 It is located on the Carlin Trend, approximately 40 km north .
Ore Leaching Process Gold recovery using the heapleach method is based on the process of applying a leachate that usually contains about 100 to 600 parts per million (ppm) ( to percent) NaCN in a waterbased solution to a large pile of crushed or runofmine rock and, occasionally, mill .
Leaching of middlerefractory gold ore show that both of the consumption of thiosulfate and leaching rate was decreased compare to the traditional copper–ammonia thiosulfate system. Thiourea is not stable in base solution, but it was found that gold dissolution rates can be increased with a little thiourea,the mechanism is still unclear.
THIOSULFATE LEACHING In recent years, thiosulfate has been considered the most attractive alternative to cyanide for leaching gold, with many investigations taking place Alternative lixiviants to cyanide for leaching gold ores
It is the most commonly used leaching process for gold extraction. Get Price; Iodine 7% Leach for Gold Gold Refining . Sep 20, 2007· GoldDigger Iodine leach goes to work immediately on Gold, then Platinums, then Silver, in that order. It tends to ignore the other "Trash" metals.
THIOSULFATE LEACHING In recent years, thiosulfate has been considered an attractive alternative to cyanide for leaching gold. A process using thiosulfate has been developed and commercialized for Barrick Gold's Goldstrike operation in Nevada, USA.
Adsorption of the gold–thiosulfate complex ion (Au(S2O3)23) on silver ferrocyanide (AgFC)impregnated activated carbon in aqueous solution has been studied in order to find an effectual adsorbent for the thiosulfate extracting gold from ores.
in the complexation of gold and silver with ammonium thiosulfate. In leaching solutions implemented with different liquidsolid ratios with ammonium thiosulfate are the cuprammonium complex of Cu+2 and Cu(NH 3) 4 +2 is beneficial to thiosulfate because acts as oxidant according to .
The ammonium thiosulphate based leaching of gold and silver from PCBs waste, using crushing as a pretreatment, was investigated. It was possible to achieve 98 % gold and 93 % silver recovery within 48 hours of ammonium thiosulphate leaching. This type of leaching is a better leaching procedure for recovery of gold and silver from PCB
They found that the profit of the thiosulfate leaching process was similar to that of the traditional cyanide method. Furthermore, it was found that after three hours of thiosulfate leaching, 63 weight% of gold was recovered of the original preautoclave ore. The goal, always, is .
The research into leaching of gold with thiosulfate as an alternative lixiviant to cyanide has predominantly involved the use of copper in the presence of ammonia which serves as the oxidant. However, there are concerns about the health and environmental risks of ammonia (or ammonium).
Aug 08, 2019· The present invention is directed to leaching precious metals, and in particular, to improving the process of leaching precious metals, including gold, from gold bearing ores and other gold bearing materials, by using thiosulfate based leaching solutions, with or without copper cations, in combination with alkaline earth metals hydroxides.
Abstract The present communication deals with the leaching of gold from the printed circuit boards (PCBs) of waste mobile phones using an effective and less hazardous system,, a copperammoniathiosulfate solution, as an alternative to the conventional and toxic cyanide leaching of gold.
thiosulfate products on the gold surface. The addition of small amounts of DMSA ( 10 μM) to the electrolyte resulted in minor changes to the voltammograms indicating a subtle interaction of the additive with the gold surface that may improve leaching.
Copper catalyzed ammonium thiosulfate leaching process has been proposed as an alternative gold extraction process to cyanidation. In order to recover gold from the ammonium thiosulfate solution, ion exchange process has been proposed as a gold recovery .
Ammonium thiosulfate is a white crystalline solid inorganic compound with the chemical formula H8N2O3S2, and CAS . The slightly toxic compound is used in photography, leaching of gold and silver, and as a fertilizer.
The leaching behavior of HgO in thiosulfate solutions under different experimental conditions (temperature, thiosulfate concentration, liquid–solid ratio, and initial pH) was examined, and the potential use of sodium thiosulfate for the remediation of mercurycontaminated wastes is discussed based on experimental results.
sodium bromide in gold leaching (PDF) STUDY OF GOLD LEACHING WITH BROMINE AND Jul 31, 2018 bromine/bromide leaching, gold dissolution rate, sulphide minerals, . to reach the target pH 4, diluted the sodium bromide concentration to ~5 USA Bromine process for gold .
that gold recovery is difficult by thiosulfate leaching without any pretreatment, and the recovery of gold only is %. After roasting and oxidizing, the gold leaching rate increases substantially. The leaching rate of gold reaches % with the optimal leaching technological parameters (Li et al.,