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gold leaching have been studied. 2. EXPERIMENTAL 2.1. Materials Two gold bearing ore samples were obtained from Akeshi and Hishikari mines of Kyushu region of Japan. The as received lump samples were crushed using a primary jaw crusher followed by a roll crusher to get a product passing through 1680µm sieve. The materials were homogenised ...
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Keywords: iodine-iodide leaching, gold-iodide complex, gold precipitation, reducing agent, sodium hydroxide, colloidal solutions, waste printed circuit boards 1. Introduction In gold hydrometallurgy, cyanide leaching is a conven-tional approach to recover gold from its ores and concentrates and has been used for over 100 years in gold mines all ...
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Cyanidation process or leaching of gold ore in aerated alkaline slurry has been the dominant process in gold extraction for more than a hundred years. ... are then divided to be fed to two parallel milling–leaching plants. A ball mill followed by hydrocyclones provides the classification of the ground . Optimization Gold Cyanidation Proce ss ...
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Subsequently, numerous studies have been devoted to developing the iodine–iodide leaching process for the recovery of gold from gold chips, gold ores, and WPCBs [27–29]. Nevertheless, the main obstacles of the leaching process are high reagent consumptions, higher reagent costs, and the complex chemistry of gold leaching in iodide solution.
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It was found that gold leaching Pretreatment recovery followed first order kinetics and that the injection of air had the maximum beneficial effect on the leaching kinetics. In the third series of test work, acid pretreatment (HNO3 and HCl) and roasting (600– 1000 °C) from 0.5 to 2 h were carried out before cyanidation.
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This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide …
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Thiourea has received attention as an alternative lixiviant for gold leaching due to its fast reaction kinetics and less harmful nature. ... (2013) Recovery of gold and silver from spent mobile phones by means of acidothiourea leaching followed by adsorption using biosorbent prepared from persimmon tannin. Hydrometallurgy …
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This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects …
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CIL （Carbon in leaching） is developed based on all-slime cyanide leaching followed by Zinc replacement, including thickening before leaching, leaching and adsorption, desorption of gold-loaded ...
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The method consisted of two stages roasting for arsenic and sulfur removal, gold recovery by thiourea leaching, followed by an enhanced chlorination roasting for gold recovery in the presence of pyrite. In the two-stage roasting process, the phase transition of FeAsS and FeS 2 during the roasting process was analyzed. In the first stage ...
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The present study examined a process for precious metal recovery (silver and gold) from difficult minerals which exhibit refractory characteristics to cyanidation and ammonium thiosulfate leaching (low extraction and high consumption of leaching agent). It is well known that mangano-argentiferous minerals are mainly composed of manganese, …
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A kinetic study on the optimum leaching condition showed that it followed the shrinking core model, in which the rate-controlling mechanism was the diffusion process. These results are discussed ...
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This study presents the novel idea of a cyanide-free leaching method, i.e., glycine-ammonia leaching in the presence of permanganate, to treat a low-grade and copper-bearing gold tailing. Ammonia played a key role as a pH modifier, lixiviant and potential catalyst (as cupric ammine) in this study. Replacing ammonia with other pH …
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Gold is recovered from its raw materials by bioleaching or cyanidation, followed by other operations, i.e., adsorption on the activated carbon [1][2][3], zinc precipitation [3,4] and ion exchange ...
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The traditional process for gold recovery from cyanide leach liquors has been the countercurrent decantation process. Following leaching, countercurrent decantation takes place in a series of thickeners in which the leach pulp is washed by the countercurrent flow of barren solution. See more
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route: pressure oxidation followed by gold chloride leaching. In this study, environmental impacts investigated using simulation and LCA tools. The process was con-ducted using Outotec's HSC Sim 9.0 (Outotec 2020) based on experimental data gathered from the literature. This allowed
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This method of making soluble gold is known as leaching. In the process of leaching, a dilute form of sodium cyanide is added to the ore containing the gold. Since gold is soluble after the leaching process, it is free to move …
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The leaching efficiency of gold in the polysulfide system reached 96.8%. This process has proved to be a promising alternative for efficient and environmentally friendly extraction of gold from the refractory gold ore. ... the polysulfide leaching results show that pressure oxidation leaching of the CTGC followed by sodium jarosite ...
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Abstract. The pretreatment of the cyanide tailing by roasting and its effect on the followed comprehensive recovery of valuable metals were investigated. The results indicate that the leaching rate of gold reaches 46.14%, the magnetic susceptibility of iron is up to 86.27% when the roasting temperature is 750 °C, the roasting time is 1.25 h ...
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followed by secondary ball milling. After comminution the pulp is normally dilute and thickening (6-12% solids by mass) is performed to increase ... The process design of gold leaching and carbon-in-pulp circuits contaminants. These are removed by thermal regeneration of the eluted carbon, typically in a rotary kiln at temperatures of ...
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2.1 Cyanide leaching. Cyanide is a cheap but highly toxic reagent that is very effective in leaching gold from low-grade minerals and mining wastes. Therefore, cyanidation is the most widely used method for the extraction of gold from mining wastes.
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Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold leaching efficiency. Roasting–leaching experiments, pore structure measurements, scanning electron microscopy (SEM), and X …
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Alkaline pressure oxidation followed by thiosulfate gold leaching results in low gold recovery (59.5%). In this study, mechanical activation was applied to alkaline pressure oxidation discharge by ...
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The effect of temperature on gold leaching was investigated for a 1-h residence time, in 3 M sulfuric acid and 3 M NaBr and 500 rpm agitation speed. ... The resulting bare WPCBs were separated, cleaned with hot water followed by acetone to remove any grease, dirt, and other contaminants. All cleaned WPCBs were manually cut …
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Gold Leaching Process. Many opportunities exist throughout the world for small cyanide plants, possibly using a Gold Leaching …
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The results are also compared with the other potential cyanide-free processing route: pressure oxidation followed by gold chloride leaching. In this study, environmental …
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Two-step bioleaching of ore concentrate resulted in the highest gold leaching yields (approximately ~ and 34% for R. tolerans and R. mucosus, respectively), followed by spent medium leaching and one-step leaching. The yields remained low for e-waste with both strains (maximum 0.93% and 1.6% for R. tolerans and …
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Although there has been little fundamental research into gold leaching in the alkaline sulfide system, there is some knowledge of the chemistry involved as a similar system …
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Direct Cupric Chloride Leaching of Gold from Refractory Sulfide Ore: Process Simulation and Life Cycle Assessment. Marja Rinne., Heini Elomaa., Sipi …
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Thiourea, as an environmentally friendly gold lixiviant, has the potential to replace highly toxic cyanide. The effect of foreign ions including Cu 2+, Ag +, Pb 2+, Zn 2+, AsO 3 3− and AsO 4 3− on gold leaching in an acidic thiourea solution was investigated in this paper. Leaching results showed that the foreign ions had an adverse effect on …
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