Abstract: With the increasing of proportion of refractory gold ore and public's attention to environmental issues,the cyanide process has been severely constrained by both technology and environmental protection.The use of non-cyanide process for the extraction of gold and silver is an inevitable trend.Over the past decades,there were series of …
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— 3.1. Case study 1: Chlorination for leaching process of gold In this case study, chlorine has been used as a leaching reagent for the leaching process of gold the …
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— Permanganate Chlorination Process. This process differs from the ordinary treatment of ore in vats by chlorine water only in the use of a different solution. M. Etard originally proposed a solution containing 45 lbs. of strong commercial muriatic acid, and 12 ozs. of crystals of permanganate of potash.
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Chlorination - Concept - Electronic Encyclopedia of Gold in Australia - e-Gold is a biographical, bibliographical and archival database that tells the story of gold through images, stories and multimedia interactives, connecting …
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— The thiourea leaching combined with pyrite enhanced chlorination roasting was first proposed to effectively extract gold from the second stage roasting slag, and the pyrite shown a great role in promoting gold extraction during chlorination roasting. In this process, gold could be effectively recovered from the sulfide refractory gold ore with ...
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— The chlorination roasting of raw materials is only a basic process in chlorination metallurgy. the chlorination separation of chlorides also take place at the same time in the process of chlorination roasting, which is mainly based on the different physical and chemical properties of metal chlorides.
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— The Mears Process: In this process, the roasted ore was charged into lead-lined iron cylindrical barrels, together with enough water to make an easily flowing pulp ; chlorine was then forced in under …
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Gold Mine Closure and Decommissioning: 1 - 5 years. After a mine has ceased operations, possibly because the ore body is exhausted or the remaining deposit becomes unprofitable (uneconomic) to mine, work then focuses on its decommissioning, dismantling and rehabilitation of the land in which it was situated.
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text of the Black Hills mining history. The most famous gold mine in the region was (and is) the Homestake at Lead. Discovered on April 9, 1876, it has been worked almost continuously to the ... by the new chlorination process. Consequently, several Deadwood businessmen built processing plants to treat the Bald Mountain and Ruby Basin
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— The resource utilization of cyanide tailings has significant environmental and economic benefits. The efficient recovery of gold from low-grade cyanide tailings containing 1.71 g/t Au was performed by a …
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— This study showed the kinetics of gold chlorination leaching from an anode slime complex containing copper, silver, barium, selenium, and tellurium. AgCl and BaSO4 control the rate of gold leaching, and the interface transfer and diffusion across the product was selected as the desirable kinetic model. The concentration of hydrochloric acid, …
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— Miller chlorination was chosen as the primary refining process as it can produce molten gold of sufficient purity for pouring into saleable bars within 2 h. Wohlwill electrolysis was applied only to deposits with known high Platinum Group Metal content, as these metals are not removed by Miller chlorination, producing gold of 99.99% purity.
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— With calcium hypochlorite for chlorination leaching, under suitable conditions of calcium hypochlorite: adding amount 8%, chlorination temperature 333 K and chlorination time 2 h, gold was effectively recovered, the leaching rate is 81%. The chlorination leaching method showed a unique advantage for treating the secondary sources.
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— By the middle of the 19th century, people tried to use chlorine gas to treat gold ore, which was the first application of chlorine gas as a gaseous chlorination agent …
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Until the 1890s most gold was extracted from the crushed ore by amalgamation with mercury. The process of dissolving fine gold in a solution of chlorine in water was developed in Europe in the 1840s but in Australia was not used to any extent until the 1880s, From that time the process was applied for extracting fine gold from Mt. Morgan ores and gold …
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— Gold leaching is a fundamental process in the extraction of gold from ores. It involves dissolving gold from its ore using a chemical solution, commonly known as a leach reagent. The gold leaching process has been extensively studied and refined over the years to improve efficiency and minimize environmental impact.
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Gold refining can be achieved by high-temperature chlorination of the molten metal (Miller process) followed by electrorefining (Wohwill pro cess). The Miller process consists of chlorine injection into the molten bullion by means of an immersed clay tube. This process has three stages: 1.
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— The direct chlorination of a pure gold was also studied up to a temperature of 1223 K.These experiments demonstrated that the precious metal is not attacked at that …
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— It is a bio-mining process more environmentally benign than roasting since it maintains the arsenic in the ore as a stable precipitate; the arsenic remains associated with the solid residues. ... (19) Au + 2 C l − → AuCl 2 − + e − (20) Au + 4 C l − → AuCl 4 − + 3 e − During chlorination, gold is leached into a soluble gold ...
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— The results show that gold chlorination reaction was controlled by the interfacial chemical reaction, and the apparent activation energy was 40.05 kJ/mol. Silver has an activation energy of about 8.97 kJ/mol, and …
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— The feasibility to recover the gold present in alluvial material, by means of a chlorination process, using chlorine as a reactive agent, has been studied. The influence of temperature and reaction time was studied through changes in the reactant solid. The techniques used to characterize the mineral samples and the reaction residues were ...
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— The term "cyanide" refers to a chemical compound containing one atom of carbon and one atom of nitrogen. The technical definition of cyanide is a triple-bonded molecule with a negative one charge, consisting of one atom of carbon in the +2 oxidation state and one atom of nitrogen in the −3 oxidation state (InfoMine, 2012).Cyanides most …
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— Miller Chlorination Process. In order to purify gold and remove the silver from it by any process analogous to the cementation with nitre or salt in a reasonable time, the alloy must be in such a fine state of division that the silver will be removed almost instantly, or diffusion must be assisted by actually keeping the alloy in a molten state ...
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— The chlorination process is very versatile and can extract gold from concentrates of almost any composition. An important advantage of this process is the possibility of the complex processing of concentrates, …
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— Electrolysis is also widely used in the production and refining of precious metals, for instance, electrolytic gold is produced using hydrochloric acid as an electrolyte, known as the Wohlwill process, …
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— The amalgamation process works well for an ore containing the gold in the metallic state, free from arsenic and much sulphur. To obtain the gold from the amalgam, the mercury is distilled off and used over again while the residual gold is melted. Gold Chlorination. In chlorination the ore is ground, sometimes concentrated, and always …
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Dunn (1982) and Dunn et al. (1991) have extracted gold by chlorination using pyrometallurgical processes at temperatures lower than the ones mentioned above, from …
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recover gold from alluvial materials by an alternative process such as chlorination, preventing environmental pollution problems gen-erated by gold extraction and concentration by other conventional methods. Extractions of gold close to 99% were achieved, at a temperature of 873 K and at a reaction time of 5400 s, with no significant …
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— For chlorination roasting, the chlorine gas can penetrate the gold tailings and then react with gold and silver [18], [19]. Many chlorination agents such as CaCl 2, NaCl, …
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— Finally, there are aspects related to health, safety and contamination that have certain influence in the process. Impure Gold from Electrowinning Process. The techniques employed are Cupellation, Inquartation and Parting, Miller Chlorination Process, Wohwill Electrolytic Process, Fizzer Cell, and Aqua Regia Process. The final election is …
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