Table 3 shows the gold recovery/ extraction by cyanidation using 300 ppm NaCN, 30% solids, and pH 10.5. The results showed cyanide consumption was low for these types of free milling gold ores. The glycine-permanganate leaching system was applied to each ore. The total permanganate added to each was 3 kg reagent /tonne ore. The gold …
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In all cases there exist optimum oxidant/iodide ratios for achieving maximum gold extraction rates. A mixture which has the highest I 3− and free I − concentration …
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Therefore, the main aim of this research work is to evaluate the application of the glycine leach process for gold extraction from essentially copper-free (Cu < 0.01%) oxide (S < 0.5%) ores at temperatures aligned to ISL leaching with dissolved oxygen/air as oxidant instead of hydrogen peroxide at elevated pH.
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Gold extraction from an oxide ore in iodine-iodide solutions Baghalha, M ; Sharif University of Technology
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Chlorine is the lightest, cheapest and least reactive while iodine is heaviest, most expensive, and fastest reacting. Iodine is classified as a rare element. There are no ores containing iodine. It is obtained primarily from extracting seaweed, hence, the high cost. Chlorine was the first commercial gold extracting agent.
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The effect of pH value on gold extraction for various ore types is shown in Figure 28.4. Greatly increasing pH value has a beneficial effect on gold extraction for both oxide and sulfide ores and stabilizes ∼pH 9.5–10.0, whereas for some carbonaceous ores, pH value has no apparent effect. However, the outcome will vary depending on the ...
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The invention discloses a method for extracting gold from copper-oxide oxidized gold ores. The method comprises the following steps: 1, carrying out ammonia-cyanide leaching on the copper-oxide oxidized gold ores to obtain an ore pulp; 2, adding hypochlorite into the ore pulp, and stirring to remove copper in order to obtain a copper removed ore pulp; …
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Here we report an exceptionally high gold extraction capacity of chemically reduced graphene oxide (rGO), reaching 1850 mg/g and 9059 mg/g when extracting gold from its 10 ppm solution at 25 °C ...
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Gold leaching from ore using iodide-iodine mixtures is an alternative to gold cyanidation. This study evaluated the ability of iodide-oxidising bacteria to solubilise gold …
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In this study, persulfate was used to replace iodine as the oxidant for the extraction of gold from refractory gold ore. Using single-factor tests, the optimal leaching conditions were determined as a solid–liquid ratio of 1:3, a stirring speed of 350 rpm, 0.02 mol/L ammonium persulfate, and 0.1 mol/L potassium iodide.
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In this research, an eco-friendly and reagent recyclable gold extraction process was proposed, which is the iodination leaching-electrodeposition recovery of gold ore. The main results of this study can be summarized as follows: ... The leaching kinetics of an oxide gold ore with iodide/iodine solutions. Hydrometallurgy (2012) F. …
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The extraction of gold from ores by biosynthesized reagents is discussed. ... Angelidis et al. (1993) showed that the iodine could dissolve gold at a much greater rate than the rates achieved with the cyanide. It is a chemically-controlled reaction, even in inadequate mixing conditions. ... extraction of gold and silver from oxide ores by means ...
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Environmentally friendly ligands, alternatives to cyanide, are desired to extract gold for the sustainable hydrometallurgy of gold. Leaching characteristics of gold were examined using thiourea (TU) and ethylene thiourea (ETU) as ligands from three types of gold ores with different Fe contents from 2.70 to 14.09 wt% under the acidic condition.
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They evaluated the extraction of gold from oxide ores using alkaline glycine in the presence of permanganate ions. Their result demonstrated that gold extraction after 48 h was reduced by ...
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Auric Oxide, Au2O3. This is, the best known gold oxide, is a black powder when anhydrous, and is precipitated from solutions of auric chloride in the form of a hydrate by the caustic alkalies, the carbonates of the alkalies, and hydrates of the alkaline earths or zinc. The readiest method of preparation of this compound is to add caustic potash ...
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If the solution is rich enough can be treated by zinc powder and the precipitated obtained (cement) obtained will be sent to retorting and smelting. For gold extraction the strength of cyanide solution ranges from 0.01 to 0.05%. Lime is added to the process in order to have a pH near to 10-11.
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Abstract. In this study, the effects of thiourea (CH 4 N 2 S) on the efficiency of gold dissolution were investigated for the extraction of gold from an oxide gold ore of the eastern Anatolia region, Turkey. In the thiourea leaching experiments; several parameters such as particle size (–75, –53, and –38 μm), leaching time (30, 60, 120, 180, and 240 …
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In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 89% in 24 h. Iodate as the oxidant could not leach any gold in 48 h. Iodine reactions with the sulfide and the ferrous minerals of ore are the main …
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The leaching kinetics of an oxide gold ore with iodide/iodine solutions Baghalha, M ; Sharif University of Technology | 2012. 864 Viewed. Type of Document: Article DOI: 10.1016/j.hydromet.2011.11.013 ; Publisher: 2012; ...
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Among them, an iodine–iodide solution is a highly selective and efficient leaching agent for the recovery of gold from gold ores and WPCBs [21,23,24,25]. Several decades ago, the first patented process by Homick et al. (1976) used an iodine–iodide solution and a reducing agent (hydrazine) to recover gold from PCBs [ 26 ].
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zinc processing, the extraction of zinc from its ores and the preparation of zinc metal or chemical compounds for use in various products. Zinc (Zn) is a metallic element of hexagonal close-packed (hcp) crystal structure and a …
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Baghalha (2012) used a solution containing 20 g/L iodide and 4 g/L iodine to extract gold from oxide gold ores, and the gold extraction rate reached up to 89% in 24 h. On the contrary, when sodium iodate was used as an oxidant, gold could not be extracted in 48 h. Gold leaching began when hydrochloric acid was added to the iodate solution …
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adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A
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Gold leaching from ore using iodide-iodine mixtures is an alternative to gold cyanidation. This study evaluated the ability of iodide …
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Abstract Since the birth of cyanidation, it has been dominant in the gold extraction industry. Recently, with the increasing awareness of environmental hazards …
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In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 77% in 6 h and 89% in 24 h. With iodate as the oxidant, no gold could be leached in ...
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Gold is recoverable from leach solutions by conventional adsorption onto activated carbon. 1. Introduction Cyanide has been used for gold extraction for over 100 years and is the default lixiviant in the gold industry. It is cheap and effective for gold dissolution, producing a highly stable gold-cyanide complex which is
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Effect of pH on gold extraction from gold oxide ore by Glyleach™ process at leach conditions of 15 g/L glycine, 30% solid content, −75 µm, pH, and 55 °C. ... A fundamental rotating disk study of gold dissolution in iodine-iodide solutions. Hydrometallurgy, 34 (1) (1993), pp. 49-64. View PDF View article View in Scopus Google …
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Ore Classification. The efficiency and recovery of chemical processes involved in gold extraction is exclusive to the mineralogy of the ore. Gold may exist as free nuggets or particles in alluvial or elluvial deposits or as native metal in other minerals. The gold mineralogy of any given ore deposit is unique to all others due to variations in ...
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adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A
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The extraction of metals and their isolation occurs over a few major steps: Concentration of Ore – Here the ore is separated from earthy impurities. Isolation of metal from concentrated Ore – Here the ore is converted to its oxide form and then reduced. The steps involved are either calcination or roasting and then heating with a reducing ...
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Production of iodine from caliche ore is a two-step process: 1. Extraction of iodate solutions from the caliche ore. 2. Reduction of iodate to iodine. Iodate can be extracted from ore by leaching in one of two ways depending on the ore's nitrate concentration: Most of the iodate solution from leaching goes through a sulfur oxide …
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Platinum extraction using iodine/iodide solutions seems more promising than the other halogen systems. The standard redox potentials of Pt 4+, ... Leaching of an oxide gold ore with chloride/hypochlorite solutions. International Journal of Mineral Processing (2007) Baghalha M. et al.
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The extraction of gold from ores by biosynthesized reagents is discussed. • The use of cyanogenic bacteria for extracting gold is reviewed and discussed. • The …
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Leaching of an oxide gold ore with chloride/hypochlorite solutions. Int. J. Miner. ... (Li et al., 2021), acetonitrile/methylene dichloride (Chen et al., 2021), 2-mercaptobenzimidazole/iodine (Zupanc et al., 2022) and synthetic lixiviants (Guo et al., 2022; Zhang et al., 2022a, 2022b). ... Gold extraction from ore to solution throughout …
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In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 77% in 6 h and 89% in 24 h. With iodate as the …
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