Thiosulfate leaching in carbonaceous gold-bearing ores in …

One of the main unit operations in metallurgical processing plant designs is gold leaching. The traditional cyanidation process was chosen and is currently in widespread use. However, the mining ...

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Review A systematic review of gold extraction: Fundamentals

The total content of cyanide in typical cyanide tailings is much higher than the limit of toxicity characteristic leaching procedure (TCLP), which requires a further detoxification process. ... Although a series of studies on gold leaching with sulfur-containing lixiviants have been carried out since the 1970 s, the current influence is still ...

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The effect of sulfide minerals on the leaching of gold in aerated

The formation of a monolayer of sulfur on gold in alkaline non-cyanide solutions has also been noted by others (Briceno and Chandler, 1990, ... It has been shown that gold leaching in cyanide solutions is severely hindered by the presence of chalcocite due to the high solubility of this mineral in cyanide solutions. The gold leaching rate in ...

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Predicting Cyanide Consumption in Gold Leaching: A …

This paper proposes a robust methodology to estimate leaching cyanide consumption due to oxidation and reactions with gold, chalcopyrite and pyrite minerals forming various cyanide complexes,...

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Recovery of gold from sulfide refractory gold ore: Oxidation …

Most of the gold in the roasting slag is recovered by thiourea/cyanide leaching process, however, the leaching residues (gold tailings) obtained from thiourea leaching process or the sodium cyanide leaching still contain 9–16 g/t gold, which is difficult to recover and is usually discarded with the leaching residues; This phenomenon is common ...

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A fundamental study of the alkaline sulfide leaching of gold

from a solution containing 0.02M potassium dicyanoaurate, 0.23M potassium cyanide, 0.086M potassium carbonate. The gold/silver alloy was prepared by the same procedure, with the exception that 0.5mM silver ... Kinetic plot showing the mass of the electrode during the leaching of gold/silver in a caustic sulfur solution at 60°C. Also shown is ...

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Remediation of reduced sulfur species effects on gold and silver

Cyanidation circuits that treat sulfidic ores may contain one or more of the following reduced sulfur species: sulfide (HS −), polysulfides (S n 2−), thiocyanate (SCN −), thiosulfate (S 2 O 3 2−), trithionate (S 3 O 6 2−), tetrathionate (S 4 O 6 2−), pentathionate (S 5 O 6 2−), hexathionate (S 6 O 6 2−).The actual speciation of the reduced sulfur species in the circuits will ...

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Cyanide leaching of gold in solutions containing sulfide

On that matter, elemental sulfur and sulfides have been described as the most deleterious sulfur species during cyanide leaching. Sulfide minerals are known to cause the following effects: (1 ...

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Technology for Aiding the Cyanide Leaching of Gold Ores

Cyanide leaching technology was studied for low-grade oxidized gold ores in Guangxi Province. The gold grade of the raw ores was 1.32 g/t. The gold leaching rate was 90.91% under the optimal conditions for the following conventional leaching process: using steel forging as the grinding medium, a grinding fineness of −0.074 mm accounting for 92.53%, a …

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(PDF) Leaching of gold ores with high cyanicides: a

Processing of gold ores with high sulfide minerals is problematic as they consume cyanide and reduce gold leaching. Optimization of gold leaching and cyanide consumption requires a methodology to ...

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A Review of the Cyanidation Treatment of Copper-Gold Ores and …

Globally, copper, silver, and gold orebody grades have been dropping, and the mineralogy surrounding them has become more diversified and complex. The cyanidation process for gold production has remained dominant for over 130 years because of its selectivity and feasibility in the mining industry. For this reason, the industry has been adjusting its methods …

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Remediation of reduced sulfur species effects on gold and silver

Download Citation | Remediation of reduced sulfur species effects on gold and silver recovery during cyanide leaching | Cyanidation circuits that treat sulfidic ores may contain one or more of the ...

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Cyanide Leaching Chemistry & Gold Cyanidation

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

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(PDF) Alternatives to cyanide in the gold mining …

This paper reviews a series of alternative lixiviant systems for the recovery of gold from ores and concentrates. For over 100 years, cyanide has been the leach reagent of choice in gold mining ...

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Oxidation Behaviour and Bio-oxidation of Gold-bearing …

limitations are found to affect the rate of sulphide oxidation and the volume of materials that can be treated for gold leaching. ... which generally limits the oxidative gold dissolution rates (Mpinga et al., 2015 ... ores is the destabilisation of gold cyanide complex by sulphur metastable species such as hydrosulphide, polysulphide ...

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(PDF) Evaluation of pre-treatment methods for gold recovery from

The cyanidation results showed that the cyanide gold leaching rate of acid leaching residues was close to 100wt%. However, the maximum cyanide gold leaching rate of gold calcine was only 85.31wt%.

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A review of gold extraction using alternatives to cyanide: Focus …

The substitutes for cyanide can be classified as traditional and novel non-cyanide gold leaching reagents. The traditional alternatives mainly include thiourea, halide, polysulfide, thiocyanate, lime sulfur synthetic solution (LSSS), and thiosulfate (Hilson and Monhemius, 2006, Sun et al., 2020, Xing et al., 2019).Although considerable investigations into gold extraction …

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Optimization of microwave-assisted roasting: Box-behnken …

Using highly hazardous chemicals impedes leaching and poses a significant risk to human health and the ecosystem [19].In addition, the presence of impurity metals in RGO, such as copper, zinc, and nickel, increases the need for oxidants and cyanide, which forms a coating on the gold surface, impedes the leaching, and reducing the rate of gold recovery [19, 20].

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Gold Metallurgy & Leaching in Cyanicides

Here is a list of methods to help you on how to manage gold leaching when cyanide consumers are present. Recovering Gold from Iron Sulphides While the oxidized iron minerals …

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Arsenic and Antimony Sulphide Minerals in Cyanidation

Orpiment was detrimental to gold leaching, the retardation becoming more pronounced as pH increased. The extractions in 48 hours at pH 10, 11, and 12 were 73, 44, and 19%, respectively, as compared with over 95% in the case of the control tests. ... the realgar 0.0035%, and the stibnite 0.007% total sulphide sulphur. Multiple cyanidation tests ...

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The role of metal-cyanide species in leaching gold from a copper

It would only be necessary to add an excess of cyanide to the beginning of the carbon adsorption circuit in order to limit adsorption of divalent copper-cyanide species to the carbon surface. In well oxygenated solutions, all the cyanide that is not lost to hydrolysis, oxidation or reaction with sulphur could be used indirectly for gold ...

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Oxidative leaching of refractory sulphidic gold tailings with an ionic

The effect of temperature in the range of 20–65 °C on gold extraction from refractory gold tailings containing pyrite in 20% (v/v) of 1-butyl-3-methylimidazolium hydrogen sulphate [Bmim + HSO 4 −]-water solution with thiourea as complexing agent and iron(III) sulphate oxidant, at pH of 1 was examined for 12 h leaching time intervals.The experimental results revealed …

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Resource Utilization of Iron and Gold from Roasted Cyanide …

This study uses sulfuric acid activation-water leaching method to decompose and leach iron from roasted cyanide tailings, thereby creating favorable conditions for the further leaching of gold from the tailings. The leachate obtained from the decomposition of iron is purified and then prepared into liquid polyferric sulfate. The gold in the leaching residue after iron …

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New Technology for Recovery of Gold and Silver by Pressure Cyanidation

In the following a brief description of used leaching reagents takes place 8-11. Cyanide and Alternative Gold Leaching Reagents The most commonly used cyanide salts are KCN and NaCN, which are easily soluble in water. Cyanide leaching is the dominating process for gold recovery from primary resources, due to its simplicity and high cost efficiency.

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The Ultimate Guide to Gold Cyanidation

The gold-containing sulfur concentrate is concentrated and decontaminated by a thickener and a filter, and is subjected to two-stage grinding to 98% -0.044 mm, and then carried out continuous cyanidation leaching in …

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MERCURY CONTROL IN THE CYANIDATION OF GOLD …

Salt Lake City, Utah have reported on mercury precipitation from gold cyanide leach solutions with caS and Na2S. They found that Na2S and CaS can serve as ... Electrochemical phase diagram for the mercury-sulfur-water system at 25°C. (Total dissolved sulfur = 8.6x1O-5 M, total dissolved mercury = 4.3x1O-5M)

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Effects of pyrite, quartz and sodium sulfite on roasting of a

Complex refractory gold ores, which have become a major raw material for global gold production (Bas et al., 2017), generally contain gold, silver, copper, sulfur and other valuable elements.The complex properties, many cyanide-consuming substances (Deschenes et al., 2000), and gold particles of fine size range (Bas et al., 2018) lead to poor conventional …

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The Ultimate Guide to Gold Cyanidation

The gold-containing sulfur concentrate is leached by a agitation leaching system. The gold-containing sulfur concentrate is concentrated and decontaminated by a thickener and a filter, and is subjected to two-stage grinding to 98% -0.044 mm, and then carried out continuous cyanidation leaching in four mechanical agitation leaching tanks (φ3500 ...

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Arsenic and Antimony Sulphide Minerals in Cyanidation

The successful cyanidation of gold ores containing appreciable amounts of arsenic or antimony sulphide minerals such as orpiment, realgar, …

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A review of gold extraction using noncyanide lixiviants: …

Alkaline sulfur-containing lixiviants, including thiosulfate, polysulfides, and alkaline sulfide solutions, stand out as a promising class of alternatives to cyanide because of their low toxicity, high efficiency, and strong adaptability. In this paper, we summarized the research progress and remaining challenges in gold extraction using these noncyanide reagents. After a …

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