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experiments for the effect of ph on gold leaching

Leaching and CIL processes in gold recovery from ...

2007-5-1  The effect of pH on gold recovery was investigated for the pH values of 1.0; 1.5; 2.0 and 2.5 since it was defined in literature that thiourea could be decomposed readily at high pH values and Fe 3+ used as oxidizing agent might be precipitated as Fe(OH) 3 by hydrolysis at the pH values greater than 3–3.5 (Smith and Mudder, 1991, Li and ...

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Experimental Study on the Leaching of Gold from ...

1993-6-1  Abstract Experiments were conducted on the leaching of gold from greenstone by chloride solution under the temperature of 200‐550°C and the pressure of 60 MPa. During part of the experiments, the oxygen fugacity was controlled. The results show that the leaching rate of gold is related to temperature, composition of the solution, pH and oxygen fugacity. In the experiment with oxidative ...

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Effect of mixing acidic and alkaline pressure oxidation ...

Hydrometallurgy leaching experiments carried out on alkaline and acidic POX discharge ores to get the gold recovery. ... pH of the slurry becomes about 4 and then it is adjusted to 8 by lime addition to the slurry. ... This study focuses on different mixing ratios of the two acidic and alkaline POX discharges and its effect on gold leaching ...

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Adsorption of gold from cyanide leaching solution onto ...

2017-10-25  Activated carbon experiments. First, the cyanidation (cyanide leaching) experiments were carried out in a tumble bottle under optimal condition of Sarigoni (Qorveh) gold processing plant at ambient temperature, pH of 11, liquid to solid ratio of 2, sodium cyanide concentration of 1 g/L, particle size finer than 74 μm and leaching time of 24 h.For each test, a 300 g representative sample was ...

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Ammoniacal thiosulphate leaching of gold ore

2016-6-2  leaching were restricted for about 5h for the rest of the leaching experiments. Figure 1. Ammoniacal thiosulphate leaching of Akeshi and Hishikari gold ores a) as a function of time and b) as a function of pH and E h (Thiosulphate concentration, 0.5M; Ammonia concentration, 1M) 3.2. Effect of

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How Maintain pH on Leaching Tank - Hydrometallurgy ...

2021-10-31  Any idea to maintain pH on leaching tank that is relatively high (chemical reagent added will not give negative effect on leaching performance)?Our plant is having problem with high pH of leaching. Based on our lab test, optimum pH is on range 10.3-10.8. But, recently the pH

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The adsorption of gold on activated carbon from ...

2017-8-29  Previous investigations on gold leaching confirmed that a pH value of near 9.5 was optimal for gold extraction [1,2,11]; therefore, the effect of pH on gold adsorption was studied in this range. As can be seen from the results shown in Table 3, the pH variation did affect the gold adsorption, i.e., it was severely retarded at the lower and ...

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Thiocyanate hydrometallurgy for the recovery of gold ...

2012-2-1  The effect of thiocyanate concentration on the rate of gold leaching was examined in the thiocyanate concentration range of 0.05–0.2 M.The results are presented in Fig. 2.It is understood from Fig. 2 that the initial rate of gold leaching is quite slow and most interestingly, almost insensitive to thiocyanate concentration (0.05–0.2 M). The rate decreases with an increase in the leaching time.

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Effect of pH on Cyanidation Process - Hydrometallurgy ...

2021-11-2  Running your CIL at a lower pH the causes the reaction to be more thorough rather than faster at lower pH conditions. What this means is- The lower pH may increase the number of free CN- ions and therefore as the concentration of dissolved CN ions is the main driver of dissolution rate of gold then the lower pH stands to drive the reaction faster or more thoroughly.

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Experimental Study on the Leaching of Gold from ...

1993-6-1  Abstract Experiments were conducted on the leaching of gold from greenstone by chloride solution under the temperature of 200‐550°C and the pressure of 60 MPa. During part of the experiments, the oxygen fugacity was controlled. The results show that the leaching rate of gold is related to temperature, composition of the solution, pH and oxygen fugacity. In the experiment with oxidative ...

More

Decomposition of Cyanide from Gold Leaching Tailingsby ...

3.2. Effect of pH on the Decomposition of Cyanide by H 2 O 2. The pH value had a significant effect on cyanide removal [21, 27].The tailings were treated with 0.5 g/L Na 2 S 2 O 5 for 3 hours at pH 10, and then individual experiments were carried out at pH values ranging from 8 to 11. Figures 2(a)–2(c) show the effect of equilibrium pH on the cyanide of lixiviant of tailings after Na 2 S 2 O ...

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Ammoniacal thiosulphate leaching of gold ore

2016-6-2  leaching were restricted for about 5h for the rest of the leaching experiments. Figure 1. Ammoniacal thiosulphate leaching of Akeshi and Hishikari gold ores a) as a function of time and b) as a function of pH and E h (Thiosulphate concentration, 0.5M; Ammonia concentration, 1M) 3.2. Effect of

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The Grinding Fineness- the Factor Affecting Gold Leaching

2020-3-25  Cyanide leaching process is one of the common gold ore beneficiation processes. The process index depends on factors such as gold particle size, sulfide content, ore block size, leaching speed, leaching time, cyanide concentration and leaching slag washing degree. The factors that affect gold leaching include grinding fineness, pH, temperature, cyanide dosage, pulp-solid-liquid ratio, leaching ...

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THIOCYANATE LEACHING OF GOLD - open.library.ubc.ca

2019-9-28  leaching, yielding gold extractions as high as 97% for Supremo composite 72142. A series of leaching tests were performed on the 72142 B sample with SCN-solutions to determine the feasible regions of gold dissolution and to maximize gold dissolution. The leaching tests were conducted in the acidic regime (pH 1.5 -2) for these samples.

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The Optimization of cyanidation for Hamze-Qarnein gold ore

2014-10-15  The acidic leaching using Thiourea, required more chemical reagents and maximum gold recovery of 90.48% was achieved with Thiourea consumption, leaching time, and pH

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FUNDAMENTAL ASPECTS OF GOLD LEACHING IN

2020-7-24  Anodic polarization, cathodic polarization and leaching experiments were included in this study. The effect of concentration of different reagents, ... Figure 2.3 Effect of thiosulfate concentration on the rest potential of gold(Li et al,1996). 6 Figure 2.4 Eh-pH diagram of the gold-thiosulfate-ammonia-water system at 25°C. ... Figure 2.27 The ...

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Cyanide Amenability Studies of Gold Ores-The Use of

2018-10-15  used as the pH modifier to raise the pH to 10.5 for each leaching test. After each leaching test, samples were taken, filtered and samples taken for free cyanide and Au analysis. The residues were thoroughly washed with water, dried, sampled and then fire assayed to determine the Au content. 2.3. Carbon-In-Leach Test (Cil)

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Analysis of Factors Affecting Heap Leaching Process of ...

2017-9-1  2.3 Effect of Clay Content in Ore on Heap Leaching Process. The clay content in the ore has obvious influence on the leaching of gold. When the clay is wetted by cyanide solution, its volume ...

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Decomposition of Cyanide from Gold Leaching Tailingsby ...

3.2. Effect of pH on the Decomposition of Cyanide by H 2 O 2. The pH value had a significant effect on cyanide removal [21, 27].The tailings were treated with 0.5 g/L Na 2 S 2 O 5 for 3 hours at pH 10, and then individual experiments were carried out at pH values ranging from 8 to 11. Figures 2(a)–2(c) show the effect of equilibrium pH on the cyanide of lixiviant of tailings after Na 2 S 2 O ...

More

Ammoniacal thiosulphate leaching of gold ore

2016-6-2  leaching were restricted for about 5h for the rest of the leaching experiments. Figure 1. Ammoniacal thiosulphate leaching of Akeshi and Hishikari gold ores a) as a function of time and b) as a function of pH and E h (Thiosulphate concentration, 0.5M; Ammonia concentration, 1M) 3.2. Effect of

More

The Optimization of cyanidation for Hamze-Qarnein gold ore

2014-10-15  The acidic leaching using Thiourea, required more chemical reagents and maximum gold recovery of 90.48% was achieved with Thiourea consumption, leaching time, and pH

More

THIOCYANATE LEACHING OF GOLD - open.library.ubc.ca

2019-9-28  leaching, yielding gold extractions as high as 97% for Supremo composite 72142. A series of leaching tests were performed on the 72142 B sample with SCN-solutions to determine the feasible regions of gold dissolution and to maximize gold dissolution. The leaching tests were conducted in the acidic regime (pH 1.5 -2) for these samples.

More

Cyanide Amenability Studies of Gold Ores-The Use of

2018-10-15  used as the pH modifier to raise the pH to 10.5 for each leaching test. After each leaching test, samples were taken, filtered and samples taken for free cyanide and Au analysis. The residues were thoroughly washed with water, dried, sampled and then fire assayed to determine the Au content. 2.3. Carbon-In-Leach Test (Cil)

More

Gold-leaching performance and mechanism of sodium

2021-4-27  Abstract: In this work, sodium dicyanamide (SD) was used as a leaching reagent for gold recovery, and the effects of the SD dosage and solu-tion pH on the gold-leaching performance were investigated. A gold recovery of 34.8% was obtained when SD was used as the sole leaching

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The process design of gold leaching and carbon-in-pulp ...

2009-8-27  Leaching reagents in the form of cyanide and an oxidant such as air or oxygen are added after thickening. Leaching takes place in a series of agitated leach reactors or pachucas. Before leaching the pH of the pulp is normally adjusted to a value of around 9.5–11 to ensure minimum loss of cyanide as hydrogen cyanide.

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FUNDAMENTAL ASPECTS OF GOLD LEACHING IN

2020-7-24  Anodic polarization, cathodic polarization and leaching experiments were included in this study. The effect of concentration of different reagents, ... Figure 2.3 Effect of thiosulfate concentration on the rest potential of gold(Li et al,1996). 6 Figure 2.4 Eh-pH diagram of the gold-thiosulfate-ammonia-water system at 25°C. ... Figure 2.27 The ...

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The Metallurgy of Cyanide Gold Leaching – An

2014-10-20  The Metallurgy of Cyanide Gold Leaching – An Introduction. Leaching gold with a cyanide solution remains the most widely used hydrometallurgical process for the extraction of gold from ores and concentrates. Despite the difficulties and hazards of

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Analysis of Factors Affecting Heap Leaching Process of ...

2017-9-1  2.3 Effect of Clay Content in Ore on Heap Leaching Process. The clay content in the ore has obvious influence on the leaching of gold. When the clay is wetted by cyanide solution, its volume ...

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