2000-9-1 Such a finding suggests that in this instance lead hinders the Cyanide leaching of gold in solutions containing sulfide 1105 leaching reaction. It is believed that in the presence of hydrosulfide ions, the lead present on the gold surface is oxidised to form PbS (Eof this reaction is
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Since the sulfide minerals are to some extent soluble in cyanide solutions, there will always be some sulfur species present in the leach solution. It has been shown that soluble sulfide hinders the rate of gold leaching, forming a protective layer of the type Au/S x. Electrochemical studies of the constituent half reactions: gold oxidation ...
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2020-6-11 A large proportion of the gold processed in the 21"' century will be recovered from sulfide ores. Since the sulfide minerals are to some extent soluble in cyanide solutions, there will always be some sulfur species present in the leach solution. It has been shown that soluble sulfide hinders the rate of gold leaching, forming a protective layer of the type AulSx. Electrochemical studies of the ...
More2006-8-1 The oxidation of gold and some sulfide minerals in solutions containing 5 mmol L − 1 cyanide and 50 mmol L − 1 sodium perchlorate as background electrolyte was studied using linear sweep voltammetry, and the polarization curves are shown in Fig. 1.It can be seen that gold oxidation commences at − 620 mV and approaches a diffusion limited current of 15 A m − 2 at 0 mV.
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2020-6-10 JEFFREY M I, BREUER P L. The cyanide leaching of gold in solutions containing sulfide [J]. Minerals Engineering, 2000, 13(10): 1097–1106. Doi: 10.1016/S0892-6875(00)00093-5. Article Google Scholar [21] LORENZEN L, DEVENTER J S J V
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2015-12-27 this provides a simple way of producing a concentrated gold sample prior to leaching. It has also shown that gold can be selectively recovered from complex alkaline sulfide solutions containing a mixture of metals such as arsenic, tin, mercury and antimony. These studies showed that almost 100% of the gold
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2018-9-5 Gold ore having 17 ppm mercury was leached with solutions containing 0.34 and 8 lb NaCN per ton of solution and lime, and then contacted with Na2S. The results of these tests are shown in figure 7. Increasing Na2S lowered mercury extraction when
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2020-4-14 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.
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2005-8-1 However, when leaching chalcocite in Cu(CN) 3 2− solutions, little sulfide was dissolved and gold leaching was found to be more rapid than for the free cyanide solution. Preliminary test work with gold ore samples containing CuO indicated that the initial kinetics of gold dissolution in air saturated Cu(CN) 3 2− solutions were comparable to ...
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2015-2-6 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
More2020-6-11 A large proportion of the gold processed in the 21"' century will be recovered from sulfide ores. Since the sulfide minerals are to some extent soluble in cyanide solutions, there will always be some sulfur species present in the leach solution. It has been shown that soluble sulfide hinders the rate of gold leaching, forming a protective layer of the type AulSx. Electrochemical studies of the ...
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Cyanide leaching of gold in solutions containing sulfide The effect of sulfide minerals on the leaching of gold in aerated cyanide solutions this reaction occurs is known as the Elsner 1846 equation Jeffrey 2000 : . Effect of hydrogen peroxide and lead II nitrate on gold 21 Aug 2020 Cyanide lixiviant has been used as a leaching medium in the ...
More2018-9-5 Gold ore having 17 ppm mercury was leached with solutions containing 0.34 and 8 lb NaCN per ton of solution and lime, and then contacted with Na2S. The results of these tests are shown in figure 7. Increasing Na2S lowered mercury extraction when low concentrations of cyanide (0.34 lb NaCN per ton of solution) were used.
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Cyanide leaching of the concentrate was performed at 20%-w/w of solid 500 gram ofrefractory sulfide gold ore concentrate in a 2.5-liter glass reactor with aeration andstirred at 250 rpm. Leach solutions were prepared using deionized-distilled water at the
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2020-6-4 decrease the leaching rate of gold [12, 13]. This is because most copper minerals are greatly soluble in cyanide solutions [14], and their dissolution consumes large amounts of cyanide and oxygen [15−17], thus reducing the concentration of the free
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2009-8-19 sulfide solutions be recovered. As shown in Figure 3, gold is soluble in the alkaline sulfide system. Gold lixiviation is the result of leaching by polysulfides and sulfides as shown in equation 8. 2Au + S2 2-+ 2S2- 2AuS-+2S2-(8) Figure 3. Equilibrium Species Eh-pH Diagram for Sulfur and Alkaline Sulfide Gold
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Gold is mainly extracted from its ores or concentrates by leaching with oxygenated cyanide solutions [1,2].Cyanide consumption during leaching, and the discharge of excess cyanide in wastewater, respectively constitute major economic [3,4] and environmental [] costs in the gold industry.Cyanide losses in the leaching stage mainly occur via the action of “cyanicides”: minerals, such as the ...
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2016-8-18 By cyanide leaching besides gold also other heavy metals like arsenic, nickel, cadmium, cobalt, copper and mercury can be extracted from gold resources and these dissolved metals have crucial impacts on environment as well [18] . In areas near gold leaching industry cyanide can pass soil and even contaminate the underground water.
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2012-10-4 Chloride–hypochlorite oxidation and leaching of refractory sulfide gold concentrate 63 Fig. 1. The Pourbaix diagram of Fe–S at [Fe] –= 10 4 M, [S] = 10– M and 25 C (the chlorine species regions are also marked) (Marsden and House, 2005) Fig. 2.
MoreThe cyanide content of 50 ppm by weight is then established with cyanide-containing wastewater. Column Experiments: Column experiments in which representative samples of the gold-containing rock are packed in columns and leached with alkaline cyanide solutions serve as a model of the heap leaching carried out industrially.
More2020-6-11 A large proportion of the gold processed in the 21"' century will be recovered from sulfide ores. Since the sulfide minerals are to some extent soluble in cyanide solutions, there will always be some sulfur species present in the leach solution. It has been shown that soluble sulfide hinders the rate of gold leaching, forming a protective layer of the type AulSx. Electrochemical studies of the ...
MoreCyanide leaching of gold in solutions containing sulfide The effect of sulfide minerals on the leaching of gold in aerated cyanide solutions this reaction occurs is known as the Elsner 1846 equation Jeffrey 2000 : . Effect of hydrogen peroxide and lead II nitrate on gold 21 Aug 2020 Cyanide lixiviant has been used as a leaching medium in the ...
MoreCyanide leaching of the concentrate was performed at 20%-w/w of solid 500 gram ofrefractory sulfide gold ore concentrate in a 2.5-liter glass reactor with aeration andstirred at 250 rpm. Leach solutions were prepared using deionized-distilled water at the
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SUBSTANCE: method includes grinding of initial material, cyanide leaching with production of a product solution of gold with mercury admixtures, introduction of a sulfide-containing reagent for mercury deposition, sorption of gold onto activated coal with return of the reuse cyanide solution for leaching, desorption of gold and electrolysis of ...
More2020-6-4 decrease the leaching rate of gold [12, 13]. This is because most copper minerals are greatly soluble in cyanide solutions [14], and their dissolution consumes large amounts of cyanide and oxygen [15−17], thus reducing the concentration of the free
More2009-8-19 sulfide solutions be recovered. As shown in Figure 3, gold is soluble in the alkaline sulfide system. Gold lixiviation is the result of leaching by polysulfides and sulfides as shown in equation 8. 2Au + S2 2-+ 2S2- 2AuS-+2S2-(8) Figure 3. Equilibrium Species Eh-pH Diagram for Sulfur and Alkaline Sulfide Gold
More2016-8-18 By cyanide leaching besides gold also other heavy metals like arsenic, nickel, cadmium, cobalt, copper and mercury can be extracted from gold resources and these dissolved metals have crucial impacts on environment as well [18] . In areas near gold leaching industry cyanide can pass soil and even contaminate the underground water.
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gold cyanide solutions (i-2). Silver sulfide would tie up considerable silver, and iron sulfide forms ferrocyanide, re sulting in cYanide loss. Calcium and so dium sulfides are effective in precipi tating mercury and are not harmful to the gold recovery process. Redissolution of mercury occurs when sodium sulfide is
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The present invention relates to solutions comprising water and at least one metal cyanide, at least a part of the water being obtained from wastewater which occurs as depleted wastewater in a process for extracting noble metals from noble metal-containing ores by the cyanide process, the process for the preparation of solutions according to the invention and to the use of the solutions ...
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2018-12-14 for the analysis of cyanide in solutions containing 50-100 ppm free cyanide. Furthermore, 0.000125 mol/liter silver nitrate is the most suitable concentration of the titrant in solutions containing 1-10 ppm free cyanide. Finally, the data were applied for the determination of free cyanide concentration in a synthetic mine water.
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2013-1-3 Leaching gold from sulfide ores is difficult, at best. Generally, the recovery for cyanide leaching of sulfide or refractory ores is no better than 30%, which is not a worthwhile venture. The use of alkalies such as calcium oxide, will prevent the decomposition of cyanide in solution to form hydrogen cyanide
MoreCyanide leaching of the concentrate was performed at 20%-w/w of solid 500 gram ofrefractory sulfide gold ore concentrate in a 2.5-liter glass reactor with aeration andstirred at 250 rpm. Leach solutions were prepared using deionized-distilled water at the
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2019-10-18 The agitation leaching method is to concentrate the slurry, obtained after grinding and classifying of the gold-containing ore, to a suitable concentration, place it in a leaching tank, add a cyanide solution, and aerate to carry out leaching. The main equipment used in the agitation leaching process is a cyanide leaching tank.
MoreSUBSTANCE: method includes grinding of initial material, cyanide leaching with production of a product solution of gold with mercury admixtures, introduction of a sulfide-containing reagent for mercury deposition, sorption of gold onto activated coal with return of the reuse cyanide solution for leaching, desorption of gold and electrolysis of ...
More2020-6-4 decrease the leaching rate of gold [12, 13]. This is because most copper minerals are greatly soluble in cyanide solutions [14], and their dissolution consumes large amounts of cyanide and oxygen [15−17], thus reducing the concentration of the free
More2009-8-19 sulfide solutions be recovered. As shown in Figure 3, gold is soluble in the alkaline sulfide system. Gold lixiviation is the result of leaching by polysulfides and sulfides as shown in equation 8. 2Au + S2 2-+ 2S2- 2AuS-+2S2-(8) Figure 3. Equilibrium Species Eh-pH Diagram for Sulfur and Alkaline Sulfide Gold
Moregold cyanide solutions (i-2). Silver sulfide would tie up considerable silver, and iron sulfide forms ferrocyanide, re sulting in cYanide loss. Calcium and so dium sulfides are effective in precipi tating mercury and are not harmful to the gold recovery process. Redissolution of mercury occurs when sodium sulfide is
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Leaching of gold and silver from printed circuit board of mobile phones. The commercial leachate used for comparison purposes was a chemical leacher (Galvastripper®) for gold and its alloys. This product is supplied as a liquid containing potassium cyanide in a concentration of 6 to 8%, slightly yellow, and removes up to 1 mm gold.
More2018-12-14 for the analysis of cyanide in solutions containing 50-100 ppm free cyanide. Furthermore, 0.000125 mol/liter silver nitrate is the most suitable concentration of the titrant in solutions containing 1-10 ppm free cyanide. Finally, the data were applied for the determination of free cyanide concentration in a synthetic mine water.
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2020-2-24 leaching rate but also increase the consumption of thiosulfate. Comparable gold extractions were observed in the leaching of the composite ores containing various sulfide minerals, such as pyrite, pyrrhotite, chalcocite, galena and chalcopyrite. The leaching of gold in the presence of iron sulfides was also improved by
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