gold leaching polysulfide

Mining - TKINet

Thio-Gold is a non-toxic alternative to the use of cyanide in precious metal leaching. TKI-330 | PROPRIETARY Polysulfide-BASED Solution TKI-330 is a non-hazardous liquid used in various waste treatment applications as a metal precipitant.

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Biodetoxification of Heavy Metals Using Biofilm Bacteria

The dissolution chemistry of metal sulfides follows two pathways, which are determined by the mineralogy and the acid solubility of the metal sulfides: the thiosulfate and the polysulfide pathways.

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Behavior of S and SO in sulfur-bearing aqueous solution ...

reagents leaching gold for the environmental issues. Up to now, the main non-cyanide processes include thiosulfate, polysulfide, LSSS (lime sulfur synthetic solution), ML (modified LSSS), thiocyanate, chloride, and bromide leaching processes etc[1−7]. Many processes and mechanisms of leaching gold system were studied in China. Research works on

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A mechanism of metastable sulfur speciation and the ...

During the cyanide leaching of sulfidic gold ores, the sulfide minerals dissolve into the leach solution and produce metastable sulfur species, such as sulfide, bisulfide, polysulfide, elemental sulfur, and thiocyanate. Most of the above sulfur species can directly passivate the gold surface, and significantly reduce the gold leaching efficiency.

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(PDF) Thiosulfate leaching of gold—A review | Mark Aylmore ...

Hemmati et al. (1989) investigated the thiosulfate leaching of gold from carbonaceous ore that contained 2.5% organic carbon. The optimum conditions for gold extraction were found to be 35°C and 103 kPa oxygen over pressure, pH 10.5, 3M NH3 with a lixiviant containing 0.71M (NH4)2S203, 0.15M CuSO4 and 0.1M (NH4)2SO3.

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Frontiers | Selective Pre-leaching of Tellurium From ...

Mar 25, 2021· This process first concentrates telluride-type gold ore, then follows by oxidative roasting, cyanide leaching, polysulfide leaching, sodium sulfite reduction, and other processes to recover tellurium and gold (Zhou and Chen, 2008). This method has a complicated process and high investment cost, and is difficult to apply to other processing plants.

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Extracting Gold | HowStuffWorks

Finally, the gold-bearing solution is ready for electrowinning, which recovers the gold from the leaching chemicals. In electrowinning, operators pour the gold-bearing solution into a special container known as a cell. Positive and negative terminals in the cell deliver a strong electric current to the solution. This causes gold to collect on ...

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Basic theory and optimization of gold containing antimony ...

Through leaching test and kinetics analysis, the decomposition regularity of sodium sulfide and leaching rate were studied under different leaching conditions. The results indicated that the gold content in antimony concentrate was 28.41g/Mg, and the content of …

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A fundamental study of the alkaline sulfide leaching of gold

solution also contains polysulfide, it is likely that this species is the oxidant for gold leaching. The potential of the sulfide / polysulfide system can be conveniently represented by an E-pH diagram. A metastable E-pH diagram for sulfur in alkaline solutions was generated using the StabCal thermochemistry package (Huang

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How to Use Bleach on Gold Ore to Remove Gold | Sciencing

Apr 24, 2017· How to Leach Gold Ore With Chlorination. Updated April 24, 2017. By Maria Kielmas. Gold is an almost non-reactive metal, but halogens — chlorine, bromine, fluorine and iodine — can dissolve it. Chlorine is the cheapest and lightest product that can achieve this. Bleach is the chemical compound sodium hypochlorite.

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Micromechanism Study of Strengthening Effect of Copper on ...

To study the effect of copper on gold thiosulfate leaching, the gold dissolution of three different sample powders (gold, gold/copper, and gold/copper oxide) in a solution of 5 mM Cu2+, 0.4 M ammonia, and 0.1 M thiosulfate was studied. Scanning electron microscopy analysis showed no sulfur passivation on the gold surface, and there were more prominent corrosion pits on the gold surfaces of ...

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Solvent extraction of gold from polysulfide solution

Study on the leaching of gold with polysulfide. Gold 3, 33-37. Cu of Au(I) Extraction from gold-containing noble solution by N 1923 /n-octane and N 1923 -TBP/n-octane pH β Au

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(PDF) ALKALINE SULFIDE RECOVERY OF GOLD UTILIZING …

The actual leaching occurring in the polysulfide and bisulfide system may be attributable to the presence of some sulfide in equilibrium with the bisulfide and polysulfide. ... Table IX.-Alkaline Sulfide Gold Leach Head Solution Assay Volume L Au Sb As Hg Sn 0.5 88.7 ppm 21.0 g/L 5.31 g/L 274 ppm 1.84 g/L Table X.-Alkaline Sulfide Gold Solution ...

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Alkaline Sulfide Gold Leaching Kinetics - ResearchGate

Gold lixiviation is the result of leaching by polysulfides and sulfides as shown in equation 8. (Anderson, 2001a; Jeffrey & Anderson, 2002; Anderson, et al, 2004; Anderson, et al. 2005). 2Au + S 2

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Patents Assigned to Barrick Gold Corporation - Justia ...

Jan 29, 2020· Abstract: A method to recover gold lost in roaster calcine-leach tailings, due to the formation of cyanide refractory compounds or morphologies during the roasting process. The process can include acid leaching of magnetic concentrate from roaster leach tailings, combining the acid leach slurry to the pre-acidulation tank for pressure oxidation ...

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Thiosulfate Leaching Of Gold – A Review: Mark G Aylmore ...

LEACHING WITH POLYSULFIDE In addition to thiosulfate, polysulfides will also be present during leaching. These can be produced from the disproportionation of elemental sulfur or thiosulfate decomposition. Investigations into the use of polysulfides to leach gold has been carried out by …

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Shell‐isolated nanoparticle‐enhanced Raman spectroscopy ...

Aug 11, 2016· The SHINERS spectra revealed that the passive layer at the untreated oxide ore–electrolyte interface contains metal sulfides and significant quantities of polysulfide chains of variable lengths after longer exposure to the leaching solution. However, the passive layer observed with the POX-treated sample was found to be predominantly metal ...

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CN103290232A - Method for extracting gold from auriferous ...

The invention relates to a method for extracting gold through potassium ferricyanide. The method is characterized in that the gold is extracted from the auriferous ores under an alkaline environment at normal temperature and pressure with nontoxic ferricyanide serving as a gold leaching agent and calcium peroxide serving as a leaching adding agent; and the method is a completely novel cyanide ...

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THE ALKALINE SULFIDE HYDROMETALLURGICAL SEPARATION ...

2.2 Selective Recovery of Gold from Alkaline Sulfide Solutions In the example cited above, it is essential in that any gold leached in the alkaline 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.

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Connection between gold dissolution in thiosulfate ...

Dec 20, 2019· Moreover, copper polysulfide was detected as the passive layer on the gold surface at high potential under conventional leaching conditions . Additionally, ammonia and copper were adsorbed onto the gold surface to form the passivation layer under typical leaching conditions [ 14 ].

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Application of Polysulfide for Pretreatment of Spent ...

Calcium polysulfide converts waste cyanides to thiocyanates and precipitates metals to levels generally within sewer use ordinances. Further unpublished experiments by the authors were per formed on cyanide-containing wastewaters from a gold leaching process. A cyanide-to-polysulfide …

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Mercury control in the cyanidation of gold ores

leaching and follows gold through the solution concentration and puriflcation step (carbon adsorption and electrowinning or zinc cementation). Ultimately, prior to the ... of thiol groups and polysulfide links which might reasonably be expected to provide sites for …

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Method for thiosulfate leaching of precious metal ...

The gold extraction peaked at approximately 83%, the maximum extractable, after 6 hours leaching. Gold leaching was slowed if the temperature was lowered to 40° C., but 80% gold extraction was still obtained after 10 hours leaching at 40° C. An overall summary of the results is provided below:

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Permeation & Leaching - US EPA

leaching and permeation of organic contaminants and other metals. 1.1 Permeation of Piping and Non-Metallic Joints Permeation is a physicochemical mass transfer phenomenon involving diffusion of a solute through a porous medium. The driving force for mass transfer is the presence of an activity (e.g.,

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Alkaline Sulfide Recovery of Gold | Sulfide | Sulfur

The actual leaching occurring in the polysulfide and bisulfide system may be attributable to the presence of some sulfide in equilibrium with the bisulfide and polysulfide. A number of ligands form stable compound with the aurous cations, including sulfide and bisulfide.

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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.

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CN104805281A - Method for leaching sulfide gold ...

The invention relates to a method for leaching sulfide gold concentrate by virtue of combination of acid pressure leaching and alkali pressure leaching. The method comprises an acid pressure leaching pretreatment stage and an alkali pressure leaching stage; firstly, in an acid pressure leaching process, reaction conditions are controlled, so that sulfides are oxidized, part of elemental sulfur ...

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(PDF) Alkaline Sulfide Gold Leaching Kinetics

The sulfide / polysulfide system, while known to leach gold, has received very little. fundamental research. The occurrence of electr ochemical reactions other than those.

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