Oxidation of Refractory Gold Concentrates and
The oxidation of refractory arsenical gold concentrates in aerated alkaline solutions results in the formation of thiosulfate, arsenate and sulfate as well as the …Web
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Gold Extraction from Refractory Sulfide Gold Concentrates: A …
The effect of bio-oxidation and neutral atmospheric oxidation pre-treatment of refractory gold concentrates on gold and silver extraction during cyanidation was investigated. A series of pre-treatment experiments was conducted on three high sulfur (> 9%) refractory concentrates with 0.92–1.25 g/t gold and 64–90 g/t silver. Cyanidation of …Web
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Pressure Oxidation Overview
Acid and alkaline pressure oxidation of gold ores and concentrates are considered in terms of chemistry, process flowsheets, development history, materials of construction and other factors.Web
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Sulfuric Acid Baking—Water Leaching for Gold …
During the roasting of gold concentrate to improve gold recovery, arsenic is released into the air and valuable elements such as Fe, Cu, Zn, and Pb are converted into oxide minerals. In this research, we …Web
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Arsenic Pyrite Gold Extraction by Alkaline Leaching Oxidation
The alkaline oxidative leach pretreatment for gold-bearing arsenopyrite ores uses mild conditions, and the leach residue requires no washing or pH adjustment before cyanidation. By using 2M NaOH, 100° C, 40 psig O2, 10 pct solids, and 4 h, more than 90 pct of the arsenic was extracted from the high-grade ore.Web
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Pressure oxidation of arsenopyrite and pyrite in alkaline solutions
A number of trials on pressure alkaline oxidation of gold ores have been reported in the USSR [ 10-12 ]. One reports gold recoveries from 98.2 to 99.6% after cyanidation of the products ofautoclave oxidation in NaOH solutions, at 373-393 K [ l0 ]. The technique was tested with various concentrates assaying ! 8.9-621 g/t of gold.Web
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Non-cyanide Extraction of Gold from Carlin-Type Gold Concentrate …
Abstract Of late, given the difficulties in gold extraction and severe environmental pollution emanating from cyanide extraction of Carlin-type gold concentrate (CTGC), a novel pressure oxidation pretreatment followed by sodium jarosite decomposition and fine grinding was first proposed to extract gold from the CTGC in a …Web
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alkaline pressure oand idation of gold concentrates-About Alkaline …
Nov 30 32 Bioleaching gold recovery then the separation of the gold from the mercury by heating in Pressure It concentrates the heavy gold particles at the Process of Double Refractory Concentrates Pressure and Leaching of Gold from Refractory Sulfide Concentrates of Alkaline Glycine as an . إرسال رسالةWeb
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A review of gold extraction using noncyanide lixiviants: Fundamentals
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 …Web
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Comparative Study of Gold Extraction from Refractory Pyritic
Pressure oxidation is a hydrometallurgical oxidative pretreatment for refractory ores, such as sulfide ores. Here, simultaneous alkaline pressure oxidation and sodium cyanide leaching treatments were carried out on a pyritic ore from the Mulatos Mine located in Sahuaripa, Sonora, Mexico. Mineral characterization, agitation leaching, hot …Web
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Pretreatment of refractory gold minerals by ozonation before the
In a study by Xu et al. [24], the gold extraction from ore after the oxygen pressure alkaline leaching reached 78%. From the results by Fraser et al. [25], the number of necessary processing circuits for refractory gold pressure oxidation is dependent on the size of the selected autoclave. It can dramatically affect the pressure oxidation ...Web
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Gold Ore Processing, Volume 15
Purchase Gold Ore Processing, Volume 15 - 2nd Edition. Print Book & E-Book. ISBN 9780444636584, 9780444636706Web
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Alkaline Pressure Oxidation of a Gold-Bearing …
Alkaline pressure oxidation at 160°C, 2413 kPa O2, and 2 M NaOH resulted in about 98% sulfur oxidation and 86% arsenic dissolution. Cyanidation of the leach residue resulted in 82% Au...Web
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Gold Extraction from a Refractory Sulfide Concentrate …
Most gold deposits occur associated with sulphides like pyrite and arsenopyrite; thus, precious metal dissolution is possible by oxidizing auriferous sulfide concentrate using simultaneous pressure …Web
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Enhanced Gold Recovery from Alkaline Pressure Oxidized
Pressure oxidation is a widely accepted method to treat refractory gold ores. Gold recovery is generally lower from alkaline than acidic pressure oxidation discharge due to passivation and incomplete oxidation of mineral. Gold ore from Goldstrike, NV, is a typical refractory gold ore containing sulfide and carbonaceous matter. Alkaline …Web
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alkaline oand idation refractory gold-The Albion Process for …
Bacterial Oxidation of Refractory Sulfide Ores for Pressure Oxidation Overview Gold Ore Processing. ising for the biological leaching of refractory gold alkaline chlorination SO /air idation step is carried out using finely groundAn overview of the pressure oxidation of refractory gold ores is provided in this Oxidation Overview KG Recovery of Gold from …Web
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Refractory gold ores and concentrates part 1: mineralogical and …
ABSTRACT A comprehensive mineralogical and physico-chemical examination of two refractory gold ores and concentrates from the Ghanaian gold province was conducted to gain a better understanding of the differences in performance of gold cyanidation. Both ore were mainly silicates, carbonates, oxide, phosphate and sulphides. …Web
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Optimizing the alkaline oxidation pretreatment of a refractory gold …
Res. Express 10.1088/2053-1591/aae196. This study investigates the alkaline oxidation pretreatment process of Zarshuran refractory gold ore. Taguchi method-orthogonal array design (OAD) is applied to evaluate and optimize the influence of five main factors including solution pH, aeration rate, agitation speed, temperature, and oxidation …Web
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Pore Evolution in Refractory Gold Ore Formed by Oxidation …
Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold leaching efficiency. Roasting–leaching experiments, pore structure measurements, scanning electron microscopy (SEM), and X-ray diffraction …Web
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Alkaline Pressure Oxidation of a Gold-Bearing Arsenopyrite Concentrate
Gold extraction was found to be proportional to the degree of arsenopyrite oxidation. Alkaline pressure oxidation at 160°C, 2413 kPa O2, and 2 M NaOH resulted in about 98% sulfur oxidation and 86 ...Web
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Leaching of Gold and Silver from a Complex Sulfide Concentrate …
The leaching behaviors of gold and silver from a complex sulfide concentrate in copper-tartrate-thiosulfate solutions were investigated in this paper. Experimental parameters, including temperature, initial pulp pH, and concentration of copper, tartrate, and thiosulfate, were systematically studied. The copper-tartrate-thiosulfate leaching system …Web
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An Alkaline Glycine-Based Leach Process of Base and Precious …
It was found that alkaline glycine solutions selectively dissolve copper, zinc, and lead over precious metals. Gold and silver were then recovered in a subsequent leaching step using glycine and small amounts of cyanide (at starvation levels, implying no free cyanide is present). The leach system remains alkaline throughout both stages of ...Web
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Pressure Oxidation Overview
Acid and alkaline pressure oxidation of gold ores and concentrates are considered in terms of chemistry, process flowsheets, development history, materials of construction and other factors. ... Although pressure oxidation of gold ores and concentrates does not directly recover gold in a strict sense of the above definition, it is …Web
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(PDF) Metals Special Issue: A Review of the …
Oxidative chloride-, sulfide-, and ammonia-leaching processes are generally more applicable for the extraction of gold or platinum group metals as a byproduct from base metal sulfide concentrates.Web
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alkaline pressure oand idation of gold ncentrates
Alkaline Pressure Oand Idation Of Gold Concentrates Basic iron sulphate in pressure oxidation processing,pressure oxidation technology was developed more than years ago for the treatment of base metal concentrates and was adapted in the for the treatment of goldcontaining pyrite and arsenopyrite ores and concentrates the conditions that have ...Web
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Effect of sodium carbonate on alkaline self-leaching of gold from
The maximum gold extraction efficiency of gold-bearing flotation concentrate could achieve 91.56% under the following condition: a concentration of sodium …Web
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Environmentally friendly extraction of gold from refractory concentrate
Herein, we optimized the roasting of a gold flotation concentrate for a range of temperatures (400–800 °C) and times (60–300 min) using response surface methodology (RSM) and subjected the obtained residues to cyanidation, copper – ammonia – thiosulfate system, and copper – ethylenediamine – thiosulfate leaching, additionally ...Web
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Alkaline Pressure Oxidation of a Gold-Bearing Arsenopyrite …
The aqueous pressure oxidation of gold bearing arsenopyrite concentrates in alkaline solution was investigated as a function of O 2, pressure and NaOH concentration. …Web
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Gold concentrate marketing 101
Classification is critical for access to certain markets; however, classification of a gold-bearing concentrate as a 'gold concentrate' can be subjective. Generally, should the main revenue source of the concentrate be gold, then the miner and relevant authorities may classify the material as a 'gold concentrate'.Web
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Enhanced Gold Recovery from Alkaline Pressure Oxidized
Thiosulfate gold leaching of alkaline pressure oxidation slurry in the absence of mechanical activation yielded a gold recovery of 59.5% (Table 5 ). Gold …Web
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