However, most of the sulfide minerals in a refractory gold concentrate react to form a harmful gas during roasting and the iron oxide produced during roasting encapsulates invisible or fine gold . Pyrite is the most abundant sulfide mineral in refractory gold ore and its oxidation is thermodynamically favorable in the environment .
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@article{Zhang2022ColumnBO, title={Column bio-oxidation of low-grade refractory gold ore containing high-arsenic and high-sulfur: Insight on change in microbial community structure and sulfide surface corrosion}, author={Shiqi Zhang and Hong-ying Yang and Pengcheng Ma and Zuochun Luan and Lin-lin Tong and Zhe-nan Jin and Wolfgang …
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The refractory minerals with a high sulfide content require an oxidative pretreatment to increase the extraction of gold and silver in the cyanidation process [2, 5, 10]. The most common pretreatments at present are roasting [11,12,13], chemical oxidation [1, 2, 4, 5, 14], and biooxidation [15,16,17].
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1. Introduction. The irregular discharge of wastewater has caused serious hazards to human production and life, such as the deterioration of water quality and the shortage of drinking water [1].Refractory organic contaminants in wastewater have the characteristics of strong obstinacy and high toxicity, which has become one of the most …
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Bio-oxidation of refractory sulfidic gold minerals has been applied at the commercial scale as a pre-treatment to improve gold yields and reduce chemical consumption during gold cyanidation.
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The mineral composition analysis of the pyrite concentrate (Fig. 1 (a)) shows that it has the lowest content of gangue minerals and only the pyrite was (FeS 2) measured. ... Enhanced oxidation capacity of refractory sulfide gold ore3.2.1. Thermal activation pretreatment.
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The refractory gold ore with high arsenic and sulfur used in this study was obtained from Yuantong Mining Company, Inner Mongolia, China. The chemical composition of the raw gold ore is presented in Table 1. Fig. 1 (a) gives the X-ray diffraction diagram of the raw gold ore. The data showed that pyrite and arsenopyrite are the main …
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Gold Extraction from a Refractory Sulfide Concentrate by Simultaneous Pressure Leaching/Oxidation ... Characterization of the ores showed that pyrite and quartz were the main minerals present in ...
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Carbonaceous sulfidic gold ores are commonly double refractory and thus require pretreatment before gold extraction. In this paper, the capacity of pre-bio-oxidation can simultaneously decompose sulfides or deactivate carbonaceous matters (CM) from a double refractory gold ore (DRGO) using pure cultures of A. ferrooxidans or L. …
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Acid pressure oxidation is currently strongly advocated as the most effective pretreatment method for refractory gold ores and concentrates. Arsenopyrite and pyrite …
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continuously decreasing, while refractory gold minerals are becoming the most important resources in the eld of gold extraction. In these original ores, most of the gold is encapsulated in the lattice of pyrite and arsenopyrite, resulting in dif- ... at pH 10.5–11.5 after acid pressure oxidation pretreatment of refractory gold ores. However ...
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Cyanide-refractory ores constitute 30 % of the world's gold mineral resource base. With the global decrease in the availability of high-grade and free-milling ores, low-quality ores, including ...
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The most effective method to solve the problem of insufficient contact between gold particles and leaching reagent is oxidation pretreatment before leaching.
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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 …
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In this paper, we describe the ther-modynamic considerations of preoxidation of pyrite and arsenopyrite, the main minerals of the refractory gold ore, and the efect of the pressure oxidation, one ...
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This paper presents the results obtained by processing a gold and silver telluride mineral concentrate from a mine in Colombia. An acid wash, also known as acidification, was carried out, followed by oxidation with nitric acid as a pretreatment. Cyanidations of the pretreatment residues were carried out and the results were …
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The Sand Farming is one of novel biooxidation processes suitable for sulphide oxidation of low-grade refractory gold ores. It has been previously proven to be feasible and more efficient compared ...
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Strain selection for high temperature oxidation of mineral sulfides in reactors. In . Harnessing Biotechnology for the 21st Century: Proceedings of the Ninth International Biotechnology Symposium and Exposition. ... Bio-oxidation of a refractory gold bearing high arsenic sulphide concentrate: a pilot study.
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The pretreatment of gold ores before cyanidation is a challenging problem due to the world's annual huge waste of refractory gold minerals. Generally, the leaching of gold by cyanidation without any pre-oxidation causes an extraction lower than 90%. In recent decades, a variety of treatment and pretreatment methods have been used to …
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To increase the efficiency of gold extraction, oxidation pretreatment before gold leaching decomposes the sulfide matrix in refractory ores and liberates gold particles. Pressure oxidation and biological oxidation are common hydrometallurgical methods for sulfide mineral degradation [1].
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The paper presents an overview of bio-oxidation of sulphidic refractory gold ores prior to gold cyanidation. This review discusses several factors, more importantly, oxygen requirements and oxygen ...
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Abstract Biomining through bioleaching and bio-oxidation aims at recovering desired metals at the required specifications with lower environmental impact and costs from ores and waste streams. Research and developments related to the process technology and efficient implementation of this approach are advanced worldwide. Small …
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Arsenopyrite, which is a typical gold-bearing mineral, is widely distributed in gold tailings. In this study, we have examined the surface morphology of arsenopyrite before and after oxidation, the types of oxidation products, and the oxidation mechanism. ... Effect of grain size on the bacterial oxidation of a refractory gold sulfide ...
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Owing to the decomposition of carbon-bearing minerals, such as dolomite and calcite, and the oxidation of pyrite at 650 °C, a large amount of gas was released to form more mesopores. This facilitated …
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Where gold is associated with arsenic, antimony, tellurium, and certain other minerals, it is often only partly soluble in cyanide solution. The difficulty is usually more of a physical than a chemical one but special methods of treatment may be required. Gold Leaching & Processing of Arsenic Ore Mispickel (Arsenopyrite: FeAsS).6 When this …
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The bacterial oxidation (BIOX) process for the pre-treatment of refractory ores for gold recovery was developed by the Genmin Process Research laboratory. Early work started in the late 1950's when the bacteria strain, "Thiobacillus ferrooxidans" was isolated from effluents pumped from the West Rand Consolidated underground mine but …
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Refractory gold concentrates often contain sub-microscopic gold that is encapsulated within the crystal matrix of iron sulphide minerals such as pyrite, pyrrhotite and arsenopyrite.
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The ozonation of refractory minerals can improve gold extraction through direct treatment or indirect oxidation. It minimizes gold entrapping with refractory minerals by creating desired oxidizing conditions for sulphides destruction.
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Refractory gold ores have poor gold recoveries with direct cyanide leaching. Typically the refractoriness is due to encapsulation of the gold particles inside the host mineral. To liberate gold for leaching the host mineral must be broken by mechanical or chemical means. The aim of this study was to study the effect of temperature, oxygen partial …
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In order to render gold amenable to the subsequent cyanide leaching, oxidation pretreatment is considered to be an effective method for treatment of …
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