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 …
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 …
The research on alternative oxidation roasting pretreatment of refractory gold ore has been ongoing for many years. However, it has yet to replace its role in industrial production of refractory gold ore. In this study, SR-AOPs …
Semantic Scholar extracted view of "Bio-oxidation of a high-sulfur refractory gold concentrate with a two-stage chemical-biological approach" by Guohua Wang et al.
Gold Metallurgy in South Africa, edited by R. J. Adamson and published by the Chamber of Mines of South Africa (1952), contains about six pages with meaningful contents on …
of refractory gold minerals and locking of submicroscopic gold in sulfide mineral structure etc. Gold process mineralogy helps address issues and problems related to gold ore processing. It provides useful information on process selection, flowsheet development, recovery improvement and reagent consumption optimization.
With the rising focus on the development of complex refractory ores, one of the major environmental challenges has been in the treatment and processing of arsenic-bearing minerals. An increasingly ...
The oxidation of refractory gold concentrates containing arsenopyrite and pyrite and the simultaneous dissolution of gold in aerated alkaline solutions at ambient temperatures and pressures without the addition of cyanide has been studied. It involves the following aspects: the chemistry of the oxidation of pure arsenopyrite and pyrite minerals in …
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 …
Acid pressure oxidation is currently strongly advocated as the most effective pretreatment method for refractory gold ores and concentrates. Arsenopyrite and pyrite are the most common mineral carriers of refractory gold.
In a certain region (Fig. 8), a high concentration of hydrochloric acid is a concern to a high oxidation leaching ratio of As-and Sb-bearing minerals of the refractory gold ore, as well as a high Au-extraction ratio of the oxidation residue. Coupled with the electrochemical analysis, high acidity is related to a better dissolution of As-Sb ...
Based on rapid chlorine oxidation, vanadium and carbon-rich refractory gold minerals react with chlorine gas at high temperatures to form compounds (AuCl 3) that are highly volatile, [24,25,26] enabling the extraction of gold. An effective cyanide-free extraction method realized to extract gold from vanadium and carbon-rich refractory …
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. To recover the gold, the host mineral must
Abstract For arsenic-containing refractory gold concen-trate, gold recovery by leaching is extremely difficult due to the encapsulation of gold in arsenopyrite and pyrite. In this work, the pre-oxidation of a high-arsenic and high-sulfur refractory gold concentrate in the acidic potassium permanganate or hydrogen peroxide solutions has been
This insoluble layer restricts the access of the thiourea used to extract the gold from the mineral, causing low metal recuperation and/or high operational costs. The oxidation process enables the liberation of gold encapsulated in sulfide minerals, making the gold available for processing via traditional routes.
The eect 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.
2.1 Microwave pre- treatment of refractory gold ores . Most of refractory gold occurs within sulphide minerals such as FeS 2 and FeAsS and are treated by roasting, pressure leaching or bacterial leaching to render the gold amenable to recovery by subsequent treatment techniques (Haque, 1987).
Autoclave leaching of refractory gold ores on an industrial scale started in the 1980's because of the high gold price and because pressure oxidation is an environmentally accepted alternative to roasting. Since 1985 about five autoclave leaching plants have been commissioned for treating refractory gold ores.
For the high sulfur refractory gold concentrate with 41.82% sulfur and 15.12 g/t gold, of which 82.11% was wrapped in sulfide, a well-controlled stirring tank leaching was carried out to improve the bio-oxidation efficiency. Results show that bio-oxidation pretreatment can greatly improve the gold recovery rate of high-sulfur refractory gold …
The free radicals generated by ultrasound-activated persulfate effectively promoted the oxidation of sulfide in the gold ore. The pretreatment efficiency of this …
The presence of gold telluride minerals may render an ore refractory, the extent of this depends on the telluride mineral present and the mineralogical association [3]. Gold, silver, and gold/silver-telluride minerals in ores dissolve more slowly than native gold in cyanide solutions, which results in less efficient gold extraction [4].
Semantic Scholar extracted view of "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" by Shiqi Zhang et al.
Gold ore from Goldstrike, NV, is a typical refractory gold ore containing sulfide and carbonaceous matter. Alkaline pressure oxidation followed by thiosulfate …
Although there is a wide range of procedures for the recovery of gold from refractory gold ore, there are challenges that need to be addressed during the extraction. Refractory gold mining often involves complex extraction processes, such as pressure oxidation or bioleaching, which can release harmful chemicals and pollutants into the …
In this study, A novel method for gold recovery from refractory gold ore was proposed with the purpose of improving recovery efficiency of gold and reducing environmental pollution.
This paper describes the oxidative dissolution kinetics of sulfides with gold occlusion within pyrite and arsenopyrite. Shake flasks tests and column leaching of a low grade gold ore from China were carried out with domesticated mixed acidophiles isolated from acid mine drainage. Both test show that the main factors accelerating sulfide oxidation was mainly …
High-grade refractory gold reserves offer the potential for lower costs per ounce despite higher capital and operational costs. A focus on three action areas can help maximize the opportunity.
The application of pressure oxidation (POX) followed by thiosulfate gold leaching is an efficient method used to extract gold from double refractory gold ores containing both sulfide and carbonaceous matter. This process is expected to result in high gold recovery rates, as it liberates gold from sulfides and eliminates the preg-robbing …
Compared to the untreated refractory gold concentrate, the higher gold recovery confirms that a large portion of the gold was refractory in nature, with the gold occurring as either solid solution …
The best type of oxidation for double refractory ore, especially due to dealing with the carbon component, is high temperature oxidation, or roasting. Figure 1.1 shows where …
The complex mineralogy of the Porgera resource has a pronounced effect on process selection for the recovery of refractory gold and silver. Intimate association of gold with pyrite necessitates a high degree of sulphur preoxidation to achieve acceptable levels of gold recovery. Acid pressure oxidation has been demonstrated to be the only …
In this study, a two-stage chemical-biological oxidation approach was utilized to intensify the oxidation process of a high sulfur refractory gold concentrate. It was found that the oxidation efficiency and recovery rate of gold were elevated significantly with a two-stage approach.
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