Gold, a signicant precious metal, has high corrosion resist-ance, excellent electrical and thermal conductivity []. In 1 the eld of gold extraction and smelting, refractory gold ore is one of the most important gold resources at present [2]. Approximately 30% of the world's gold production is derived from refractory gold ore, and this proportion
Gold, a significant precious metal, has high corrosion resistance, excellent electrical and thermal conductivity [].In the field of gold extraction and smelting, refractory gold ore is one of the most important gold resources at present [].Approximately 30% of the world's gold production is derived from refractory gold ore, and this proportion is expected to increase even …
SGS MINERALS SERVICES. TECHNICAL PAPER 2009-06 2009. BASIC IRON SULPHATE – A POTENTIAL KILLER FOR PRESSURE OXIDATION PROCESSING . OF REFRACTORY GOLD CONCENTRATES IF NOT HANDLED APPROPRIATELY. C.A. FLEMING –– SGS MINERALS. ABSTRACT. Refractory gold concentrates often contain sub-microscopic gold that is …
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.
from refractory gold mines, and this proportion will definitely increase in the future [7, 8]. Generally, the formation of refractory sulfide gold deposits is closely related to sulfide minerals, such as pyrite, arsenopyrite, pyrrhotite and chalcopyrite, among which pyrite is the most important gold-bearing mineral [9].
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 commercially proven process capable of …
A two-stage chemical-biological oxidation approach, which applied a high temperature chemical oxidation stage prior to the bio-oxidation stage, was employed to accelerate the bio-oxidation rate of Axi gold concentrate with pyrite as the main sulfide phase. The extraction levels of Fe and S were 67.0% and 72.9% in the traditional one-stage bio-oxidation approach, …
Gold resources are explored and mined widely in the world. But with the increasing depletion of free-milling gold ores, the mining and utilization of refractory gold ores have become a huge challenge for metallurgy and mineral processing (Konadu et al., 2019).At present, gold acquired from refractory gold ores has been accounted for one-third of the total gold production …
In mining industries, biomining (comprising biooxidation and bioleaching) is implemented to extract metals from specific ores and waste streams with less environmental effect and expense. Usually, micron-sized gold particles are held in a crystal lattice of iron sulfide minerals and expensively extracted using common approaches. Researchers and industries …
The feature of refractory gold ore is that the gold grain size is extremely fine, and exists in invisible or submicroscopic gold, which is encapsulated in arsenopyrite, sulfide, carbonate or ...
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 experimental results revealed that …
refractory gold. This is particularly true when an appre ciable portion ofthe gold is associated with sulfides and is not amenable to conventional cyanidation. A briefreview of the literature on pressure oxidation of refractory gold matenals is presented. The chemistry of the aqueous oxidation of arsenopyrite and pyrite is discussed. Data
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 ...
A "refractory" gold ore is an ore that has ultra-fine gold particles disseminated throughout its gold occluded minerals. These ores are naturally resistant to recovery by standard cyanidation and carbon adsorption processes. ... Miners could ship high-grade refractory ore or concentrate from several mines to centralized processing ...
Gold ores containing pyrite and arsenopyrite are commonly recognized as refractory ores, and especially, the gold leaching rate is very low, when these minerals exist together, because ultrafine gold particles are locked up in sulphur and arsenic mineral matrix [24, 25]. Although the thermodynamic study on the oxidation of pyrite and ...
Autoclave oxidation, bacterial and chemical liberation, roasting, acid oxygen processes, atmospheric oxidation prior to cyanidation are applied to process refractory sulphide …
The oxidation of sulfide minerals is of central importance due to the acid mine drainage (AMD) production. ... For the high sulfur refractory gold concentrate with 41.82% sulfur and 15.12 g/t gold ...
options for refractory gold ores: roasting; pressure oxidation; bio-oxidation; and ultra-fine grinding. In roasting, pressure oxidation and bio-oxidation, the iron sulphide minerals are oxidised to …
During bio-oxidation refractory gold ores processes, mineral decomposition is believed to be mostly due to chemical attack by ferric iron, with the main role of the microorganisms being to reoxidize the resultant ferrous iron back to ferric iron (Rawlings, 2002). As a reference point, in this study experiments were generally conducted with ...
The reasons for gold-bearing materials refractory nature and behaviour features of carbonaceous matter during pressure oxidation of concentrates were discussed.
Hydrometallurgical processing of refactory gold ores as a rule generally entails production of a gold-rich bulk sulphide concentrate which then requires oxidation to enable recovery of the …
The depletion of large oxidized‑gold deposits triggered the processing of refractory ores, where the precious metals are associated with sulfides and other compounds of base metals, antimony or arsenic (Jha and Kramer, 1984).There are several alternatives for the treatment of refractory minerals, which have been studied for several decades (Chilton, 1958; …
The use of thiosulfate to extract gold from refractory ores is promising because of its non-toxicity and high selectivity. Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold ...
The gold group at SGS Minerals Metallurgy (Malaga, Western Australia) has conducted a test programme in which a refractory gold ore sample was beneficiated by bench-scale floatation to generate a bulk sulphide concentrate grading 10.6 g/t Au, 13.1% S, 11.4% Fe, 0.18% C and 2.36% As. Mineralogical analyses determined that gold in the ore was ...
Currently, a greater percentage of gold is extracted from low grade, refractory gold ores, following depletion of most high grade deposits [8]. Increasing complexity of these refractory ores warrants improvement in our fundamental and applied knowledge un-derpinning sustainable, cost-effective, commercial gold extraction process and commod-
In most refractory raw gold minerals, more than 90% of gold is distributed in sulfide, encapsulated or embedded in the crystal lattice of pyrite and/or arsenopyrite in the form of fine or sub-fine particles. ... High redox potential promotes oxidation of pyrite under neutral conditions: Implications for optimizing pyrite autotrophic ...
In order to improve the thiourea gold leaching rate of a low-grade arsenic–sulfur-containing refractory gold ore in Xinjiang, a microbial pretreatment was used to oxidize pyrite and arsenopyrite ...
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.
Gold is a precious strategic metal that is driving everyday life, the electronics industry, and the global economy (Zhan et al., 2021; Zhang et al., 2022a, Zhang et al., 2022b, Zhang et al., 2022c, Zhang et al., 2022).However, with the depletion of high-quality gold ore, refractory gold resources (gold recovery efficiency rate of <50% after direct cyanide leaching …
To avoid toxic arsenic containing gas formation, arsenic-bearing sulfide minerals in refractory gold ores can be pre-oxidized in low-temperature processes to minimize thiosulfate decomposition in the same manner as high …
Pressure oxidation of gold containing concentrates and ores is an effective pretreatment for liberating refractory gold. This is particularly true when an appreciable portion of the gold is associated with sulfides and is not amenable to conventional cyanidation. A brief review of the literature on pressure oxidation of refractory gold materials is presented. The chemistry of the …
High acidity promotes sulphide oxidation, whereas high temperature can lead to the formation of elemental sulphur, which may adversely affect gold recovery and the formation of …
Refractory gold ores and concentrates are characterised by low gold recoveries and high cyanide consumptions when subjected to direct cyanide leaching. Therefore an oxidation pretreatment step is required before cyanidation that will break up the sulphide lattice and render gold particles accessible to cyanide ions.
Measured electrode potential and O2 consumption during POX of the refractory gold ore at 20 %wt. solids. a) 200 °C and 50 psi, b) 200 °C and 110 psi, c) 220 °C and 50 psi, and d) 220 °C and ...
Currently, there is a lack of research on column bio-oxidation for low-grade refractory gold ore with high arsenic and sulfur content. Therefore, it is essential and significative to investigate ...
For double refractory gold ores, the most crucial unit operation is performed by the roaster by creating a high temperature oxidation of the ore. An efficient roasting operation creates a …
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 ... various pyrometallurgical and hydrometallurgical pretreatments have been applied to reduce the influence of the sulfide minerals in the process of leaching gold (Li ...
Pyrite and arsenopyrite were both common gold-bearing sulfide minerals and often intergrown with each other ... Novel two-step process to improve efficiency of bio-oxidation of Axi high-sulfur refractory gold concentrates. Trans. Nonferrous Metals …