Outotec can deliver the 3 main oxidative processes for the treatment of refractory gold concentrates – BIOX, pressure oxidation, and roasting – and also supply equipment for ultra-fine grinding as a fourth, non …
A typical pressure oxidization (POX) circuit for refractory ores consists of the following main process steps: comminution and flotation followed by carbonate removal, chloride removal, pressure oxidation, vent-gas …
High-pressure oxidation processes are difficult to carry out, because they require high-capital cost autoclaves. Atmospheric-pressure oxidation processes are easier to manipulate, but …
It has been suggested that refractory gold reserves, which require more sophisticated treatment methods in order to achieve oxide-ore recovery rates, correspond to 24% of current gold reserves and 22% of gold …
The pressure oxidation of both the concentrate and STRB residues increased Ss oxidation by 97–99% and gold recovery by 96–97%. For 2 days, STRB decreased the Ss content and increased the ...
Double refractory gold ores are known as ores from which gold extraction is poor due to the presence of sulphide minerals and carbonaceous matter (CM) in the ore which preg-rob dissolved gold. In this study, a double refractory flotation concentrate from a mine in Barberton was used to evaluate the effectiveness of pressure oxidation (POX) pre ...
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 …
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 …
High temperature pressure oxidation (>190°C) is a wellrecognized and versatile metallurgical oxidative pre-treatment process commonly used to liberate gold from refractory sulfide ores and concentrates. The pressure oxidation of refractory gold ores was first commercially applied in 1985, at Homestake Mining Company's McLaughlin mine in the United …
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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 …
High temperature pressure oxidation (>190°C) is a wellrecognized and versatile metallurgical oxidative pre-treatment process commonly used to liberate gold from refractory …
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 ...
PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE REFRACTORY GOLD CONCENTRATE Lauri RUSANEN, Jari AROMAA, Olof FORSEN Aalto University, Department of Materials Science. P.O. Box 16200, Aalto, Espoo, Finland, [email protected] Abstract: Refractory gold ores have poor gold recoveries with direct cyanide leaching. Typically the
Arsenolite is the most soluble and potentially toxic mineral on the site, and some high levels of total As (>70 wt%) principally reflect local accumulations of arsenolite. ... The Fate of the Arsenic Species in the Pressure Oxidation of Refractory Gold Ores: Practical and Modelling Aspects View Article. Journal Information.
Typically, gold is encapsulated or finely disseminated in refractory gold ores and the direct cyanidation is not effective for gold extraction from these ores, even after the ore is ground to exceeding small particles (Nazari, 2017, Corrans and Angove, 1991).Especially for sulfide refractory gold ores, in order to recover gold, many oxidation pretreatment …
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 pressure and slurry density on pressure oxidation of pyrite-arsenopyrite gold concentrate.
Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold carriers in refractory gold ores, however, hinder gold extraction due to the high consumption of a lixiviant. In this study, a new method to improve gold extraction from sulfide bearing gold ores is proposed based on the model experiments using a mixture of gold powder and ...
Pressure Oxidation Pressure oxidation is employed to liberate gold and silver in refractory sulfide concentrates often and ores. The main pressure oxidation products from iron sulfide minerals are sulfuric acid (and metal sulfates) and hematite. Depending on the conditions within the autoclave, acid containing iron compounds can be formed.
Chemical oxidation is a promising pretreatment method for refractory pyrite enclosure to enhance Au/Ag extraction. Here, persulfate was employed for stepwise oxidation of a refractory pyrite concentrate with encapsulated Au/Ag: (i) pyrite oxidation began with heating-activation persulfate, where hydroxyl radical (•OH) acted as the primary oxidative species for fast …
Refractory gold concentrates often contain submicroscopic gold that is encapsulated within the crystal matrix of iron sulfide minerals, such as pyrite, pyrrhotite and arsenopyrite. To recover the gold, the host mineral must generally be broken down chemically by oxidative processes, such as roasting, pressure oxidation or bacterial leaching, which …
High Pressure Oxidation (HPOx): Refractory ores where gold is contained within sulphides, such as pyrite or arsenopyrite, can be chemically oxidised to enhance gold recovery. …
Within the deposit three main zones of mineralisation have been identified. Gold occurs as both free gold and as refractory gold in pyrite and arsenopyrite. As the gold occurs with both arsenopyrite and pyrite, conventional smelting of the ore is undesirable as this attracts heavy penalties due to the presence of arsenic.
disseminated gold from the flotation concentrate resulted from processing of a refractory ore of one of Russian gold deposits. Concentrate description Gold grade of the head flotation concentrate was 29.6 g/t. The concentrate size was 80% -80 um. Mineral composition of the concentrate comprises 17% of rock-forming minerals, 59% of pyrite and 24%
Pressure Oxidation (POX) is a process used to extract gold, copper, zinc, molybdenum, and uranium from refractory ore bodies. The POX process utilizes elevated temperatures (roughly …
concentrate was treated by pressure oxidation in acid (Dong et al., 2015; Luo et al., 2015). Now, the flotation-pressure oxidation-cyaniding technology was taken to deal with the refractory gold ore in shuiyindong despite, the recovery of gold was …
Biooxidation is simpler, safer and less expensive than roasting or pressure oxidation. For each gram of ore, literally trillions of microorganisms, each smaller than 10 microns, attack the …
LI, D.-X. Developments on the pretreatment of refractory gold minerals by nitric acid. World Gold Conference 2009,The Southern African Institute of Mining and Metallurgy, 2009. ... High-pressure oxidation processes are difficult to carry out, because they require high-capital cost autoclaves. Atmospheric-pressure oxidation processes are easier to
Arsenopyrite and pyrite are the most common mineral carriers of refractory gold. Pressure oxidation of these refractory gold mineral carriers is a very complex reaction system involving several oxidation and hydrolytic reactions which occur in series and/or parallel. Moreover these oxidation reactions are highly exothermic.
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 …
Gold miners are facing a reserves crisis, and what is left in the ground is becoming more and more challenging to process.Refractory gold reserves, which require more sophisticated treatment methods in order to achieve oxide-ore recovery rates, correspond to 24 percent of current gold reserves and 22 percent of gold resources worldwide (Exhibit 1).
