High Pressure Oxidation Of Refractory Gold Minerals

Oxidation of a refractory gold concentrate using pressure

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 …

A clean and efficient innovative technology for refractory sulfide gold

This section first explored the generation of thiosulfate from sulfide gold ore by alkaline oxidation at atmospheric pressure. Notably, as a comparison experiment, the generation of thiosulfate from pyrite concentrate was also studied under the same oxidation conditions (40 and 80 °C) to scientifically identify the sulfur conversion capacity of this sulfide …

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 …

Study on high-efficiency sulfide removement using

The pyrite oxidation rate was calculated based on ICP analysis as follows: (4) R Fe = C Fe × V m × ω Fe × 100 % where C Fe is the concentration of iron in the filtrate, V is the volume of pretreatment solution, m is the mass of refractory gold ore before pretreatment, ω Fe is the mass concentration of iron in refractory gold ore, R Fe is ...

Gold recovery from refractory gold concentrates by …

Pressure oxidation technology for the treatment of refractory gold concentrates has been deployed in some countries. Shuiyindong gold deposit is one of the Carlin-type deposits which …

Treatment of carbonaceous refractory gold ores

Refractory ore treatment by this method normally gives gold extraction in excess of 95%. 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.

Gold Extraction from Refractory Minerals Using Acid …

Gold extraction was improved to 98% using pressure leaching, at 0.62 MPa, a temperature of 70 °C, a particle size of 26.5 μm, and a contact time of 120 min. Apparently, the oxidation in the acidic medium caused a greater porosity in the mineral, which provided a suitable environment that improved conditions in the cyanidation stage for gold ...

Optimizing the alkaline oxidation pretreatment of a refractory gold …

[7] Nanthakumar B, Pickles C A and Kelebek S 2007 Microwave pretreatment of a double refractory gold ore Miner. Eng. 20 1109–19. Go to reference in article; Crossref; Google Scholar [8] Li Q, Li D and Qian F 2009 Pre-oxidation of high-sulfur and high-arsenic refractory gold concentrate by ozone and ferric ions in acidic media Hydrometallurgy ...

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 are used to explore …

Pressure Oxidation Pretreatment of Refractory Gold

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 …

Study on Pre-oxidation of a High-Arsenic and High-Sulfur Refractory …

For arsenic-containing refractory gold concentrate, 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 investigated. The studied …

(PDF) Combined Bacterial and Pressure Oxidation for Processing High

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 ...

ACID PRESSURE OXIDATION OF REFRACTORY GOLD MINERAL …

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.

Basic iron sulphate

Arsenic is a common contaminant in refractory gold ores/concentrates and it's accepted that total pressure oxidation (POX) is the most appropriate technology to treat these due to their ...

Complete process and equipment solutions for refractory gold …

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-oxidative treatment option. ... The current high gold price is increasing the focus on the development of refractory gold ...

A FUNDAMENTAL INVESTIGATION OF THE HIGH …

pressure within a gold operation to reach the highest percent recovery, no matter what kind of ore is presented for treatment. For double refractory gold ores, the most crucial unit …

Basic iron sulfate — a potential killer in the processing of refractory

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 …

Minerals | Free Full-Text | Gold Extraction from a …

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 oxidation and cyanidation. …

Refractory Gold Ore Treatment Methods

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 mineral occurs'in ...

Basic Iron Sulphate in Pressure Oxidation Processing

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 …

Combined Bacterial and Pressure Oxidation for Processing High …

Microbially assisted bio-oxidation of sulfide concentrates in stirred-tank reactors (stirred-tank reactor bio-oxidation (STRB)) and acid pressure oxidation (POX) are widely used to pretreat refractory sulfide concentrates and increase gold extraction via cyanidation. Continuous STRB requires a comparatively long residence time; however, in some cases, it …

Enhanced Gold Recovery from Alkaline Pressure Oxidized Refractory Gold …

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 pressure oxidation …

Acid leaching decarbonization and following pressure oxidation …

Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions [J]. Minerals Engineering, 2009, 22: 111–115. Article Google Scholar LONG H, DIXON D G. Pressure oxidation of pyrite in sulfuric acid media: a kinetic study [J]. Hydrometallurgy, 2004, 73: 335–349.

Microwave Pyrolysis Pretreatment of High Arsenic Refractory Gold …

The process optimization and mechanism of microwave pyrolysis in a nitrogen atmosphere were studied to improve the gold leaching rate for high-arsenic-refractory gold sulfide resources, mainly containing minerals of elemental sulfur, dense pyrite, and arsenopyrite. The decomposability was evaluated using thermodynamic and thermogravimetric analyses. …

Flowsheet Development of A Refractory Gold Ore To …

The gold is particulate within arsenopyrite grains. The RGO ore is a complex refractory gold ore. Whilst flotation and concentrate roasting, pressure oxidation (POX), and bacterial leaching (BIOX) were all studied the environmental regulators would not agree to chemically changing the arsenopyrite containing the gold.

The Fate of the Arsenic Species in the Pressure Oxidation of Refractory

ABSTRACT 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 common approach is to immobilize arsenic as stable ferric arsenate phases during pressure oxidation, utilizing an existing process in the treatment of …

Processing of refractory gold ores

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. Therefore, it is a suitable substitution for conventional pretreatment techniques.

Enhanced Gold Recovery from Alkaline Pressure Oxidized …

Refractory gold ores contain preg-robbing matter, cyanide-/oxygen-consuming matter, and/or gold locked in sulfide or silicate minerals [1,2,3].To efficiently liberate and …

Exploring Non-ammoniacal Thiosulfate Gold Leaching and

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 behavior of …

Recovery of gold from sulfide refractory gold ore: Oxidation …

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 ...