(PDF) Alkaline Pressure Oxidation of a Gold-Bearing ...

Pilot plant pressure oxidation of refractory gold-silver concentrate from Eldorado Gold Corporation's Certej Project in Romania T. Chan Sherritt Technologies, Sherritt International Corporation, Street, Fort Saskatchewan, AB, T8L 4K7, Canada, M. Collins Sherritt Technologies, Sherritt International Corporation, Street, Fort ...

USA - Gold recovery using controlled oxygen ...

May 11, 2014· The etching of gold is a key enabling technology in the fabrication of many microdevices and is widely used in the electronic, optoelectronic and microelectromechanical systems (MEMS) industries. In this review, we examine some of the available methods for patterning gold thin films using dry and wet etching techniques. Dry methods which utilise reactive ion etching (RIE) have a number of ...

Pressure Oxidation Leaching Process

pressure oxidation refractory gold. 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

(PDF) Pressure oxidation of double refractory gold ...

A process for the pressure oxidation leaching of non-ferrous metal sulphidic material which comprises providing an autoclave assembly which has a series of successive compartments, the first compartment of which being substantially larger in size than each of the remaining compartments. An oxygen partial pressure is provided in the autoclave assembly in the range of from about 50 to about 2000 ...

Pretreatment Process on Refractory Gold Ores with As

Sep 01, 2003· Catalytic wet air oxidation of a representative organic compound (aqueous solution of 5 g l −1 succinic acid at 190 °C and 50 bar total air pressure) was investigated over gold on titania prepared from the deposition–precipitation method (with urea or NaOH) and compared to experiments performed over a Ru/TiO 2 catalyst. These preliminary results demonstrate that gold catalysts are ...

Wet Oxidation - an overview | ScienceDirect Topics

"Pressure oxidation was selected as the most feasible processing technology for double refractory ores. It is able to achieve gold recoveries of 96% by utilising high temperatures, elevated pressure and oxygen to recover encapsulated gold, while conventional cyanidation methods would result in sub-optimal recovery rates of 20-40%.

Gold etching for microfabrication | SpringerLink

What is PRESSURE OXIDATION? What does PRESSURE OXIDATION mean? PRESSURE OXIDATION meaning - PRESSURE OXIDATION defini...

ALTA MetBytes - What's Happening in Gold Ore Processing

CSIRO, Australia, has developed a thiosulfate-based reagent system for gold leaching that has excellent stability and shown broad applicability in the laboratory compared to the thiosulfate system commercially implemented by Barrick to treat double refractory gold ore following pressure oxidation at its Goldstrike Mine in Nevada, USA.

Pressure Oxidation of a Refractory Sulfide Concentrate and ...

Mar 22, 2016Patents Assigned to Barrick Gold Corporation acid pressure oxidation of the pressure oxidation feed, and recovery of gold. The present invention is directed to flotation of refractory gold sulfide ores and to pressure oxidized residue neutralization using flotation tailings that have been contacted with an off gas of pressure oxidation.

Pressure Oxidation | Mining | SGS

The major difference in the growth of wet and dry oxide is the growth rate; dry oxide grows much slower than wet oxide. In views of quality, a dry oxidation produces a more uniform and denser thermal oxide with even higher dielectric strength than wet oxide. Equipment Description The oxidation system is a three-zone atmosphere pressure furnace ...

Pumps for Wet Oxidation of Waste Water | LEWA

The heterogeneously catalyzed oxidation of bioethanol offers a promising route to bio-based acetic acid. Here, we assess an alternative method to support gold nanoparticles, which aims to improve selectivity to acetic acid through minimizing over-oxidation to carbon dioxide. The most promising support system is 5 wt % titanium on silica, which combines the high surface area of silica with the ...

Furnace – Oxidation (Wet / Dry)

Gold extraction was found to be proportional to the degree of arsenopyrite oxidation. Alkaline pressure oxidation at 160°C, 2413 kPa O2, and 2 M NaOH resulted in about 98% sulfur oxidation and 86 ...

Gold catalysts supported on titanium oxide for catalytic ...

Batch Autoclave Laboratory Procedures: The vessel used for the laboratory pressure oxidation process was a two-liter Parr titanium autoclave with dual impellers. It was heated and cooled externally and was pressurized with commercial-grade oxygen. A positive bleed of offgas was maintained in each test; the rate was measured in the offgas after the steam was removed with a condenser and ...

pressure oxidation Archives - International Mining

Sep 01, 2003· Catalytic wet air oxidation of a representative organic compound (aqueous solution of 5 g l −1 succinic acid at 190 °C and 50 bar total air pressure) was investigated over gold on titania prepared from the deposition–precipitation method (with urea or NaOH) and compared to experiments performed over a Ru/TiO 2 catalyst. These preliminary results demonstrate that gold catalysts are ...

Pressure oxidation - Wikipedia

Wet oxidation is the destruction of organic compounds by the introduction of a suitable oxidation agent. The reaction takes place in the liquid phase under high pressure and high temperature. The goal is the destruction of critical compounds in decomposable materials.

high pressure oxidation of refractory gold minerals in japan

A process for recovering gold from a refractory auriferous ore containing sulfide sulfur. An aqueous slurry of refractory auriferous ore is subjected to pressure oxidation in an autoclave while the distribution of oxygen to the various compartments of the autoclave is controlled in order to …

USA - Process for the pressure oxidation acid ...

arsenopyrite gold concentrate. Batch oxidation tests in an autoclave were done using a factorial design. Different responses were measured and analysed to study effect of the three factors and oxidation kinet-ics. Generally, high slurry density required high temperature and oxygen partial pressure to reach com-plete oxidation. Oxidation ...

Pilot plant pressure oxidation of refractory gold-silver ...

Mar 22, 2016Patents Assigned to Barrick Gold Corporation acid pressure oxidation of the pressure oxidation feed, and recovery of gold. The present invention is directed to flotation of refractory gold sulfide ores and to pressure oxidized residue neutralization using flotation tailings that have been contacted with an off gas of pressure oxidation.

PRESSURE OXIDATION OF REFRACTORY GOLD ORES: THE …

upgrading and a model for selective polyol oxidation (Scheme 1a).1,2 Supported gold nanoparticles prepared by wet chemical methods, such as incipient-wetness impregnation and deposi-tion precipitation, can be effective catalysts for glycerol oxidation.3 Gold catalysts can achieve high selectivity to C 3

Pueblo Viejo – Pressure Oxidation and Air Separation Project

A process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. The oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between 7 and 8.7 while the slurry is agitated in a ...

Redox potential measurement during pressure oxidation (POX ...

Wet oxidation is a form of hydrothermal treatment. It is the oxidation of dissolved or suspended components in water using oxygen as the oxidizer.It is referred to as "Wet Air Oxidation" (WAO) when air is used. The oxidation reactions occur in superheated water at a temperature above the normal boiling point of water (100 °C), but below the critical point (374 °C).

pressure oxidation refractory gold - lafermeduvar

Pressure oxidation (POX) leaching has been commercially applied to refractory gold ores since the 1980s. In the process, sulphide material is oxidised and dissolved in order to release the gold encapsulated in the sulphide matrix, making the gold available for further recovery.