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high pressure oxidation refractory

PRESSURE OXIDATION OF REFRACTORY GOLD ORES: THE

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 ...

The pressure oxidation approach that allows obtaining high gold recovery from double refractory materials was proposed. $/7$ : The chemical compositions of the concentrates

High Pressure Acid Leach & Pressure Oxidation

High Pressure Acid Leach (HPAL) and Pressure Oxidation (POX) testing services provide a unique opportunity to evaluate and optimise the most economically viable process routes for the recovery of most metals such as nickel from lateritic ores and gold from refractory ores. HPAL and POX are commercially proven and tested extraction

Pressure oxidation - Wikipedia

Pressure Oxidation is a process for extracting gold from refractory ore.. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them.Refractory ores require pre-treatment before the gold can be adequately extracted. The pressure oxidation process is used to prepare such ores for conventional gold extraction processes such as cyanidation.

PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE

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

Pressure Oxidation of a Refractory Sulfide Concentrate and ...

Aug 11, 2018 · Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. Normally, gold is extracted from neutralized autoclave leach residue by cyanidation.

Sun High Pressure Oxidation Of Refractory Gold Minerals

Sun High Pressure Oxidation Of Refractory Gold Minerals. Biooxidation Biooxidation uses sulfur consuming bacteria in a water solution to remove sulfur Pressure oxidation Utilizes oxygen and heat under pressure in a liquid medium to effect oxidation of sulfur by way of a controlled chemical reaction High pressure autoclaves.

MODELING OF HIGH PRESSURE PRETREATMENT PROCESS

Keywords: pretreatment process, pressure oxidation, refractory gold ore and concentrate, leaching, modeling Investigation of high pressure pretreatment process for gold leaching is the objective of

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 the aqueous ...

PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE

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

Pressure Oxidation of a Refractory Sulfide Concentrate and ...

Aug 11, 2018 · Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. Normally, gold is extracted from neutralized autoclave leach residue by cyanidation.

Moderate-Temperature, High-Pressure Oxidation ...

Moderate-Temperature, High-Pressure Oxidation In wet air oxidation, organic materials in a dilute aqueous mixture axe oxidized at elevated temperatures and pressures. Supercritical water oxidation operates at still higher temperatures and pressures (above the critical point of water at which hydrocarbons, for example, are highly soluble).

Pressure oxidation of pyrite-arsenopyrite refractory gold ...

The refractory ore must be destroyed or attacked by chemical means with the use of oxidative processes, such as oxidation by roasting [2], pressure oxidation [3], bio-oxidation [4], and ultrafine ...

MODELING OF HIGH PRESSURE PRETREATMENT PROCESS

Keywords: pretreatment process, pressure oxidation, refractory gold ore and concentrate, leaching, modeling Investigation of high pressure pretreatment process for gold leaching is the objective of

Basic Iron Sulphate in Pressure Oxidation Processing

ions. This results in very high cyanide consumption as well as other operating and environmental problems associated with high levels of thiocyanate. Typical autoclave operating conditions for a refractory gold process are a . temperature of 190 to 230OC, and an oxygen over-pressure of 350 to 700 kPa (50 to 100 psi). The oxidation of

Developments in the pretreatment of refractory gold ...

process is the same as in the high-pressure process and occurs as described by Equations [1–4]. The regeneration of NOx is finished under atmospheric pressure, or at high pressure in the two options, so, the rate of reuse of HNO 3 is different. The atmospheric

Amursk Pressure Oxidation (POX) Hub Expansion Project

Challenges. Polymetal International Inc. is undertaking the Amursk POX Hub Expansion to recover gold from double-refractory (high carbon) sulphide concentrate from five of their mines in Siberia, Eastern Russia, and East Kazakhstan. The project will double Polymetal’s concentrate treatment capacity to 250,000-300,000 t/a of refractory gold concentrate.

pressure oxidation process flow diagram of gold

Pressure oxidation (POX), high pressure oxidation (HiPOX) and ACTIVOX autoclave leaching are viable industry-standard technologies used to recover gold and other accessory metals. Read more The process is particularly well suited for treating refractory gold ores, which give low recovery when directly leached with cyanide.

Wet Oxidation of Municipal Sludge by the Vertical Tube ...

The need for high-pressure tanks, pumps, and compressors results in high capital cost and expensive, energy-consuming opera- tions. However, corrosion-resistant pres- sure vessel design, high-pressure liquid pump technology, and the state of devel- opment of heat exchangers are such that wet oxidation of municipal sludge in con- ventional ...

High temperature oxidation behavior of molybdenum borides ...

However, research related to high temperature oxidation and surface coating on molybdenum borides were hardly investigated. Voitovich et al. made a investigation about the oxidation behavior of borides of refractory metals including Mo 2 B 5 and introduced the weight change in the temperature range between 700 and 1200 °C .

(PDF) Phenol Oxidation Promoted by Chelated Iron ...

The oxidation process of phenol (150-1000 mg l-1) was carried out in a stirred tank reactor in batch conditions under extremely mild conditions, temperature (20-50ºC) and atmospheric pressure, in the presence of zero valent iron particles (10 g), ethylene diamine tetraacetic acid (EDTA, 0.30 mM) and air.

API RP 571 Damage Mechanisms Affecting Fixed Equipment in ...

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Application of eMAX analysis of pressure oxidation of ...

Feb 01, 1994 · High pressure oxidation of refractory ores and concentrates seems to be the preferred method of pretreatment today [6,7]. It effectively releases the locked gold by decomposing the host sulphide particles. In most cases gold recoveries in cyanidation have been 92% to 99% after pressure oxidation treatment [8].

Pressure Oxidation Overview - ScienceDirect

Jan 01, 2016 · An overview of the pressure oxidation of refractory gold ores is provided in this chapter. Often there are advantages to be gained by operating at temperatures above the normal boiling point of the solution and, therefore, at pressures above atmospheric. In such cases, the term pressure hydrometallurgy is used or applied.

High pressure oxidation of precursor alloys - American ...

"High-Pressure Oxidation of Refractory Metals--Experimental Methods and Interpretation" W. M. Fassel, Jr. et al., 2 Metalkde, 64(4) 286-295 (1973) no month. "The Internal Oxidation of Silver Alloys at High Pressures and in Atomic Oxygen" D. Stockel et al. AFSC Oxidation of Tungsten and other Refractory Metals, ML-TR-64-162 (Apr. 1965).

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 is a typical difficult-to-treat gold deposit, located in Guizhou province in western China. It was the first application of acid pressure oxidation in China.

The Leachox™ Refractory Gold Process – The Testing, Design ...

oxidation plant currently operating worldwide and represents a major breakthrough in the treatment of traditionally difficult to process refractory gold ores. he process offers a low T capital and operating cost route, but with similar high gold recoveries to bio -oxidation. INTRODUCTION . The Problem of Refractory Ores

Refractory Gold Ore Treatment Methods

Jul 14, 2016 · Pressure oxidation (POX) remains a further option for the oxidation of refractory sulfides. Several projects have been recently constructed: the Killita Project in Finland, the Amursk Project in Russia, the Pueblo Viejo Project in the Dominican Republic, and the MOPU expansion at Lihir.

Solutions for the treatment of wastewater with refractory ...

Other oxidation techniques are performed under conditions of high pressure and temperature that make the process more expensive and complicated. Despite not being a final solution (as it does not oxidize the COD), evaporation leaves an effluent with a very significant reduction in refractory COD content, and waste needing to be sent to an ...

REFRACTORY METALS - ASM International

(5070oF) in high vacuum or protective, reducing atmosphere. At these high temperatures, insulation of the hot zone is a problem and it is normal to use tungsten in high vacuum or a low partial pressure of hydrogen. • Heating elements. Hot zones usu-ally consist of a refractory metal ele-ment (single, two, or three phase) con-

pressure oxidation Archives - International Mining

“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 extraction - Wikipedia

Pressure oxidation; Albion process; The refractory ore treatment processes may be preceded by concentration (usually sulfide flotation). Roasting is used to oxidize both the sulfur and organic carbon at high temperatures using air and/or oxygen. Bio-oxidation involves the use of bacteria that promote oxidation reactions in an aqueous environment.

Autoclave Technology - Hatch

Some ores require a high-temperature, high-pressure pretreatment process before leaching in order to improve metal recovery from the complex ore. Autoclaves are a preferred component of the process for many large-scale sulfidic refractory bodies, including such processes as Au-Ag pressure oxidation; Cu-Ag-Au pressure oxidation; ...

Effect of Chloride Concentration on Gold Recovery in ...

Pressure Oxidation Process • Oxidation of sulfides, such as pyrite (FeS 2) and marcasite (FeS 2) at high T and P in autoclaves • Release of encapsulated gold grains Yes Pressure Oxidation Refractory? No Gold Ores Cyanidation Carbon Adsorption Reduction • Pre-treatment of “refractory” gold ores for cyanidation to be effective

Refractory gold reserves: Challenges and opportunities for ...

Mar 23, 2021 · 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. ... bio oxidation, roasting, or pressure oxidation (POX). This special treatment is required for two reasons: first, to liberate gold particles ...

Kevin S. Fraser, P.Eng., FCAE. - Principal Engineer - The ...

Kevin founded the High-Pressure Metallurgy Practice at Hatch in 1996; building the practice over more than 25 years into a world-class renowned engineering team that specializes in refractory gold pressure oxidation (POX), high pressure acid leaching (HPAL) and tube digestion.