Pressure Oxidation Pretreatment of Refractory Gold ...

1984-2-1  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.

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

The reasons for gold-bearing materials refractory nature and behaviour features of carbonaceous matter during pressure oxidation of concentrates were discussed. The

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Pressure Oxidation of a Refractory Sulfide Concentrate and ...

2018-8-11  Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores

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pressure oxidation refractory gold - Hitlers Hollywood

2021-8-31  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 pretreatment before the gold can be adequately extracted

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ACID PRESSURE OXIDATION OF REFRACTORY GOLD

1987-1-1  ACID PRESSURE OXIDATION OF REFRACTORY GOLD MINERAL CARRIERS G.P. Demopoulos and V . G . Papangelakis Department of Mining and Metallurgical Engineering McGill U n i v e r s i t y , Montreal, Quebec, Canada H3A 2A7 ABSTRACT Acid pressure oxidation is c u r r e n t l y strongly advocated as the most e f f e c t i v e pre treatment method f o r r e f r a c t o r y gold ores

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Pressure oxidation overview - ScienceDirect

2005-1-1  The utilization of a pressure-oxidation circuit to treat refractory gold ores or concentrates is a complex decision, taking into consideration capital costs, operating costs, gold recovery, and environmental impacts. The payback and internal rate of return (IRR) has to be evaluated in the decision for selecting the process.

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Titanium Internals in Refractory Lined Pressure Oxidation ...

2018-4-14  Titanium Internals in Refractory Lined Pressure Oxidation Autoclaves Author: Franceschini, M Author: Ugarenko, C Hatch Ltd. - Autoclave Technology, Sr. Piping Engineer Hatch Ltd. - Autoclave Technology, Welding Technologist Co-Author: Gothard, S W.E. Smith Engineering Pry. Ltd., General Manager 4 Bending the 10 mm Titanium Gr. 2 to a 50 mm

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PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE

2012-10-4  Pressure oxidation is typically operated in temperatures of 190 to 230°C and oxy-gen overpressure of 350 to 700 kPa (Fleming 2010). Under these conditions sulfide sulfur is oxidized into sulfates and bisulfates and iron dissolves as ferrous iron or fer-ric iron. Ferric iron can hydrolyse and precipitate as hematite, basic iron sulfate or jarosite, and also formation of elemental sulfur as

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Surface oxidation mechanism of a refractory high-entropy ...

2019-5-9  As these refractory alloys are potentially useful for operations in high temperature environments, knowledge of their oxidation behavior is required to develop oxidation-resistant

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ACID PRESSURE OXIDATION OF REFRACTORY GOLD

1987-1-1  ACID PRESSURE OXIDATION OF REFRACTORY GOLD MINERAL CARRIERS G.P. Demopoulos and V . G . Papangelakis Department of Mining and Metallurgical Engineering McGill U n i v e r s i t y , Montreal, Quebec, Canada H3A 2A7 ABSTRACT Acid pressure oxidation is c u r r e n t l y strongly advocated as the most e f f e c t i v e pre treatment method f o r r e f r a c t o r y gold ores

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Pressure Oxidation of a Refractory Sulfide Concentrate and ...

2018-8-11  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

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PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE

2012-10-4  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.

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Pressure Oxidation Process - Metso Outotec

Outotec can provide a complete pressure oxidation plant including all auxiliary processes for refractory gold sulfide oxidation. Gold is efficiently released from the sulfide matrix for the subsequent leaching process, whether cyanidation or chloride leaching. The Outotec pressure oxidation main process steps: Carbonate and chloride removal.

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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 ...

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Surface oxidation mechanism of a refractory high-entropy ...

2019-5-9  The oxidation process on the (001) surface of the refractory [(Mo 1−z W z) 0.85 Ta 0.10 (TiZr) 0.05 (z = 0.5)] HEA alloy is examined. The SQS method is used to generate random solid solution ...

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Selective oxidation of refractory sulfur compounds for

2013-2-26  pressure within residence time of 30 min. Hydrogen peroxide con-sumption to make peroxyacetic acid corresponds to half of the total operating cost. After the oxidation step, sulfone separation was con-ducted through liquid/liquid extraction to raffinate fraction with lower sulfur amount and extract fraction with high sulfur concentration.

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Developments in the pretreatment of refractory gold ...

2009-11-20  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 pressure nitric acid oxidation process is shown in Figure 2.

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Recovery Refractory Resources - SGS

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 create sulphur dioxide (SO 2) gas in the case of roasting, or sulphate ions in pressure oxidation and bio-oxidation. The iron component is

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A FUNDAMENTAL STUDY OF THE ACIDIC PRESSURE

2020-8-11  developed to represent the pressure oxidation of pyrite in the system studied at high temperature, based on the batch experimental data, which can be used to further develop a mathematical model to simulate continuous autoclave oxidation. During the acidic pressure oxidation of mixtures of pyrite and orpiment, As(III)

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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).

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Oxidation of refractory metals in air and low pressure ...

2000-1-1  Oxidation rate: Weight change vs time data for V–4Cr–4Ti at 400 and 500°C are shown in Fig. 1. At low pressures, weight changes were very low at 400°C up to 100 h (linear rates were in the range 10 −4 mg/cm 2 /h). In air, the data best fit a logarithmic time dependence .At 500°C, weight changes were an order of magnitude higher than at 400°C and data at low pressures were nearly a ...

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Pressure oxidation of double refractory raw materials in ...

Pressure oxidation allows to carry out the efficient processing of goldbearing sulfide materials. However, application of this method for processing of double refractory raw materials leads to irreversible gold losses due to autoclave preg-robbing of gold by organic carbon. Thermodynamic and experimental data indicate that almost complete sulfide decomposition leads to a high value of ...

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Selective oxidation of refractory sulfur compounds for

2013-2-26  pressure within residence time of 30 min. Hydrogen peroxide con-sumption to make peroxyacetic acid corresponds to half of the total operating cost. After the oxidation step, sulfone separation was con-ducted through liquid/liquid extraction to raffinate fraction with lower sulfur amount and extract fraction with high sulfur concentration.

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An oxidation resistant refractory high entropy alloy ...

2019-5-13  Although refractory high entropy alloys (RHEAs) have shown potentials to be developed as structural materials for elevated temperature applications, most of the reported oxidation behaviours of ...

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Developments in the pretreatment of refractory gold ...

2009-11-20  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 pressure nitric acid oxidation process is shown in Figure 2.

Get Price

Recovery Refractory Resources - SGS

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 create sulphur dioxide (SO 2) gas in the case of roasting, or sulphate ions in pressure oxidation and bio-oxidation. The iron component is

Get Price

A FUNDAMENTAL STUDY OF THE ACIDIC PRESSURE

2020-8-11  developed to represent the pressure oxidation of pyrite in the system studied at high temperature, based on the batch experimental data, which can be used to further develop a mathematical model to simulate continuous autoclave oxidation. During the acidic pressure oxidation of mixtures of pyrite and orpiment, As(III)

Get Price

Refractory Gold Ore Treatment Methods

2016-7-14  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

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TECHNOLOGY FOR PROCESSING OF REFRACTORY GOLD

2017-12-20  processes. In our opinion sulphide atmospheric oxidation processes are the most interesting as oxidation there runs without high temperature (up to 100 оС) and excess pressure (open units), and with acid environment close to neutral. The process of

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