alkaline pressure oand idation of gold concentrates

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The gold concentrate bio-oxidation process is used on a large-scale in countries such as Australia Brazil Ghana Peru and South Africa Nearly all of these plants employ large continuous stirred bioreactors 1 2 Chile ranks 11th among the gold producing countries with a...

Tungsten extraction and processing

The common tungsten extraction methods are surface or open pit mining and sub-surface or underground mining or a combination of both Modern tungsten processing methods dissolve scheelite and wolframite concentrates by an alkaline pressure digestion and tungsten...

Effect of Pretreatment of Sulfide Refractory Concentrate

gen pressure of 80 psi 10 w/w sodium hypochlorite temperature of 80˚C at pH = 13 and a constant stirring speed of 600 rpm These conditions allowed an approximated 60 of gold and 90 of silver extractions in 1 hr Keywords Refractory Gold Concentrate Hypochlorite Ox idation Pretreatment Pressure Cyanidation 1 Introduction 11...

Recovery of gold from refractory ores and concentrates of

Oct 24 2000 0183 32 What is claimed is 1 A method increasing the leaching yield of gold in the cyanide treatment of refractory ores containing gold tellurides or concentrates of such ores while delivering air in an alkaline environment at atmospheric pressure comprising conducting the cyanide treatment at a temperature from 60 176 C to a temperature immediately beneath the boiling point of the leaching liqu...

The Simultaneous Oxidation Of Sulfide Minerals And The

The alkaline oxidation of refractory gold concentrates containing arsenopyrite and pyrite at ambient temperatures and pressures has been found to be accompanied by the simultaneous dissolution of gold without the addition of cyanide A detailed study has been made of the kinetics of the oxidation of the pure minerals and of several concentrat...

HYDROMETALLURGICAL PROCESSING OF GOLD

Jul 18 2013 0183 32 This paper outlines the application of the industrially proven technologies of low pressure and temperature Nitrogen Species Catalyzed NSC pressure leaching and Alkaline Sulphide Leaching ASL for the recovery of copper and gold from enargite Copper can be recovered as a cathode metal or as a clean concentrate suitable for smelting...

Oxidation of refractory gold concentrates and simultaneous

The leaching experiments also have shown that gold may dissolve in alkaline thioarsenite solutions which provides a possible new process option for the leaching of gold\ud \ud The oxidation of refractory arsenical gold concentrates in aerated alkaline solutions results in the formation of thiosulfate arsenate and sulfate as well as the...

Allied Nevada progresses with Ambient Pressure Alkaline

AAO as it is intended to be applied in the concentrate oxidation process for Hycroft involves using oxygen-enriched air and heat generated from the oxidation process to oxidise the concentrate in an ambient pressure environment using trona to provide the alkaline environment and to neutralise the acid that is created during the oxidation process...

Alkaline Pressure Oxidation of a Gold

Dec 01 1995 0183 32 TY - JOUR T1 - Alkaline Pressure Oxidation of a Gold-Bearing Arsenopyrite Concentrate AU - Hiskey J B PY - 1995/12/1 Y1 - 1995/12/1 N2 - The aqueous pressure oxidation of gold bearing arsenopyrite concentrates in alkaline solution was investigated as a function of O2 pressure and NaOH concentration...

WO2015171010A1

The invention relates to a process for the extraction of gold and silver from ores and mining by-products The process according to invention consists in treating ores and mining residues having a content of 05 12 ppm Au with a solution of ammonium thiosulphate recycled at a temperature of 15 - 25 176 C the filtrate resulting after solubilization is subjected to an electrolytic extraction...

Alkaline Pre

A new hydrometallurgical pre-oxidation process for the refractory gold arsenosulfide concentrates under normal temperature and pressure was presented It comprised fine grinding intensified agitation alkali-leaching cyanidation and adsorption In a stirring-type pulverizing-leaching tower mill the concentrate was ground to 37μm of 98 then the intensified alkaline leaching for 24 h by...

A fundamental study of the alkaline sulfide leaching of gold

been an increased interest in pressure oxidation as a means of treating gold bearing ores and concentrat One of the problems with the partial oxidation of the sulfide host matrix to form elemental sulfur is that sulfur containing streams are difficult to treat using cyanidation In the present paper the alkaline...

Arsenic Pyrite Gold Extraction by Alkaline Leaching Oxidation

Metallurgical ContentLeaching Chemistry and Process ConsiderationExperimental Procedures ElectrochemicalLeachingPrecious Metal ExtractionArsenic and Sulfur Separation...

Pressure cyanide leaching for precious metals recovery

A novel method demonstrates that the oxidation and dissolution of gold and silver in alkaline cyanide solution can be conducted simultaneously in the same autoclave in less than 90 minutes with a recovery that exceeds 96 Because mild operating conditions of 80 176 C and 06 MPa oxygen pressure are used in this process low cost materials of construction can be utilized for the autoclave...

oand idation of alcohols by mno2 with ball mill

Oand Idation Of Alcohols By Mno2 With Ball Mill oxidation of alcohols by mno2 with ball mill oand idation of alcohols by mno2 with ball mill mill molino vertical Crusher Machine vstorgin Shanghai MG is a young and dynamic factory exporting Grate Ball Mill Overflow Type Ball Mill Rubber Lined Ball Mill to oand idation of alcohols by mno2 with...

Biorecovery of gold

decreases with increasing size of the refractory gold concentrate particles 6 In Chile which produced 30 000 kg of gold in 1990 Thiobacillus ferrooxidans was used to recover gold from a complex ore under laboratory conditions9 The ore contained 82 Fe 078 Cu 088 As and 35 g Au/ton with pyrite...

Ch 30 Alterations of Renal and Urinary Tract Function SG

Dilation of a ureter by accumulated urine rapid removal of an upper urinary tract obstruction is important because the accumulating urine causes back pressure that ___ renal cells Kills You are making more urine than usual because your kidneys are not able to concentrate it due to functioning kidney tissue but dysfunctioning nephrons...

Gold processing

Gold processing - Gold processing - Mining and concentrating The nature of the ore deposit determines the mining and mineral processing techniques applied Oxide ore deposits are frequently of such low grade eg 3 to 10 parts per million that extensive mineral processing cannot economically be justified In this case they are merely shattered by explosives and then piled into heaps for...

Patents Assigned to Barrick Gold Corporation

Jan 29 2020 0183 32 Abstract The present invention relates to flotation of sulfidic copper-molybdenum- and gold-containing minerals More specifically the invention relates to sulfoxy reagent-assisted floatation for separating of sulfides of copper molybdenum and gold from pyrite marcasite pyrrhotite arsenopyrite and other gangue minerals following aerating by an oxidizing gas and contacting by a sulfoxy...

Extraction of Gold

When the gold has solidified the molten silver chloride collected on the surface is run off carrying with it a small proportion of gold When silver is the chief impurity in the gold as in that found in Australia the process is specially applicable The gold has a degree of purity of 991 to 997 per cent...

The development of an environmentally friendly leaching

An environmentally friendly leaching process consisting of the pretreatment of alkaline pressure oxidation and thiosulfate leaching has been developed to efficiently extract gold from a high carbon arsenic and antimony bearing sulfide gold concentrate The Au extraction from the concentrate by direct cyanidation was very low mainly due to the encapsulation of gold by associated minerals and...

Recovery of gold from refractory ores and concentrates of

Jul 02 2002 0183 32 What is claimed is 1 A method increasing the leaching yield of gold in the cyanide treatment of refractory ores containing gold tellurides or concentrates of such ores while delivering air in an alkaline environment at atmospheric pressure comprising conducting the cyanide treatment at a temperature from 60 176 C to a temperature immediately beneath the boiling point of the leaching liqu...

OXIDATION OF REFRACTORY GOLD CONCENTRATES AND

The oxidation of refractory gold concentrates containing arsenopyrite and pyrite and the simultaneous dissolution of gold in aerated alkaline solutions at ambient temperatures and pressures without the addition of cyanide has been studied It involves the following aspects the chemistry of the oxidation of pure arsenopyrite and pyrite...

Alkaline Oxidative Leaching of Gold

Alkaline pressure oxidation is not new it was first proposed by Sill 13 in the late 1950 s for treating arsenic sulfide ores and was used commercially for treating a cobalt-nickel arsenic ore 14 Alkaline pressure oxidation was also used to treat high-acid-consuming mercury gold ore 15...

The Albion Process for Refractory Gold

Where the main gold bearing refractory mineral in the concentrate is pyrite the oxidative leach is typically carried out under alkaline conditions The leach conditions are set to ensure the formation of goethite as the major iron reaction product The alkaline leach conditions accelerate the rate of...

Oxidation of refractory gold concentrates and simultaneous

The oxidation of refractory gold concentrates containing arsenopyrite and pyrite and the simultaneous dissolution of gold in aerated alkaline solutions at ambient temperatures and pressures without the addition of cyanide has been studied It involves the following aspects the chemistry of the oxidation of pure arsenopyrite and pyrite minerals in aerated alkaline solutions the kinetics of...

Flexicone technology for sulfide ores flexicone

The Intensive Leaching Units existing in the gold mining industry from reputable suppliers do not recover the claimed 98 of gold from gravity concentrates due to the presence of refractory and finely disseminated gold in minerals sulfides tellurides carbonaceous shales As the real practice shows the actual gold recovery is much lower and can be less than 50...

Alkaline Pressure Oxidation of a Gold

Apr 26 2007 0183 32 The aqueous pressure oxidation of gold bearing arsenopyrite concentrates in alkaline solution was investigated as a function of O2 pressure and NaOH concentration Dissolution of gold from the leach residue was accomplished by standard cyanidation Gold extraction was found to be proportional to the degree of arsenopyrite oxidation Alkaline pressure oxidation at 160 176 C 2413 kPa...

Emerging technologies in cyanidation of gold and silver a

in alkaline solution reducing the extraction of gold The usual process to recover gold from ores containing aurostibite is flotation pretreatment of the concentrate in aqueous solution with lead nitrate and leaching in a pipe reactor at 9 MPa oxygen pH 7 and 20 g/L NaCN...

PDF Alkaline Pressure Oxidation of a Gold

The aqueous pressure oxidation of gold bearing arsenopyrite concentrates in alkaline solution was investigated as a function of O2 pressure and NaOH concentration...