pressure oxidation of sulphides

Hydrogen Sulfide Oxidation and Sewer Corrosion

7 Description of the hydrogen sulfide induced corrosion of concrete sewer systems - a new approach In pressure pipes where the DO concentration is zero in the wastewater phase, due to lack of reaeration, the sulfide cannot be oxidized and it diffuses from the biofilm into the liquid phase, as illustrated by the dotted arrow in Figure 1

AutoclaveTechnology- Applications for Sulphide ,

• Sherritammoniacalnickel sulphide concentrate leac h • Xstrata Nikkelverk matte chloride leach • Laterite leaching (Moa bay, Goro, Murrin Murrin) • SherritSulphuric acid matte leach (RSAbase metal ops) • Norilsk pyrrhotite leach • Refractory gold full pressure oxidation • Kidd Zinc pressure leach • ChambishiMetals cobalt .

Pressure oxidation of double refractory gold concentrates

Nevertheless, the pressure oxidation of double refractory materials containing carbonaceous matter in addition to sulfides results in substantial gold losses due to autoclave preg-robbing

PRESSURE LEACHING - RPMGlobal

Sulfide Pressure Oxidation Pressure leaching of sulfide ores is complicated by many items such as sulfur viscosity and the passivation of reactive surfac “Low” temperature conditions (100o C to 140o C) are generally not used in sulfide pressure leaching as this temperature range is conducive to formation of liquid elemental sulfur

Pressure oxidation leaching of chalcopyrite Part I ,

1 Introduction High temperature (200–230 °C) acid pressure oxidation leaching of metal sulfides was first commercialized in the 1950's However, the more recent commercial success of medium temperature pressure oxidation of zinc sulfide concentrates and high temperature pressure oxidation of refractory gold ores and concentrates has contributed to renewed interest in the total oxidative .

Sulphide Flotation - an overview | ScienceDirect Topics

Pressure-oxidation conditions were 225 °C, pulp density was 11%, retention time was 120 min, and oxygen overpressure was 689 kPa The ore treated had a P80 of 15 μm After solid–liquor separation, the gold and PGMs were recovered by sulfide precipitation using NaHS or by activated carbon

Fundamental study of silver deportment during the pressure ,

Aug 01, 2003· In this work, pressure oxidation of silver sulphide was investigated in the temperature range of 110–150 °C and in the sulphate media The subsequent deportment of silver was monitored to shed light on the path of aqueous silver Silver sulphide reacts during the pressure oxidation and silver is released into the solution

Scaleup of Pressure Oxidation Processes

Jan 01, 2016· "The successful commercialization of a pressure oxidation (POX) process for recovering metal values, including gold, copper, zinc, nickel and molybdenum, is the result of a carefully planned development program

PRESSURE OXIDATION OF PYRITE-ARSENOPYRITE ,

Pressure oxidation of pyrite-arsenopyrite refractory gold concentrate 103 Autoclave oxidation tests were conducted in Büchi ecoclave model 075 titanium autoclave The total volume of the autoclave vessel was about 11 dm3 and it was equipped with magnetic agitation unit, gas inlet and outlet, and sampling system with

Measurement of reaction enthalpy during pressure oxidation ,

Mar 12, 2009· A calorimetric method for determining the enthalpy of the aqueous oxidation of sulfide minerals at high temperatures and oxygen pressures has been developed and evaluated under conditions relevant to industrial pressure oxidation operations This information is important for heat balance calculation and optimization of the pressure reactor design

MAZZEI TECHNICAL BULLETIN No 3

MAZZEI TECHNICAL BULLETIN No 3 REMOVAL OF HYDROGEN SULFIDE BY AERATION It is a straight forward task to determine the theoretical amount of air which is required to oxidize and precipitate hydrogen sulfide from water The actual amount of air can then be estimated quite accurately so as to determine the correct Mazzei Injector to use and the

Sulfide - Wikipedia

Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S 2− or a compound containing one or more S 2− ions Solutions of sulfide salts are corrosive Sulfide also refers to chemical compounds large families of inorganic and organic compounds, eg lead sulfide and dimethyl sulfide Hydrogen sulfide (H 2 S) and bisulfide (SH −) are the conjugate .

Scaleup of Pressure Oxidation Processes - onemineorg

Jan 01, 2016· "The successful commercialization of a pressure oxidation (POX) process for recovering metal values, including gold, copper, zinc, nickel and molybdenum, is the result of a carefully planned development program

Autoclave and Pressure Oxidation | Mining and Minerals ,

Pressure oxidation was developed for processing refractory ores where gold is occluded in the sulfide minerals, typically pyrite or arsenopyrite Oxidation of the sulfides at elevated temperatures and pressures liberates the gold, allowing it to be economically recovered by conventional circuits

Outotec Pressure Oxidation – More out of Sulfide Ore - AusIMM

The addition of pressure oxidation equipment to Outotec’s product portfolio adds to and complements already existing significant experience in general hydrometallurgical process and proprietary equipment design and supply , pressure oxidation – more out of sulfide ore, in Proceedings World Gold 2013, pp 197-206 (The Australasian .

The Rise of Nickel Laterites and Advances in Sulphide ,

Sulphide Hydrometallurgy - POX • Process: − Comminution − Atmospheric chloride pre-leach − Pressure Oxidation leach >Pure oxygen >22-27 bar >200oC − Impurity precipitation - MHP product • Projects: − Voisey’s Bay, Canada, 50 ktpa finished nickel Pros Problems Can process arsenic-bearing ores Chlorine gas handling No SO 2

Pyrophoric Control - FQE Chemicals

One common way of dealing with pyrophoric iron is to intentionally oxidize the sulphide anion into the sulphate by adding caustic permanganate Potassium permanganate is a strong oxidizing agent, and the oxidation is catalyzed with caustic soda This is the same oxidation reaction of oxygen with iron sulphide that already causes so much concern

The Oxidation of Sulphide in Aqueous Solutions

carbon as a catalyst on the initial sulphide oxidation rate in order to investigate whether the oxidation of sulphide can be realized in a continuous process at high pH values, a relatively low temperature and with air at atmospheric pressure 2 MECHANISM The oxidation of sulphide in water by oxygen

Gold Sulphide Ore Oxidation by Alkaline Pressure

Iron sulphide minerals break down completely during pressure oxidation, and dissolve in the sulphuric acid solution that is generated from oxidation of the sulphid This liberates the tiny gold particles that were originally trapped in the sulphide crystals, and gold recovery during subsequent cyanidation is usually very high (>95%)

Characterization of Residue from the Pressure Oxidation ,

A bulk sulfide flotation process followed by oxidation pressure leaching resulted in high extractions (>98 %) of the copper and nickel in the flotation concentrate During the leaching, the iron in the flotation concentrate leaches and precipitates as either hematite (crystalline or amorphous) or as a basic iron sulfate (jarosite) .

Unlocking Disseminated Nickel Sulphides using the CESL ,

Unlocking Disseminated Nickel Sulphides Using the CESL Nickel Process By David L Jones, Keith Mayhew, Rob Mean and Mary Neef , sulphide resources will continue to be an integral source of primary nickel supply going forward , The CESL Nickel Process uses similar pressure oxidation (PO) conditions to the CESL Copper

The effects of pressure and temperature on the catalytic ,

The effects of pressure and temperature on the catalytic oxidation of hydrogen sulfide in natural gas and regeneration of the catalyst to recover the sulfur produced Authors Ajay K Dalai.

The Mechanism of the Catalytic Oxidation of Hydrogen Sulfide

The kinetics of the catalytic oxidation of hydrogen sulfide by molecular oxygen have been studied in the temperature range 20-250°C The primary reaction product is sulfur which may undergo further oxidation to SO9 at temperatures above 200°C From the kinetics of this autocatalytic reaction we derived an oxidation-reduction mecha- nism

CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING OF ,

Chloride–hypochlorite oxidation and leaching of refractory sulfide gold concentrate 63 Fig 1 The Pourbaix diagram of Fe–S at [Fe] –= 10 4 M, [S] = 10– M and 25 C (the chlorine species regions are also marked) (Marsden and House, 2005) Fig 2

High Pressure Acid Leach & Pressure Oxidation

Pressure Oxidation (POX) It is well know that sulphide minerals decompose rapidly in acidic media under conditions of elevated pressure and temperature using oxygen as the principal oxidation agent This so called “chemical liberation” will allow for the liberation of metals encapsulated

Measurement of reaction enthalpy during pressure oxidation ,

A calorimetric method for determining the enthalpy of the aqueous oxidation of sulfide minerals at high temperatures and oxygen pressures has been developed and evaluated under conditions relevant to industrial pressure oxidation operations This information is important for heat balance calculation and optimization of the pressure reactor design

Alacer Plans Development of Çöpler Sulphides | E & MJ

Alacer will take a phased approach to the development of pressure oxidation processing of the Çöpler sulphides, starting with a definitive feasibility study (DFS) of a 5,000-mt/d plant that can be scaled up in the future if conditions warrant The company expects to complete the DFS no later than June 2014

Pressure oxidation of pyrite-arsenopyrite refractory gold ,

Pressure oxidation processes are difficult to perform because valuable high-pressure and high-temperature equipment are required If the sulfide sulfur content is above 30%, there is no cost .

Pressure Oxidation of a Refractory Sulfide Concentrate and ,

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 impuriti Normally, gold is extracted from neutralized autoclave leach residue by cyanidation

KINETICS AND MECHANISM OF ARSENIC SULFIDES ,

sublimation of remaining arsenic sulfides and their oxidation in the gaseous phase, and the second one is corresponding to oxidation of FeS2 to Fe2O3 According to the Borchard and Daniels method, activation energies of arsenic sulfide mixture oxidation process, described above, are placing all the reactions in the kinetic area

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