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pressure oxidation of nickel

High Temperature Pressure Oxidation of a Low-Grade Nickel ...

In the present study, a high iron, low nickel concentrate was treated by pressure oxidation at 250C, albeit a somewhat higher temperature than typically employed, to demonstrate some of the benefits and shortcomings of this approach. Alternative methods to mitigate some of the shortcomings

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High Temperature Pressure Oxidation of a Low

The pressure oxidation of 9.2% w / w “aged” nickel concentrate at 250 °C as a function of time, with 100 kPa O 2 overpressure and maximum oxygen flow rate of ~1.2 L/min., was investigated several years after the initial tests.

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High Temperature Pressure Oxidation of a Low

The pressure oxidation of low-grade nickel sulfide concentrate with high iron sulfides content generates significant amounts of sulfuric acid that must be neutralized.

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High Temperature Pressure Oxidation of a Low

High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for higher grade concentrates. This results in the formation of basic iron sulfate phases and a significant amount of sulfuric acid.

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Oxidation of nickel and transport properties of

01-10-2004  Oxidation kinetics of high purity nickel, as well as the nonstoichiometry and chemical diffusion in nickel oxide have been studied as a function of temperature (1373–1673 K) and oxygen pressure (10–10 5 Pa) using microthermogravimetric techniques.

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High Temperature Pressure Oxidation of a Low-Grade Nickel ...

Nickel concentrate (received dry) from Poseidon Nickel Limited (Subiaco, WA, Australia) was screened to 75 m to generate the sulfidic feed material. Pressure oxidation was conducted at 250 C using a 1 gallon titanium Parr autoclave with a dual pitched blade impeller driven at a speed of 750 rpm

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High Temperature Pressure Oxidation of a Low

High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for higher grade concentrates. This results in the formation of basic iron sulfate phases and a significant amount of sulfuric acid.

More

High‐Pressure Oxidation of Metals, Nickel in

adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A

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Oxidation of nickel and transport properties of

Oxidation kinetics of high purity nickel, as well as the nonstoichiometry and chemical diffusion in nickel oxide have been studied as a function of temperature (1373–1673 K) and oxygen pressure (10–10 5 Pa) using microthermogravimetric techniques. In order to eliminate the possible participation of grain boundary diffusion in scale growth at lower temperatures, the oxidation rate ...

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High Pressure Acid Leach Pressure Oxidation

Uranium Nickel Gold Copper Cobalt Rare earths Zinc 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.

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The oxidation kinetics of thin nickel films between

Nickel oxide (Ni 1− δ O) is a metal-deficient p-type semiconductor which is thermodynamically stable in a large temperature (T) and oxygen partial pressure (p O 2) range. 20 Nickel vacancies and electron holes (h˙) are predominant defects, but the ionization degree of nickel vacancies (singly ionized: or doubly ionized: using the Kröger–Vink notation 21) in the temperature and partial ...

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Nickel - Wikipedia

Nickel is a silvery-white metal with a slight golden tinge that takes a high polish. It is one of only four elements that are magnetic at or near room temperature, the others being iron, cobalt and gadolinium.Its Curie temperature is 355 °C (671 °F), meaning that bulk nickel is non-magnetic above this temperature. The unit cell of nickel is a face-centered cube with the lattice parameter of ...

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Jervois to integrate Pressure Oxidation Leach

Highlights - Flowsheet optimisation for Jervois’ São Miguel Paulista nickel-cobalt refinery determines integration of a pressure oxidation leach circuit - POX leach circuit will debottleneck ...

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Chemistry of Nickel - Chemistry LibreTexts

Nickel sulfides consist of NiS 2, which has a pyrite structure, and Ni 3 S 4, which has a spinel structure.. All the nickel dihalides are known to exist. These compounds are usually yellow to dark brown in Color. Preparation directly from the elements is possible for all except NiF 2, which is best prepared from reaction of F 2 on NiCl 2 at 350°C. Most are soluble in water and crystallization ...

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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.

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High Temperature Pressure Oxidation of a Low

High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for higher grade concentrates.

More

Effect of Oxygen Pressure on Internal Oxidation

The oxidation behavior of solid-solution nickel-aluminum alloys was studied at four levels of oxygen pressure ranging from a partial pressure of 10 −4 atmosphere to a total pressure of 10 atmospheres. Three such alloys containing 1.04, 3.90, and 6.40 atomic percent (a/o) Al were oxidized at 1000 C for times of 6.25, 25, and 100 hours.

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A study of oxidation kinetics of nickel metal in flowing ...

Wagner theory, the reaction-rate constants for nickel oxidation should be depend- ent on the one-sixth root of the oxygen partial pressure ( po $I6) and some (See ref. 7.) If this parabolic mechanism is correct, one would not expect that the flow of oxidizing gas over

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Nickel - Wikipedia

Nickel is a silvery-white metal with a slight golden tinge that takes a high polish. It is one of only four elements that are magnetic at or near room temperature, the others being iron, cobalt and gadolinium.Its Curie temperature is 355 °C (671 °F), meaning that bulk nickel is non-magnetic above this temperature. The unit cell of nickel is a face-centered cube with the lattice parameter of ...

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Chemistry of Nickel - Chemistry LibreTexts

In the first step of the process, nickel oxide is reacted with water gas, a mixture of H 2 and CO, at atmospheric pressure and a temperature of 50 °C. The oxide is thus reduced to impure nickel. Reaction of this impure material with residual carbon monoxide gives the toxic and volatile compound, nickel tetracarbonyl, Ni(CO) 4 .

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The oxidation kinetics of thin nickel films between 250 ...

Undoped NiO. Nickel oxide (Ni 1 dO) is a metal-deficient p-type semiconductor which is thermodynamically stable in a large temperature (T) and oxygen partial pressure (pO 2) range.20 Nickel vacancies and electron holes (h ) are predominant defects, but the ionization degree of nickel vacancies (singly ionized: V0 Ni or doubly ionized: V 00

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Characterization of Residue from the Pressure

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).

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High Pressure Acid Leach Pressure Oxidation

Uranium Nickel Gold Copper Cobalt Rare earths Zinc 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.

More

Thermodynamic modeling of pressure

In this article, HSC Chemistry 6 software (Equilibrium Composition module) was used to create thermodynamic prediction of pressure oxidation leaching of copper-nickel converter matte in sulfuric acid media. A synthetic sample of the material was prepared by admixture of copper-nickel mattes and nickel plants semi-products.

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Pressure Oxidation of a Refractory Sulfide

Significant advances have taken place in the treatment of refractory gold ores and concentrates during the past decade. In sulfide ores, pyrite is the most common host mineral for gold. Studies by Gasparrini (1983) showed that gold occurs in pyrite as native gold or electrum in all sizes and forms. Arsenopyrite is probably the second most common host for gold and forms similar associations ...

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High Temperature Pressure Oxidation of a Low

High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for higher grade

More

Characterization of Residue from the Pressure

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).

More

Enhanced Oxidation of Nickel at Room Temperature by Low ...

Enhanced Oxidation of Nickel at Room Temperature by Low-energy Oxygen Implantation . Robert Peter, Iva Šarić, ... Langmuir, connected to the gas pressure (in Pa) and the ex-posure time (in seconds) as 1 L = 1.3 3×10–4 Pa s. The ion-beam oxidation was also carried out in situ with a broad

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XPS study of oxides formed on nickel‐base alloys

The aim of this work is to characterize the oxidation behaviour of different nickel‐base alloys exposed to high‐temperature and high‐pressure water for short oxidation times. The behaviour of Alloy 600 (74% Ni, 16% Cr, 9% Fe), Alloy 690 (60% Ni, 30% Cr, 9% Fe) and Alloy 800 (47% Fe, 32% Ni, 21% Cr) exposed to simulated, pressurised water reactor primary water at 325°C has been compared.

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Thermodynamic modeling of pressure oxidation

Thermodynamic modeling of pressure oxidation leaching of copper-nickel converter matte Translated title of the contribution L. G. Elfimova , N. G. Ageev , S. S. Naboychenko

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Characterization of oxide structures formed on

OSTI.GOV Journal Article: Characterization of oxide structures formed on nickel-chromium alloy during low pressure oxidation at 500-600 degree C

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Thermodynamic modeling of pressure

In this article, HSC Chemistry 6 software (Equilibrium Composition module) was used to create thermodynamic prediction of pressure oxidation leaching of copper-nickel converter matte in sulfuric acid media. A synthetic sample of the material was prepared by admixture of copper-nickel mattes and nickel plants semi-products. According to rational composition of the material and stoichiometric ...

More

Chemistry of Nickel - Chemistry LibreTexts

Nickel sulfides consist of NiS 2, which has a pyrite structure, and Ni 3 S 4, which has a spinel structure.. All the nickel dihalides are known to exist. These compounds are usually yellow to dark brown in Color. Preparation directly from the elements is possible for all except NiF 2, which is best prepared from reaction of F 2 on NiCl 2 at 350°C. Most are soluble in water and crystallization ...

More

Jervois to integrate Pressure Oxidation Leach

Jervois to integrate Pressure Oxidation Leach Circuit into SMP Refinery Highlights - Flowsheet optimisation for Jervois’ São Miguel Paulista nickel-cobalt refinery determines integration of a pressure oxidation (“POX”) leach circuit

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Mechanistic Investigation of Biomass Oxidation

Here, we successfully demonstrate anodic biomass oxidation by synthesizing 5 nm nickel oxide nanoparticles (NiO NPs). NiO NPs show a unique electrocatalytic activity for 5-hydroxymethylfurfural (HMF) oxidation under near-neutral conditions, exhibiting an anodic current onset (1 mA cm–2) at 1.524 V versus the reversible hydrogen electrode and a total Faradaic efficiency of ≤70%.

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