pressure oxidation of nickel

High Temperature Pressure Oxidation of a Low-Grade

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

High Temperature Pressure Oxidation of a Low-Grade

2020-3-9 · 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

High Temperature Pressure Oxidation of a Low-Grade

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.

On the high-temperature oxidation of nickel - ScienceDirect

2003-1-1 · In a rather extensive investigation of nickel oxidation from 600 to 1200 °C, Graham et al.,,, focused on the sub-parabolic kinetics, and compared variations in the instantaneous parabolic rate constant and the oxide morphology with time for several different surface pretreatments, as well as for different annealing procedures prior to the oxidation.

High Temperature Pressure Oxidation of a Low-Grade

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

Oxidation of nickel and transport properties of nickel ...

2004-10-1 · 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 ...

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

Undoped NiO. 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 ...

Pressure oxidation overview - ScienceDirect

2005-1-1 · Pressure oxidation refers to the oxidation of sulfides, such as pyrite [FeS2] and marcasite [FeS2], at elevated temperature and pressure. Oxidation releases encapsulated gold grains from the sulfides and makes the oxidation residue of the ore or concentrate more amenable for gold recovery by cyanidation in a subsequent leaching step.

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

2020-8-6 · A STUDY OF OXIDATION KINIQICS OF NICKEL METAL IN FLOWING AIR AND OXYGEN-NITROGEN MI-S By D. J. Progar and B. W. Lewis Langley Research Center A study was made of the oxidation kinetics of nickel metal sheet in flowing air and in oxygen-nitrogen mixtures of varying composition.The study covered the temperatures 1500° F, 17>0° F, 2000° F, 2250° F, and 2500° F

Scaleup of pressure oxidation processes | SpringerLink

2016-11-1 · 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. The initial task involves developing one or more conceptual flowsheets, including the POX autoclave and downstream purification and recovery steps. A laboratory program is

High Temperature Pressure Oxidation of a Low-Grade

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.

High‐Pressure Oxidation of Metals, Nickel in Oxygen -

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

The Effect of Elevated Air Pressure on the Oxidation ...

2019-2-1 · pressure. Work by Baur, Bartlett [14] on pure nickel found that the oxidation rate of nickel is insensitive to pressure above atmospheric pressure. However, on advanced alloys under CO 2 atmospheres Pint, Brese [15] found a complex dependence on pressure in that alloys of

Characterization of oxide structures formed on nickel ...

Low pressure oxidation studies of Ni-18%Cr alloy were carried out at temperatures of 500–600°C for very brief periods. Detailed XPS, AES, SEM, and TEM studies identified four stages in the initial oxidation. These are: (1) formation of a mixed nickel-chromium oxide overlayer; (2) growth of submicron-sized oxide nodules; (3) development of dark “hole-like” patches on the surface; and (4 ...

Scaleup of pressure oxidation processes | SpringerLink

2016-11-1 · 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. The initial task involves developing one or more conceptual flowsheets, including the POX autoclave and downstream purification and recovery steps. A laboratory program is

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

2020-8-6 · A STUDY OF OXIDATION KINIQICS OF NICKEL METAL IN FLOWING AIR AND OXYGEN-NITROGEN MI-S By D. J. Progar and B. W. Lewis Langley Research Center A study was made of the oxidation kinetics of nickel metal sheet in flowing air and in oxygen-nitrogen mixtures of varying composition.The study covered the temperatures 1500° F, 17>0° F, 2000° F, 2250° F, and 2500° F

High Pressure Acid Leach & Pressure Oxidation

2016-12-20 · 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.

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).

Surface oxidation of nickel base alloys and stainless ...

2021-7-3 · paper investigates the oxidation kinetics on nickel-based alloys (Inconels 600 and 625) and on stainless steel 310, using a laser or a furnace preheating on small metallic parts. The scope of the study is the oxidation step taking place before the heating of the sample up to its ignition temperature.

Pressure Oxidation - Caldera Engineering

Pressure Oxidation (POX) is a process used to extract gold, copper, zinc, molybdenum, and uranium from refractory ore bodies. The POX process utilizes elevated temperatures (roughly 230 degrees Celsius), elevated pressures (roughly 35 bar or 510 psi), and

High‐Pressure Oxidation of Metals, Nickel in Oxygen -

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

Effect of Oxygen Pressure on Internal Oxidation of Nickel ...

2013-1-1 · 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.

Characterization of oxide structures formed on nickel ...

Low pressure oxidation studies of Ni-18%Cr alloy were carried out at temperatures of 500–600°C for very brief periods. Detailed XPS, AES, SEM, and TEM studies identified four stages in the initial oxidation. These are: (1) formation of a mixed nickel-chromium oxide overlayer; (2) growth of submicron-sized oxide nodules; (3) development of dark “hole-like” patches on the surface; and (4 ...

(PDF) The effect of elevated air pressure on the oxidation ...

2017-10-17 · of elevated air pressure on the oxidation properties of the nickel-based superalloy, RR1000, at 650°C with different surface modifications, Materials at High Temperatures, 35:1-3, 130-140, DOI ...

THE APPLICATION OF THE CESL NICKEL PROCESS TO

2015-11-20 · In 1995, CESL commenced benchscale testwork on pressure oxidation of nickel-copper-cobalt sulphide concentrates. Initial results were favourable, and a flowsheet was developed. Additional unit operations were built at the copper pilot plant in early 1996 to allow for nickel – cobalt recovery and a campaign was run in the last half of 1996.

Determination of the Nickel/Nickel Oxide Phase Transition ...

2014-11-12 · These values are quite similar to those reported for the oxidation of nickel obtained from thermodynamic tables with a ΔH° 298 of 46,100 J/mol and a ΔS° 298 of 68.0 J/mol K. 20 The fit agrees very well with exposure data in subcritical water, but not as well in supercritical water. The decrease in the fugacity at the SCW transition and ...

Pressure Oxidation - Caldera Engineering

Pressure Oxidation (POX) is a process used to extract gold, copper, zinc, molybdenum, and uranium from refractory ore bodies. The POX process utilizes elevated temperatures (roughly 230 degrees Celsius), elevated pressures (roughly 35 bar or 510 psi), and

Influence of the Oxygen Partial Pressure on the Oxidation ...

2010-8-24 · Low Partial Pressure: 10 −5 mbar. Tests have been carried out at 4 different oxidation times: 1, 24, 96 and 140 h. SEM Imaging. Observation of the oxide surface of the different samples shows nodule-shape structures that grow with increasing oxidation time, covering the entire surface (Fig. 2).EDX mapping showed that the oxide layer is continuous: the metal surface is covered with oxide and ...

Pressure Acid Leaching of Nickel Laterites: A Review

High-pressure acid leaching is a typical process employed for extracting nickel and cobalt from limonitic laterite. Because of the high iron content, this process requires a high temperature and ...

PRESSURE LEACHING - RPMGlobal

2020-1-22 · Sulfide Pressure Oxidation Pressure leaching of sulfide ores is complicated by many items such as sulfur viscosity and the passivation of reactive surfaces. “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.

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