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  • A clean and efficient leaching process for chromite ore

    2014-6-1 · In order to improve the chromate salts cleaner production technology, a pressure leaching process for chromite ore in 50 wt% KOH solution was studied for the first time and the results were presented in this manuscript. It was found out that the chromium extraction rate increased significantly with the increase of temperature and oxygen partial pressure, and the kinetics study confirmed that

    A clean and efficient leaching process for chromite ore

    In industry, chromite is firstly converted to chromate solution (such as Na 2 CrO 4 or K 2 CrO 4) by soda ash roasting and leaching. Then, the chromate is converted to Cr 2 O 3 by acidification and...

    Process for Chromite MDPI

    2019-1-28 · acid treatment process: (i) the chromium in the chromite is difficult to leach because of the high stability of the chromite spinel in sulfuric acid solution at room temperature and atmospheric pressure; (ii) iron, magnesium, and aluminum ions can be released into the leachate concomitantly as chromium is leached, and the removal of impurities is

    Mineral processing: leaching process of chromium

    2019-5-6 · Influence of leaching agent and contact time of the chromite roast The effect of various leaching agents e.g. boiled H 2 O, HCl (1.0 mol L −1) and H 2 SO 4 (1.0–7.5 mol L −1) and contact time (4–10 h) on the recovery of Cr, Al, Ni, and PGEs was carried out on the chromite roasted at

    leaching processleaching process for chromite

    Leaching is the process of a solute becoming detached or extracted from its carrier substance by way of a solvent.. Leaching is a naturally occurring proce (PDF) Leaching Mechanisms of Cr(VI) from Chromite

    Leaching of Valuable Elements from the Waste Chromite

    2020-8-11 · from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2

    (Bio)leaching Behavior of Chromite Tailings

    The beneficiation process majorly consists of comminution to physically liberate the minerals followed by physical separation to generate the concentrate of the chromite

    Leaching of Valuable Elements from the Waste

    2020-10-20 · The COPR from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2 CO 3), and dolomite and calcining at high temperatures. This residue contains a large amount of calcium and a small amount of iron, aluminum, chromium, etc. However, the COPR from the non-calcium-roasting process always contains a higher amount of iron, aluminum, and

    A new metallurgical process for the clean utilization of

    2014-9-10 · The kinetics investigation indicates that the leaching process is controlled by surface chemical reaction. The activation energy of the chromite ore leaching process is 42.65 kJ/mol, and the reaction order with respect to oxygen partial pressure is determined as 0.737. An empirical rate equation was derived to describe the pressure leaching process.

    Sulfuric acid leaching of South African chromite. Part 1

    2014-7-10 · Experiments using this chromite lump were conducted at 160 °C for leaching durations of 1, 2, 3, 5, 10, 15, 20, 30, 45, 60, 75, 90 and 120 min. For studying the sulfate precipitation behavior during the leaching process, experiments at a higher temperature (190 °C) were conducted for 90 min using the experimental lump.

    Leaching of chromite ore in concentrated KOH by

    2017-5-4 · The leaching process of chromite ore is a typical LO reaction, and the oxygen mass transfer in the KOH sub-molten salt solution is a vital factor. In order to intensify the reaction, the catalytic effect of potassium nitrate was examined in previous studies [8]. It was found that the introduction of

    leaching processleaching process for chromite

    A clean and efficient leaching process for chromite ore In both methanol and water leaching steps, the parameters were solid/liquid (s/l) ratio (1/2, 1/3, 1/4 and 1/5), leaching time (10, 20 and 30 m. Sulfuric acid leaching kinetics of South African chromite

    Mineral processing: leaching process of chromium

    2019-5-6 · The current strategy reports the recovery of precious group metals (PGMs) from Na2CO3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under atmospheric O2. The influence of roasting temperature (960–1200 °C) and leaching agents (H2O, HCl, H2SO4) and their concentrations on the recovery of PGMs was studied. Chromite roast concentrates a reasonable percentage of

    Leaching of Valuable Elements from the Waste Chromite

    2020-8-11 · from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2 CO 3), and dolomite and calcining at high temperatures.15 This residue contains a large amount of calcium and a small amount of iron, aluminum, chromium, etc. However, the COPR from the non-calcium-roasting process always contains a

    The Leaching Characteristics of Chromite Ore

    2016-8-11 · This study reports on the leaching characteristics of COPR from the soda ash roasting process that contained 8,500 mg/kg of Cr(VI), indicating poor recovery during the leaching process. To this end, leaching with different extraction solutions was studied as a function of time. The DI water, 0.1M NaOH and 1M NaOH leaching results were similar

    Study on mechanisms of different sulfuric acid

    2017-9-5 · The extraction of chromate from chromite via the sulfuric acid leaching process has strong potential for practical use because it is a simple and environmentally friendly process. This paper aims to study the sulfuric acid leaching process using chromite as a raw material via either microwave irradiation or in the presence of an oxidizing agent.

    Leaching of hexavalent chromium from young chromite

    ground and roasted chromite ores. In the roasting process, insoluble trivalent chromium [Cr(III)] present in the ores oxidizes to soluble hexavalent Cr [Cr(VI)], which is then recovered by aqueous leaching for further processing (Burke et al., 1991). The technology dates back to 1845 and is still in

    Treatability of chromite ore processing waste by

    2018-2-15 · Developing treatment and disposal strategies and health-based clean-up standards for chromium containing wastes continues to be an important

    Study on mechanisms of different sulfuric acid leaching

    2019-10-16 · 3.2. Chromite leaching process in sulfuric acid Fig. 3 shows the change in the chromium leaching effi-ciency from chromite with various concentrations of sulfuric acid when the oxidizing agent was used. As shown in Fig. 3, with increasing sulfuric acid concentration, increasing tem-perature, and increasing reaction time, the leaching effi-

    Green manufacturing process of chromium

    2004-11-19 · In the process of carbonate leaching, the chromium‐containing residue after magnesium extraction can be used as iron ore or raw material in the cement industry . In addition, aluminum in chromite ore can be extracted and recovered in the green process as aluminum hydroxide [Al(OH) 3]. Thus, the comprehensive use of all valuable elements (Cr

    Treatability of chromite ore processing waste by

    2018-2-15 · Developing treatment and disposal strategies and health-based clean-up standards for chromium containing wastes continues to be an important

    Study on mechanisms of different sulfuric acid leaching

    2019-10-16 · 3.2. Chromite leaching process in sulfuric acid Fig. 3 shows the change in the chromium leaching effi-ciency from chromite with various concentrations of sulfuric acid when the oxidizing agent was used. As shown in Fig. 3, with increasing sulfuric acid concentration, increasing tem-perature, and increasing reaction time, the leaching effi-

    Long-Term Leaching Characteristics of Chromite Ore

    2016-8-11 · Long-Term Leaching Characteristics of Chromite Ore Processing Residue Using Synthetic Groundwater Phosphate Removal from Water Using Novel Fe2+-KMnO4 Process: Significant Role of In Situ–Formed Fe(III) Journal of Environmental Engineering August 2014 .

    roasting and leaching processess for chromium

    Leaching process for chromite YouTube. 9 Oct 2013 2 step leaching and roasting process chromite Chromite -- Wikipedia, the free encyclopedia. Chromite is an iron chromium oxide: FeCr 2 O Read more. Selective dissolution of copper from copper-chromium spent catalyst

    Leaching kinetics of acid-soluble Cr(VI) from chromite

    2011-4-26 · Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle

    LEACHABILITY OF CHROME FROM MAGNESIA

    2016-2-25 · leaching indicates super-saturation of the solution and precipitation of the products. INTRODUCTION The working lining of copper refining (anodic) furnace made of magnesia-chromite (MCr) refractory materials is exposed to high temperatures and aggressive slags. The fire refining process of copper is in term of

    Modeling Chromium Dissolution and Leaching from

    2005-12-30 · Therefore, knowledge of migration behavior and leaching rates of chromium through waste materials are of primary concern for environmentally sound management of hazardous wastes. Leaching rates of total Cr and Cr(VI) were studied experimentally using laboratory columns packed with COPR material produced by a sodium chromite plant.

    The Chromothermic Reduction of Chromite

    2011-1-15 · The Chromothermic Reduction of Chromite *Royal School of Mines, London. ChromOlhermic reduction is a new process for the utilization of ores and concentrates having low Cr/Fe ratios in the production ofconcentrates for low-carbonferro-alloys,pure chromic oxide, chromium metal, orchemicals. The process

    Reclamation of reactive metal oxides from complex

    2015-3-10 · Hydrothermal leaching of chromite In this process, the chromite concentrate is digested with a 60% wt NaOH solution at 250 °C under an oxygen atmosphere with a partial pressure of 3.2 MPa. The following reactions take place during this process: 56 MgSiO 3(s)

    Process for extraction of platinum group metals from

    A process for treating chromite-bearing ores to obtain useful mineral values, especially platinum group metal, therefrom wherein the ore is separated into magnetic and non-magnetic fractions; the non-magnetic fraction, containing a substantial portion of the platinum group metals, is concentrated and smelted to produce a metal layer containing platinum group metals; and the platinum group

    leaching with caustic of the chromite plant

    leaching with caustic of the chromite plant. leaching process for chromite. Leaching of Valuable Elements from the Waste Chromite Ore from the calcium roasting process is the residue of water leaching after mixing chromite sodium carbonate (Na 2 CO 3) and dolomite and calcining at high temperatures.15 This residue contains a large amount of calcium and a small amount of iron aluminum chromium etc.

    Long-Term Leaching Characteristics of Chromite Ore

    2016-8-11 · Long-Term Leaching Characteristics of Chromite Ore Processing Residue Using Synthetic Groundwater Phosphate Removal from Water Using Novel Fe2+-KMnO4 Process: Significant Role of In Situ–Formed Fe(III) Journal of Environmental Engineering August 2014 .

    Leaching kinetics of acid-soluble Cr(VI) from chromite

    2011-4-26 · Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle

    Preventing Chromium Leaching

    2018-8-19 · This report presents the results of research aimed at evaluating and preventing the leaching action that may result from the disposal of waste ferrous slags into landfills where they can be subjected to acid precipitation. Waste slag constitutes a large potential source of chromium contamination of ground waters, particularly under the enhanced leaching action of acid precipitation on waste

    green process of matallurgical chromite(2006年接受)_图文

    2011-10-30 · The traditional chromate production process used in China presently consists of three procedures: roasting of chromite ore, water leaching, and multi-stage evaporation and crystallization. In the process of roasting, chromite is mixed with sodium carbonate and a large amount of limestone and dolomite additives, and then calcined at 1200 °C in a rotary kiln. ?

    Reclamation of reactive metal oxides from complex

    2015-3-10 · Hydrothermal leaching of chromite In this process, the chromite concentrate is digested with a 60% wt NaOH solution at 250 °C under an oxygen atmosphere with a partial pressure of 3.2 MPa. The following reactions take place during this process: 56 MgSiO 3(s)

    chromite processing program Prominer (Shanghai)

    Chromite Beneficiation Process. Metallurgical ContentThe Problem with Chromite ProcessingThe Chromite Extraction FlowsheetChromite Ore CrushingChromite GrindingGravity Recovery SectionChromite Process Summary The Problem with Chromite Processing Experience indi es that chrome ores are concentrated to best advantage by gravity methods.

    Process for extraction of platinum group metals from

    A process for treating chromite-bearing ores to obtain useful mineral values, especially platinum group metal, therefrom wherein the ore is separated into magnetic and non-magnetic fractions; the non-magnetic fraction, containing a substantial portion of the platinum group metals, is concentrated and smelted to produce a metal layer containing platinum group metals; and the platinum group

    The production process of chromite sand HAIXU

    2020-4-24 · Chromite Chromite ore is predominantly used in the production of ferrochrome an alloy of chrome and iron containing between The production process of chromite sand Read More »

    (PDF) 2001 effect of pH on Cr leaching from CPR

    2001 effect of pH on Cr leaching from CPR (Weng).pdf. Download. 2001 effect of pH on Cr leaching from CPR (Weng).pdf