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Extraction of chromium from Egyptian chromite ores ...

1972-11-3  AbstractThe roasting process of Egyptian chromite middling product with lime and soda was successfully performed to produce sodium chromate with a chromium recovery of 97% and an aluminum recovery of 81%. The optimum conditions were determined. Separation of alumina from the chromatealuminate solution was achieved by controlling the pH of the solution at 7.6 by carbon dioxide gas.

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A Cr⁶⁺⁻ Free Extraction of Chromium Oxide from Chromite ...

2020-3-2  A Cr6+-FREE EXTRACTION OF CHROMIUM OXIDE FROM CHROMITE ORES USING CARBOTHERMIC REDUCTION IN THE PRESENCE OF ALKALI L. Escudero-Castejon, S. Sanchez-Segado, S. Parirenyatwa, Y. Hara, A. Jha The Institute for Materials Research, School

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A novel reductive alkali roasting of chromite ores for ...

A novel reduction reaction for extracting Cr 2 O 3 from chromite ores is demonstrated by excluding the formation of carcinogenic chromate (Cr 6+) intermediates.We have investigated in detail the underpinning high-temperature reduction reaction: FeCr 2 O 4 +Na 2 CO 3 +2[C]=[Fe]+Na 2 Cr 2 O 4 +3CO (g), which defines the process chemistry for the formation of sodium chromite (Na 2 CrO 2) as an ...

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Process for extracting chromium from chromium ores ...

The commonest of these ores is chromite, a natural oxide of iron and chromium, which in some cases contains oxides of magnesium, aluminum and silicon. Chromium is generally extracted from its ores by oxidation in the form of chromate, in which state its valence is six. The product of this reaction is then treated to extract the chromate.

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A Cr6+-Free Extraction of Chromium Oxide from Chromite ...

2017-2-8  A novel process for extraction of chrome oxides from chromite ores has been investigated. The process is based on the carbothermic reduction of chromite ore with solid carbon (activated charcoal) in the presence of an alkali in the temperature range of 950–1050 °C.

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Leaching of hexavalent chromium from young chromite ore ...

2020-3-18  Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills. The objective of this study was to investigate the leaching characteristics of hexavalent Cr [Cr(VI)] from two COPR samples obtained from unlined landfills in the Kanpur area of northern India.

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Effective Chromium Extraction from Chromium-containing ...

chromite ores result in the difference in Cr extraction mech-anism. In addition, discrepancies in oxidation mechamism of chromite ores in sodium roasting process and difference in physic-chemical properties between chromite and Cr-con-taining vanadium slag should not be ignored. Consequently, oxidation mechanism of chromium in this vanadium slag

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Leaching of hexavalent chromium from young chromite

derived from the extraction of chromate (CrO 4 2−)from 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 ...

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Comparative study of alkali roasting and leaching of ...

2016-10-1  Chromium extraction from chromite ore Chromium is present in many different minerals, nevertheless, just chromite ore, which can be expressed with the general formula (Fe a Mg (1 − a)) (Cr b Al (1 − b)) 2 O 4, is used for commercial extraction of chromium (Maliotis, 1996).

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Extraction of chromium from Egyptian chromite ores ...

1972-11-3  AbstractThe roasting process of Egyptian chromite middling product with lime and soda was successfully performed to produce sodium chromate with a chromium recovery of 97% and an aluminum recovery of 81%. The optimum conditions were determined. Separation of alumina from the chromatealuminate solution was achieved by controlling the pH of the solution at 7.6 by carbon

Get Price

introduction of processing of chromite ores introduction of

A Cr⁶⁺⁻ Free Extraction of Chromium Oxide from Chromite . Oxidative alkali roasting of chromite is the stateoftheart process for manufacturing chromiumcontaining chemicals, which involves dealing with serious environmental problems arising from handling Cr6+containing wastes generated in this process In this article a new method for the extraction of Cr2O3 from chromite ores is explained ...

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Leaching of hexavalent chromium from young chromite

2020-3-18  Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills. The objective of this study was to investigate the leaching characteristics of hexavalent Cr [Cr(VI)] from two COPR samples obtained from unlined landfills in the Kanpur area of northern India.

Get Price

Leaching of hexavalent chromium from young chromite

Chromite ore processing residue (COPR) is generated by the roasting of chromite ores for the extraction of chromium. Leaching of carcinogenic hexavalent chromium (Cr(VI)) from COPR dumpsites and ...

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Leaching of hexavalent chromium from young chromite

derived from the extraction of chromate (CrO 4 2−)from 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 ...

Get Price

Development of PGMs and Chrome Extraction Circuit

2012-5-23  extraction plant in the middle of the flotation circuit in order to ... UG-2 ore about 70 to 80% of the PGMs in UG-2 ores are typically associated with base metals sulphides (BMS) as occlusions and intergrowth [8]. ... removing the chromite fraction from the first rougher stage

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Comparative study of alkali roasting and leaching of ...

2016-10-1  Extraction of titanium and chromium oxides may be achieved via roasting the respective minerals with alkali at high temperatures, followed by water and organic acid leaching. In this study, sodium and potassium hydroxides are used as alkali for roasting of chromite ores

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Chromite Beneficiation Process

2016-4-12  Metallurgical ContentThe Problem with Chromite ProcessingThe Chromite Extraction FlowsheetChromite Ore CrushingChromite GrindingGravity Recovery SectionChromite Process Summary The Problem with Chromite Processing Experience indicates that chrome ores

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The impact of platinum production from UG2 ore on ...

2009-8-26  quantities of chromite with typically a chrome-to-iron (Cr/Fe) ratio of 1.35. UG2 ores can contain between 10 and 25% Cr2O3 depending upon the reef width and the selected mining method. It is relatively cheap and easy to extract a portion of the chromite from a platinum concentrator tailings stream at a grade of between 40–42% Cr2O3.

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LIST OF ORES AND THEIR NAMES SULPHIDE ORE

2021-5-27  from chromite (FeCr2O4 Cr2O3 FeO). By Chemical separation Some of the ores are concentrated by means of chemical treatment. Leaching : It involues the treatment of the ore with a suitable reagent. as to make it soluble while impurity remain insoluble. The ore is recoverd from the solution by suitable chemical method. (i) Bayer's process

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introduction of processing of chromite ores introduction of

A Cr⁶⁺⁻ Free Extraction of Chromium Oxide from Chromite . Oxidative alkali roasting of chromite is the stateoftheart process for manufacturing chromiumcontaining chemicals, which involves dealing with serious environmental problems arising from handling Cr6+containing wastes generated in this process In this article a new method for the extraction of Cr2O3 from chromite ores is explained ...

Get Price

Leaching of hexavalent chromium from young chromite ore ...

2020-3-18  Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills. The objective of this study was to investigate the leaching characteristics of hexavalent Cr [Cr(VI)] from two COPR samples obtained from unlined landfills in the Kanpur area of northern India.

Get Price

Chromite Beneficiation Process

2016-4-12  Metallurgical ContentThe Problem with Chromite ProcessingThe Chromite Extraction FlowsheetChromite Ore CrushingChromite GrindingGravity Recovery SectionChromite Process Summary The Problem with Chromite Processing Experience indicates that chrome ores

Get Price

Leaching of hexavalent chromium from young chromite

derived from the extraction of chromate (CrO 4 2−)from 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 ...

Get Price

Development of PGMs and Chrome Extraction Circuit

2012-5-23  extraction plant in the middle of the flotation circuit in order to ... UG-2 ore about 70 to 80% of the PGMs in UG-2 ores are typically associated with base metals sulphides (BMS) as occlusions and intergrowth [8]. ... removing the chromite fraction from the first rougher stage

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Method of production of chromite concentrate

The method of obtaining chromite concentrate is C poor chromium ores, includes grinding the ore, roasting, leaching acid circulating the filtrate, filtering the suspension, washing and drying the obtained chromite concentrate, characterized in that the calcining is carried out at a temperature of 500-550°, leaching, and filtration is carried out in two stages: the first stage of leaching lead ...

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Method of concentration of magnesia chromite ore

SUBSTANCE: chromite ores are raw material for production of ferro-chromium of various grades, of metallic chromium, of dyes and refractory materials. The method of concentration of magnesia chromite ore includes crushing of ore, oxidising roasting, cooling, crumbling and magnetic separation with production of chromite iron concentrate and iron ...

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Extraction of Metals: From Ores, Definition, Meaning, Examples

2021-6-23  The extraction of metals from their ores involves various steps. The steps depend on the type of ore, the reactivity of the metal, and the nature of impurities present in the ore. ... Chromite from siliceous gangue, rutile from chlorapatite, and wolframite from cassiterite are separated by this method. 4. Froth floatation process: ...

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The impact of platinum production from UG2 ore on ...

2009-8-26  quantities of chromite with typically a chrome-to-iron (Cr/Fe) ratio of 1.35. UG2 ores can contain between 10 and 25% Cr2O3 depending upon the reef width and the selected mining method. It is relatively cheap and easy to extract a portion of the chromite from a platinum concentrator tailings stream at a grade of between 40–42% Cr2O3.

Get Price

LIST OF ORES AND THEIR NAMES SULPHIDE ORE

2021-5-27  from chromite (FeCr2O4 Cr2O3 FeO). By Chemical separation Some of the ores are concentrated by means of chemical treatment. Leaching : It involues the treatment of the ore with a suitable reagent. as to make it soluble while impurity remain insoluble. The ore is recoverd from the solution by suitable chemical method. (i) Bayer's process

Get Price