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leaching process chromite ore

A clean and efficient leaching process for chromite ore ...

Jun 01, 2014 · Pressure leaching process of chromite ore in 50% KOH solution3.1.1. Effect of parameters. The application of KOH solution to process amphoteric mineral resources such as chromite ore, vanadium slag and titanium slag has been proved to be feasible and attractive (Liu et al., 2013, Liu et al., 2009, Zhang et al., 2005).

Leaching of Valuable Elements from the Waste Chromite Ore ...

chromite ore processing residue (COPR) is an inevitable solid emission in chromite salt production. It is an industrial waste produced during the extraction of Cr(VI) from a chromite ore using the high-temperature roasting process.11 In general, the COPR is alkaline (pH > 12),5 ,7 and because of the presence of partially water-soluble ...

Chemistry and leaching behavior of chromite ore processing ...

This study presents chemical, mineralogical, and leaching characterization of chromite ore processing residue (COPR) derived from the soda ash process, which is currently replacing the lime-based process in China, the world's largest chromite processor. Results indicated that, while soda ash COPR had 8,500 mg/kg Cr(VI), 90% of that was readily available in deionized water and thus the result of...

A clean and efficient leaching process for chromite ore ...

During the leaching process, other accompanying elements such as aluminum and silicon were extracted out from the chromite ore as well. However, their leaching products easily formed a

Chemistry and Leaching Behavior of Chromite Ore Processing ...

Nov 05, 2018 · This study presents chemical, mineralogical, and leaching characterization of chromite ore processing residue (COPR) derived from the soda ash process, which is currently replacing the lime-based process in China, the world's largest chromite processor.

Mineral processing: leaching process of chromium and ...

高达10%返现 · May 06, 2019 · The percent of reacted chromite ore can be maximized by increasing the roasting time of chromite ore with Na 2 CO 3 and also by raising the annealing temperature up to 1400 °C . Antony et al. have reported that, maximum percent formation and leaching of sodium chromate generally did not exceed 80–82%.

Leaching of hexavalent chromium from young chromite ore ...

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

Pressure oxidative leaching of Indian chromite ore in ...

Feb 01, 2014 · A novel process for leaching chromite ore has been proposed. Compared to the traditional alkaline roasting process, the new hydrometallurgical process lowers effectively the reaction temperature and enhances the leaching efficiency through pressure oxidative leaching with pure oxygen (O 2) in concentrated sodium hydroxide (NaOH) aqueous solution.The chromium (Cr) leaching

Treatability of chromite ore processing waste by leaching ...

Jun 01, 2001 · In this study, leaching characteristics of total Cr and Cr(VI) were investigated using laboratory column studies. The data obtained from the experimental studies were analysed to assess the treatability of chromite ore processing waste (COPW) by leaching and to identify the leaching strategies that enhance mass removal rates of chromium species.

The Leaching Characteristics of Chromite Ore Processing ...

Aug 11, 2016 · The Leaching Characteristics of Chromite Ore Processing Residue from China ... (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, ...

A clean and efficient leaching process for chromite ore ...

During the leaching process, other accompanying elements such as aluminum and silicon were extracted out from the chromite ore as well. However, their leaching products easily formed a

Leaching Process For Chromite

leaching process for chromite. A clean and efficient leaching process for chromite ore. In order to improve the chromate salts cleaner production technology, a pressure leaching process for ...

Chromium remediation or release? Effect of iron(II ...

Jul 15, 2003 · Effect of iron(II) sulfate addition on chromium(VI) leaching from columns of chromite ore processing residue. Geelhoed JS(1), Meeussen JC, Roe MJ, Hillier S, Thomas RP, Farmer JG, Paterson E. Author information: (1)The Macaulay Institute, Craigiebuckler, Aberdeen, AB 8QH, UK. [email protected]

(Bio)leaching Behavior of Chromite Tailings

The leaching of Cr for chromite tailings can be explained by two main processes. The first main process for Cr leaching is associated with the presence of phosphate anions in solution, which can exchange with chromate and bi-chromate anions, promoting the presence of Cr (VI) [ 46] in solution.

Preventing Chromium Leaching

Aug 19, 2018 · In this case, high chromium leachability is desired and is aided by the addition of lime to a mixture of chromite ore and Na2CO3. The CaO-Na2CO3 ore mixture is roasted at 1,100° to 1,150° C in an oxidizing air atmosphere, followed by water leaching of the roasted material to extract the chromium as Na2CrO4 in solution.

The production process of chromite sand | HAIXU - Chromite ...

Apr 24, 2020 · The process of chromite ore mining can be divided into 2 areas: 1. Feed preparation ... can be employed to remove unwanted fines from your chromite ore prior to material being stacked before the heap leaching process. Logwashers. Our RotoMax logwasher is suitable when processing chromite ore with clay contamination. The scrubbing process of the ...

Valorization of stainless steel slag by selective chromium ...

Mar 20, 2016 · A hydrometallurgical method, based on caustic soda leaching has been applied to Cr recovery from chromite ore as well as chromium oxides (Habashi, 1997, Gupta and Mukherjee, 1990). Chromium oxides present in slags readily dissolve with NaOH/KOH under oxidative pressure (1–3.2 Mpa) at 210–300 °C ( Zhang et al., 2014 , Xu et al., 2005 , Xu ...

Chromium - Wikipedia

The chromite ore is heated with a mixture of calcium carbonate and sodium carbonate in the presence of air. The chromium is oxidized to the hexavalent form, while the iron forms the stable Fe 2 O 3 . The subsequent leaching at higher elevated temperatures dissolves the

EP1697549B1 - A process for extraction of nickel from low ...

The present invention is a process for the extraction of nickel from low-grade chromite ore containing 0.6 to 0.9 % nickel, said process comprises of crushing, drying and grinding of low grade Chromite Ore to obtain +100 to -400 mesh B.S.S. with 85% -200 mesh B.S.S., subjecting the crushed ore to reduction-roasting with or without pre-mixing of oil, leaching the reduced material in an ammonia ...

roasting and leaching processess for chromium

Chromite / Chrome Ore - EK-Company & Co. KG. Chromite is the most important ore of chromium from which it derives its name. ... to be separated from the chromium in a two step roasting and leaching process. Read more

Chomite ore processing plants, CDE Global

Chromite. Chromite ore is predominantly used in the production of ferrochrome – an alloy of chrome and iron containing between 50% and 70% chromium. The production of steel is the largest consumer of ferrochrome, especially stainless steel production which contains between 10% and 20% ferrochrome content. The process of chromite ore mining ...

Chromium Remediation or Release? Effect of Iron(II ...

Jun 18, 2003 · Chemical and mineralogical characterization of chromite ore processing residue from two recent Indian disposal sites. Chemosphere 2016, 155, 188-195. DOI: 10.1016/j.chemosphere.2016.04.009. Yaguang Du, Maria Chrysochoou. Chemistry and Leaching Behavior of Chromite Ore Processing Residue from the Soda Ash Process.

Roasting and Leaching Behavior of Nickel Laterite Ore ...

Mar 29, 2021 · The success of the sulfation-roasting-leaching process depends on iron behavior. Due to its higher amount, it is sulfated before nickel. However, the stability of iron sulfates is lower than the nickel sulfate and during the decomposition of iron sulfate, the sulfur trioxide (SO 3) is liberated and reacts with nickel to form nickel sulfate.This mechanism can reduce considerably the acid ...

Speciation and Recovery of Chromium From Chromite Ore ...

Chromium contained in contaminated soils and solid wastes can be categorized as exchangeable, oxidizable, carbonate-bound, reducible and residual. The results from this study indicate a need for efficient leaching methodologies in chromite ore processing plants to decrease the non-detrital fractions of chromium in the residue.

Leaching of Valuable Elements from the Waste Chromite Ore ...

The efficacious treatment and resource utilization of the chromite ore processing residue (COPR) is important for chromate salt production. In this study, the leaching of valuable elements from the waste COPR was investigated. X-ray diffraction (XRD) analysis showed that the COPR mainly contained periclase (MgCr2O4), magnesiochromite ((Fe, Mg) (Cr, Fe)2O4), Fe (Cr, Al)2O4, and MgFeAlO4.

Leaching of chromite ore in concentrated KOH by catalytic ...

Apr 04, 2017 · The impacts of temperature, KOH-to-chromite ore mass ratio, CuO-to-chromite ore mass ratio, and gas flow rate on the chromium leaching rate were investigated. The results indicated that CuO played an important role in improving the chromium leaching rate.

Chromium remediation or release? Effect of iron(II ...

Jul 15, 2003 · Effect of iron(II) sulfate addition on chromium(VI) leaching from columns of chromite ore processing residue. Geelhoed JS(1), Meeussen JC, Roe MJ, Hillier S, Thomas RP, Farmer JG, Paterson E. Author information: (1)The Macaulay Institute, Craigiebuckler, Aberdeen, AB 8QH, UK. [email protected]

roasting and leaching processess for chromium

Chromite / Chrome Ore - EK-Company & Co. KG. Chromite is the most important ore of chromium from which it derives its name. ... to be separated from the chromium in a two step roasting and leaching process. Read more

Gold Metallurgy & Leaching in Cyanicides

Jul 14, 2016 · Optimize Gold Leaching & Recovery with Chromium Minerals. Lead Chromite (PbCrO4)5. Cyanidation as applied to ordinary gold and silver ores is a relatively simple process. When cyanicides {cyanide-consuming elements) are encountered in small amounts in the treatment of such ores, the various schemes already discussed, such as use of a lead salt ...

Extraction of Chromium from Chromite Ore

Jul 20, 2017 · The average grade of the metallurgical chromite ore was 43.4 pct Cr2O3, with 52 pct of the ore having a chromium-to-iron ratio of 3:1 or over, 17.6 pct having a ratio between 2:1 and 3:1, and 30.4 pct having a ratio less than 2:1. Chemical-grade chromite ore generally ranged from 40 to 46 pct Cr2O3 with a chromium-to-iron ratio of 1.5:1 to 2:1.

Valorization of stainless steel slag by selective chromium ...

Mar 20, 2016 · A hydrometallurgical method, based on caustic soda leaching has been applied to Cr recovery from chromite ore as well as chromium oxides (Habashi, 1997, Gupta and Mukherjee, 1990). Chromium oxides present in slags readily dissolve with NaOH/KOH under oxidative pressure (1–3.2 Mpa) at 210–300 °C ( Zhang et al., 2014 , Xu et al., 2005 , Xu ...

Leaching Process - Chemistry of Extracting Substances via ...

Leaching Process describes the release of organic and inorganic contaminants or radionuclides from a solid phase into a water phase, when influenced by processes such as desorption, complexation, and mineral dissolution. The Leaching Process is a universal process – Water will leach the components of any material it comes in contact with ...

Chromium - Wikipedia

The chromite ore is heated with a mixture of calcium carbonate and sodium carbonate in the presence of air. The chromium is oxidized to the hexavalent form, while the iron forms the stable Fe 2 O 3 . The subsequent leaching at higher elevated temperatures dissolves the

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

Apr 26, 2011 · 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 ...

Leaching (metallurgy) - Wikipedia

Leaching is a process widely used in extractive metallurgy where ore is treated with chemicals to convert the valuable metals within into soluble salts while the impurity remains insoluble. These can then be washed out and processed to give the pure metal; the materials left over are commonly known as tailings.Compared to pyrometallurgy leaching is easier to perform, requires less energy and ...

Remediation of chromite ore processing residue using ...

Sep 18, 2014 · Disposal of Chromite Ore Processing Residue (COPR) is a major concern from an environmental point of view because it consists mainly of Cr(VI) in addition to Cr(III). Cr(VI) is more soluble and mobile when compared to Cr(III). The study primarily concentrated on treatment of COPR using solidification and stabilization (S/S) process.

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

IntroductionOver 400 chromium-contaminated sites related to the chromite ore processing residue (COPR) have been identified in Hudson County and other areas in northern New Jersey, USA (MEMT, 1990). At these contaminated sites, chromium is continually leached from soils enriched in COPR even after decades of weathering.