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Remediation of chromium-slag leakage with electricity

Aug 29, 2014UK investigators estimated that approximately 2.5 million tons of chromite ore processing residue were found on several in the leachate. However, the final released amounts of Cr(VI) were

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Cited by: 15

Extraction of Cr(VI) from chromite ore processing residue

Jul 01, 2020The effective extracting Cr(VI) from chromite ore processing residue (COPR) is the key to achieve COPR detoxification and recovery. We developed an effective method to extract Cr(VI) from COPR via controlling the phase transformation of Cr(VI)-containing minerals. Characteristic analysis showed that Cr(VI) was mainly incorporated in the hydrocalumite

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Author: Xiaofeng Mo, Jin Zhou, Le Lin, Zuqi Zhong, Shaohua Yang, Xueming Liu, Zhenqing Shi, Dongye Zhao, Zha...

Leaching of hexavalent chromium from young chromite ore

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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Author: Katrin Matern, Harald Weigand, Ruben Kretzschmar, Tim Mansfeldt

CHROMITE ORE PROCESSING RESIDUE LEACHATE

CHROMITE ORE PROCESSING RESIDUE LEACHATE DETOXIFICATION USING OPAQUE BEER BREWERY WASTE WATER A thesis submitted by MABLE MUTANDWA (B1129533) In partial fulfilment of the requirements of the degree of MASTER OF SCIENCE IN ANALYTICAL CHEMISTRY under the esteemed guidance of Dr C. MAHAMADIDr J. TSHUMA APRIL 2014

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Leaching mechanisms of Cr(VI) from chromite ore processing

Oct 23, 2008Leaching mechanisms of Cr(VI) from chromite ore processing residue. Wazne M(1), Jagupilla SC, Moon DH, Christodoulatos C, Koutsospyros A. Author information: (1)Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA. [email protected]

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Cited by: 39

(PDF) Leaching Mechanisms of Cr(VI) from Chromite Ore

Chromite ore processing residue (COPR) is a hazardous waste. Nevertheless, deposition of COPR in uncontrolled surface landfills is still common practice in some countries.

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Biogenic nano-magnetite and nano-zero valent iron

@article{osti_1343921, title = {Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue}, author = {Watts, Mathew P. and Coker, Victoria S. and Parry, Stephen A. and Pattrick, Richard A. D. and Thomas, Russell A. P. and Kalin, Robert and Lloyd, Jonathan R.}, abstractNote = {Highly reactive nano-scale

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Recovery of chromium and magnesium from spent magnesia

Nov 15, 2019Magnesia-chrome refractories are mainly made of magnesia and chromite. China's chromite resources are poor, mainly relying on imports, and the dependence on foreign countries is increasing year by year . It is predicted that the supply and demand gap of China's chromite ore will reach 4.3 million tons by 2020 .

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Leaching of hexavalent chromium from young chromite ore

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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Hazardous Waste Disposal in Stromatolitic-Limestone

Background. Hexavalent chromium-containing waste from chromite ore processing is a major environmental health hazard due to its high toxicity. There have been instances of

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Biogenic nano-magnetite and nano-zero valent iron

@article{osti_1343921, title = {Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue}, author = {Watts, Mathew P. and Coker, Victoria S. and Parry, Stephen A. and Pattrick, Richard A. D. and Thomas, Russell A. P. and Kalin, Robert and Lloyd, Jonathan R.}, abstractNote = {Highly reactive nano-scale

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(PDF) Sulfuric acid leaching of Turkish chromite concentrate

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly

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(Bio)leaching Behavior of Chromite Tailings

The results show three fold less Cr in the leachate of the concentrated ore sample (47 mg/kg) compared with the leachate of the fresh tailing sample (147 mg/kg), suggesting that chromite is not the main source of Cr release from the tailings.

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CORE

Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue By Mathew P. Watts, Victoria S. Coker, Stephen A. Parry, Richard A D Pattrick, Russell A P Thomas, Robert Kalin and Jonathan R. Lloyd

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Chromium Remediation or Release? Effect of Iron(II

Jun 18, 2003Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12. Ferrous sulfate, which is used for remediation of Cr(VI) contamination in wastewater and soils via reduction to Cr(III) and subsequent precipitation of iron(III)/chromium(III) hydroxide,

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Chromate Reduction in Highly Alkaline Groundwater by

It is not currently known if the widely used reaction of zerovalent iron (ZVI) and Cr(VI) can be used in a permeable reactive barrier (PRB) to immobilize Cr leaching from hyperalkaline chromite ore processing residue (COPR). This study compares Cr(VI) removal from COPR leachate and chromate solution by ZVI at high pH. Cr(VI) removal occurs more rapidly from the chromate

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Chromite Wikipedia

Chromite is found as orthocumulate lenses of chromitite in peridotite from the Earth's mantle.It also occurs in layered ultramafic intrusive rocks. In addition, it is found in metamorphic rocks such as some serpentinites. Ore deposits of chromite form as early magmatic differentiates. It is commonly associated with olivine, magnetite, serpentine, and corundum.

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Treatment of Alkaline Cr(VI)-Contaminated Leachate with an

Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline

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Biogenic nano-magnetite and nano-zero valent iron

Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue Mathew P. Watts,a, 1 Victoria S. Coker,a Stephen A. Parry,b Richard A.D. Pattrick,a Russell A.P. Thomas,c Robert Kalin,d and Jonathan R. Lloyd a, ⁎

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New study explores leaching of hexavalent chromium from

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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MODELING CHROMIUM LEACHING FROM CHROMITE ORE

MODELLING CHROMUM LEACHING FROM CHROMITE ORE PROCESSING WASTE YALÇIN, Sezgin M.S., Department of Environmental Engineering Supervisor: Prof. Dr. Kahraman Ünlü September 2003, 92 pages Chromium has been widely used in many industrial applications. As a result of chromite

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Chromium Ore Processing Residue

Chromium Ore Processing Residue. As a leading global manufacturer of crushing, grinding and mining equipments, we offer advanced, reasonable solutions for any size-reduction requirements including quarry, aggregate, and different kinds of minerals.

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Chromate Reduction in Highly Alkaline Groundwater by

It is not currently known if the widely used reaction of zerovalent iron (ZVI) and Cr(VI) can be used in a permeable reactive barrier (PRB) to immobilize Cr leaching from hyperalkaline chromite ore processing residue (COPR). This study compares Cr(VI) removal from COPR leachate and chromate solution by ZVI at high pH. Cr(VI) removal occurs more rapidly from the chromate

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(PDF) Chromate reduction in Fe(II)-containing soil

The speciation and behaviour of chromium leached from highly alkaline chromite ore processing residue (COPR) within the soils beneath the waste is investigated. Water in contact with the COPR had a pH of 12.2 and contained 990 µmols L-1 Cr(VI). This

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CORE

Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue By Mathew P. Watts, Victoria S. Coker, Stephen A. Parry, Richard A D Pattrick, Russell A P Thomas, Robert Kalin and Jonathan R. Lloyd

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Chromate reduction in Fe(II)-containing soil affected by

Highly alkaline (pH 12.2) chromate contaminated leachate (990 molL−1) has been entering soils below a chromite ore processing residue disposal (COPR) site for over 100 years. The soil immediately beneath the waste has a pH of 11→12.5, contains 0.3→0.5% (w/w) chromium, and 45→75% of the microbially available iron is Fe(II).

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CORE

Highly alkaline (pH 12.2) chromate contaminated leachate (990 μmol L−1) has been entering soils below a chromite ore processing residue disposal (COPR) site for over 100 years. The soil immediately beneath the waste has a pH of 11 → 12.5, contains 0.3 → 0.5% (w/w) chromium, and 45 → 75% of the microbially available iron is Fe(II).

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New study explores leaching of hexavalent chromium from

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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Leaching mechanisms of Cr(VI) from chromite ore processing

Batch leaching tests, qualitative and quantitative x-ray powder diffraction (XRPD) analyses, and geochemical modeling were used to investigate the leaching mechanisms of Cr(VI) from chromite ore processing residue (COPR) samples obtained from an urban area in Hudson County, New Jersey. The pH of the leaching solutions was adjusted to cover a wide range between 1 and 12.5.

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MODELING CHROMIUM LEACHING FROM CHROMITE ORE

MODELLING CHROMUM LEACHING FROM CHROMITE ORE PROCESSING WASTE YALÇIN, Sezgin M.S., Department of Environmental Engineering Supervisor: Prof. Dr. Kahraman Ünlü September 2003, 92 pages Chromium has been widely used in many industrial applications. As a result of chromite

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Chromite (Cr2FeO4) FeCr2O4 PubChem

ANIMAL STUDIES: A single sc injection of chromite ore (equiv to 0.5 mg Cr) gave rise to sarcomas at site of injection in 3 out of 52 mice. A group of six female albino rabbits, six months of age, received 6 once weekly intravenous injections of 25 mg of chromite ore; treatment was repeated in 4/6 rabbits nine months later.

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Treatment of Alkaline Cr(VI)-Contaminated Leachate with an

Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline

get price

A preliminary study on leachability of chromium from a

In the present article, chromite ore processing residue (COPR) and soil samples were collected from a chromium contaminated site in Tamil Nadu State, India. Around 155.02 and 28.01 mg g −1 of Cr(VI) was present in COPR and soil samples, respectively. Leachability studies were carried out to assess the leachability of Cr(VI) and Cr(III) from

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Leaching Mechanisms of Cr(VI) from Chromite Ore Processing

Batch leaching tests, qualitative and quantitative x‐ray powder diffraction (XRPD) analyses, and geochemical modeling were used to investigate the leaching mechanisms of Cr(VI) from chromite ore processing residue (COPR) samples obtained

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Leaching Mechanism of Cr(VI) from Chromite Ore Processing

The leaching behavior of hexavalent chromium (Cr(VI)) and major metal elements relevant to Cr(VI) leaching from chromite ore processing residue (COPR) to HNO3 are investigated by batch leaching tests. According to the test results, aqueous Cr(VI) accounted for 70-80% of the content of total Cr. Cr(VI) concentration was controlled by the dissolution degree of Cr(VI)-bearing

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Cleaner Production of Chromium Oxide from Low Fe(II)-Chromite

Sulfuric acid-based leaching is a promising cleaner method to produce chromium salts, but its feasibility for treating low Fe(II)-chromite still remains to be proven. A Box–Behnken design (BBD)-based set of experiments for sulfuric acid leaching of low Fe(II)-chromite was utilized in this work for generating an experimental dataset for revealing the functional relationships

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