A new method for the treatment of chromite ore processing residues
Two key points for the treatment of chromium ore processing residue. Ind. Chromium Salts, 2 (2004), pp. 1-14 (in Chinese) View in Scopus Google Scholar [18] B.R. James, Method to reduce hexavalent chromium in soils, sediments, industrial wastes and other contaminated materials using ascorbic acid, US Patent 6,221,002 (2001).
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A new method for the treatment of chromite ore processing residues
Chromite ore processing residue (COPR), derived from the so-called high-lime processing of chromite ore, contains a significant fraction of a leachable Cr(VI) which is harmful to human being and other organisms. In recent years, the concern over environmental pollution from the waste residue containing Cr(VI) has become a major problem for the chromium chemical …
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Characterization of Chromite Ore Processing Residue
This paper summarizes the characteristics of chromite ore processing residue (COPR) in terms of their chemical compositions, phases, and recycling potential of iron and chromium through preliminary magnetic separation. COPR from nine hazardous waste ...
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Microstructural Analyses of Cr(VI) Speciation in Chromite Ore
The speciation and distribution of Cr(VI) in the solid phase was investigated for two types of chromite ore processing residue (COPR) found at two deposition sites in the United States: gray-black (GB) granular and hard brown (HB) cemented COPR. COPR chemistry and mineralogy were investigated using micro-X-ray absorption spectroscopy and micro-X-ray diffraction, …
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Chromium Ore Processing Residue
The reduction of chrome bearing ores in the production of industrial grade chromium compounds results in a waste rich in metals contamination. This byproduct is variously referred to as chromite ore processing residue, chrome ore processing residual or chrome tailings; for the purposes of …
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Collaborative resource utilization of hazardous chromium ore …
Much chromite ore processing residue (COPR), which is defined as hazardous solid waste due to virulent Cr (Ⅵ), is produced from chromium salt industry. C-bearing dust from …
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Chromium Remediation or Release? Effect of Iron (II) Sulfate …
Chromite 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.
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Stabilization of Chromium Ore Processing Residue (COPR
Cao and Zhang (2006) study the remediation of heavily contaminated groundwater and chromium ore processing residue (COPR) samples following the pathway of reduction and precipitation ...
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A detoxification and value-added process for chromium ore …
Chromite ore processing residue (COPR) is a byproduct produced in chromite processing at high temperature (1000–1200 °C). 2.5–3 tons of lime-based COPR were …
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Fresh and Aged Chromite Ore Processing Residues (COPR
Chromite ore processing residue (COPR) is a hazardous waste generated during the industrial extraction of chromium (Cr) from the feedstock ore (Chrysochoou & Dermatas, 2011; Freese et al., 2014; Matern, 2017).Due to inefficient conversion and extraction it usually retains 2–8 wt.-% of Cr, over 30% of which can be present in its hexavalent form Cr(VI) (Chrysochoou …
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Efficient reduction of Cr(VI) and recovery of Fe from chromite ore
Chromite ore processing residue (COPR) is a by-product generated after the leaching of sodium chromate by roasting chromite ore at 1200 °C. However, ... Reduction and immobilization of hexavalent chromium in chromite ore processing residue using amorphous FeS2. Sci. Total Environ., 658 (2019), pp. 315-323.
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Stabilization of chromium ore processing residue (COPR) with
Laboratory batch experiments were conducted on heavily contaminated groundwater and chromium ore processing residue (COPR) samples to determine the rate and extent of hexavalent chromium [Cr(VI)] reduction and immobilization by nanoscale iron particles. Laboratory synthesized nanoscale iron particles (<100 nm, specific surface area 35 m(2)/g ...
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Chromite Ore Processing Residue Management
Chromite ore processing residue (COPR) is a hazardous waste produced during the extraction of chromium from chromite ore. The management of COPR is crucial due to its environmental …
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(PDF) A Review of Chromite Ore Processing Residue …
Chromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr …
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Calcium polysulfide remediation of hexavalent chromium contamination
Past disposal of high-lime chromite ore processing residue (COPR) from a chemical works in S.E. Glasgow, UK, has led to continuing release of toxic and carcinogenic hexavalent chromium (Cr(VI)) to groundwaters which are highly contaminated with Cr(VI)O 4 2−.Traditional methods of remediating Cr(VI)-contaminated land, e.g. using ferrous sulfate and organic …
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Research progress on hazardous chromite ore processing …
Chromite ore processing residue (COPR), which is created during the chromite preparation process of chromite compounds, is considered hazardous waste because it …
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Ettringite-Induced Heave in Chromite Ore Processing Residue …
A pilot-scale treatment study was implemented at a deposition site of chromite ore processing residue (COPR) in New Jersey. Ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O) was employed to reduce hexavalent chromium in two dosages with three types of soil mixing equipment. XANES analyses of treated samples cured for 240 days indicated that all treatment combinations failed …
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Chrome steel from chromium ore processing residue
T1 - Chrome steel from chromium ore processing residue. AU - Kamolpornwijit, Wiwat. AU - Meegoda, Jay N. PY - 2011. Y1 - 2011. N2 - In Hudson County, New Jersey, there are more than two million tons of leftover chromite ore processing residues (COPR). Part of COPR was used as construction fill materials spreading the problem to a larger area.
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Reduction and immobilization of hexavalent chromium in chromite ore
DOI: 10.1016/j.scitotenv.2018.12.042 Corpus ID: 58661567; Reduction and immobilization of hexavalent chromium in chromite ore processing residue using amorphous FeS2. @article{Li2019ReductionAI, title={Reduction and immobilization of hexavalent chromium in chromite ore processing residue using amorphous FeS2.}, author={Yunyi Li and Jialiang Liang …
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(PDF) Chromite Ore Processing Residue: Review & Remediation
Chromium ore processing residue (COPR) dump site at M/s Tamilnadu Chromates and Chemicals Ltd (TCCL), Ranipet, Vellore Dt., Tamilnadu, India contains about 2.2 lakh tonnes of untreated chromium ore processing residue. The ground water in and around the site is highly contaminated with hexavalent chromium. The runoff and leachate from the TCCL ...
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Long-term treatment issues with chromite ore processing residue …
A pugmill treatability study was conducted to remediate chromite ore processing residue (COPR) using ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O) as a reductant. Two …
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Stabilization of chromium ore processing residue (COPR) with …
Chromium has been classified as a potential carcinogen [8], and has high and acute toxicity to humans, animals, plants, and microorganisms. Consequently, chromium contaminant in groundwater, chromium ore processing residue (COPR), and sediment represents a significant environmental and public health concern [9].
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The disposition of chromite ore processing residue (COPR) incorporating
Chromite ore processing residue (COPR) produced during the manufacture of chromates and dichromates consists of high temperature oxides, brownmillerite (Ca 2 FeAlO 5) and periclase (MgO), possibly excess hydrated lime, and various impurities such as hydrogarnet, brucite and so on, including chromium in both its trivalent and hexavalent form (Deakin et al., …
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An overview of the properties and treatment of chromite ore processing
Chromite Ore Processing Residue was produced in large quantities in various countries and was deposited as backfill material in residential and commercial areas.
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MINERALOGICAL PROPERTIES OF CHROMIUM ORE …
Chromium ore processing residue (COPR) has been disposed at hundreds of sites in the US mid-Atlantic Region, including major transportation corridors, harbors, and facilities.
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Extraction of Cr(VI) from chromite ore processing residue via
The 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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Modifications to EPA Method 3060A to Improve Extraction of …
It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil. Aluminum and …
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Conversion of Chromium Ore Processing Residue to Chrome Steel
Assessment of Brownmillerite and Periclase Hydration in Chromite Ore Processing Residue at Elevated Temperature. Previous. NEXT CHAPTER. Current Knowledge on Heaving Mechanisms of Chromite Ore Processing Residue ... The primary objective of this manuscript is to demonstrate an efficient and optimum way to recover chromium and iron from COPR in ...
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Specific Gravity of Expansive Chromium Ore Processing Residue …
Abstract. Specific gravity tests were performed on chromium ore processing residue (COPR), an expansive industrial byproduct of the historical processing of chromite ore, to determine if the complexity and heterogeneity of the particle microstructure may cause erroneous specific gravity results using ASTM D854-06 Method B as the baseline procedure. In complex, …
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Sufficient extraction of Cr from chromium ore processing residue …
Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr 2 O 3 cannot be extracted after chromite sodium roasting and remains in COPR, wasting valuable Cr resources. In this study, Mg was selectively removed by using (NH 4) 2 SO 4 roasting in combination with H 2 SO 4 leaching. The results …
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