The existence of leachable Cr(Ⅵ) in chromite ore processing residue (COPR) makes it hazardous waste. Therefore, resourceful utilization of COPR is necessary to protect the ecosystem and living biota from hazardous effect of Cr(Ⅵ) caused by its leaching. In this study, detoxification and immobilization of COPR was carried out through ...
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In this work, a series of long-term treatment trials were conducted to evaluate the remediation performance of amorphous iron pyrite (FeS 2(am)) toward hexavalent chromium (Cr(VI)) in chromite ore processing residue (COPR).The effectiveness of FeS 2(am) was assessed using alkaline digestion, the synthetic precipitation leaching procedure (SPLP) and …
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Among more than fifty kinds of Chrome minerals found in nature, chromiteis the sole commercial source. The chromite ore is concentrated in South Africa, Zimbabwe, Kazakhstan, Russia, Finland, India. South Africa is the major chromite ore supplier. Chromite is weekly magnetic. Its …
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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 ...
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The processing of alluvial chrome ore and rock chrome ore includes a series of physical and chemical treatment steps to extract commercially valuable chromium from sand …
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This complete system is a 150 TPH alluvial chrome ore processing plant configured with a vibrating feeder, trommel screen, belt conveyor, slurry pump, and spiral chute. The raw ore information is as below: …
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Chromium Ore Processing Residue (COPR) Site Initiative Background and Site Location 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
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JXSC support customized chrome ore beneficiation process mainly including washing, crushing, grinding, gravity and magnetic separation equipment, with low cost and maximize recovery ore. Chrome has strong siderophilicity, and …
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Chromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr(VI)). Although the high temperature chromite process was banned in several countries, its legacy still exists at numerous contaminated sites. For instance, New Jersey alone has over 2 million tons of waste COPR. …
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Among various forms of Cr contamination, the chromite ore processing residue (COPR) possess a great environmental and health risk with persistent Cr(VI) release at appreciable concentrations [2], [3]. In addition to inhalation and drinking, incidental ingestion of Cr-containing dusts is a potential important exposure route for nearby residents.
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The Chromite Extraction Flowsheet Chromite Ore Crushing. The crushing section for this 250 ton per day chrome mill consists of a coarse ore grizzly, a coarse ore bin with pan feeder to a 1'8″ reduction crusher and a crusher discharge conveyor to a crushed ore bin. ... Chromite Process Summary.
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Chromite Ore Processing Residue was produced in large quantities in various countries and was deposited as backfill material in residential and commercial areas. There are two problems with COPR ...
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1. Introduction. Chromite ore processing residue (COPR) is a by-product in the production of chromium salt by the mainstream technology of the calcium-free roasting process (Liao et al., 2017a).The COPR is considered as a hazardous industrial solid waste because it contains 1%–2% hexavalent chromium (Cr(Ⅵ)) (Chrysochoou and Dermatas, 2007), which …
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Abstract 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 …
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Considering the tailing disposal problems of chromite gravity concentration plants, the research works of Amer and lbrahim (1996) on hydrometallurgical processing of low-grade chromite ore (Barramiya, Egypt), using mechanical alkaline treatment in an attritor followed by oxidative leaching in an autoclave reveals that single-stage leaching at ...
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A typical chromite processing flowsheet follows the crushing, screening, and milling of the ore; classification by wet-screening or desliming hydrocyclones; dense media separation (DMS cyclone for coarse processing) or spiral circuits and tabling . Chromite is paramagnetic and can be separated from the associated gangue by magnetic separation ...
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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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How to determine the chrome ore concentrating method and select the right chrome mining equipment is closely related to the physical and chemical properties of chromium ore. Because chromite is weakly magnetic, the technology of purifying chromium ore with high-intensity magnetic separation has been very mature with the development of high ...
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Manufacturing of chromium products yields 6 million tons of soda ash chromite ore processing residue (COPR) annually (Zhang et al., 2022).Due to incomplete leaching of the material generated during production of Na 2 CrO 4 salt, the soda ash COPR contains approximately 1130–8500 mg/kg carcinogenic hexavalent chromium (Cr(VI)) (Chen et al., …
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Chromite Ore Processing. Low-grade ore obtained from an open cut trench at a chromite deposit near Auburn, Calif., was treated in the laboratory using gravity-magnetic separation and flotation beneficiation techniques. Flotation using known methods, however, gave very poor results and will not be discussed further in this report. Tabling of the ...
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China annually generates millions of tonnes of chromite ore processing residue (COPR), firmly positioning it as a prominent global leader in the chromate industry, having processed approximately 40 % of the world's chromate compounds since 2009, as reported by the (Ministry of Industry and Information Technology, 2012).The country has accumulated a …
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Chromium processing, preparation of the ore for use in various products. Chromium (Cr) is a brilliant, hard, refractory metal that melts at 1,857 °C (3,375 °F) and boils at 2,672 °C (4,842 °F). In the pure state it is resistant to ordinary …
WhatsApp: +86 18221755073In the industrial production of chromium and chromate, a large amount of Chromium Ore Processing Residue (COPR) is produced (Antony et al., 2013).COPR contains a lot of soluble hexavalent chromium Cr(VI) with high fluidity, high oxidation state, and high toxicity, which seriously threatens human life and health (Suljevic et al., 2021; VonHandorf et al., 2021).
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Below, let's take you to learn about each chromite ore processing process. 1. Gravity Separation. From the point of production practice, the gravity separation is still the …
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The production of chromate from the roasted chromite produces millions tons of Chromite Ore Processing Residue (COPR) annually [1], [14]. Due to the industrial incomplete roasting and leaching, about 6 wt% of Cr remain within COPR particles including 1130 − 8500 mg/kg of hazardous Cr(VI) [7]. Unlike less toxic and less mobile Cr(III), Cr(VI ...
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Chromite Ore Processing Residue (COPR) is a solid waste generated during the high temperature (∼1200 °C) roasting process that is used to extract chromium from chromite ore (Antony et al., 2006). Lime-based roasting has been the prevalent method to complex other metals in ore (Fe, Mg, Al) and isolate Cr.
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Figure 3:Liberation pattern of chromite ore 3.2 Processing of chromite using MGS Processing of the chromite sample was carried out with top sizes, viz. -250µm, -150µm and -75µm. The effect of other process parameters on MGS were studied and performance was investigated with respect to grade and recovery of the Cr2O3%. Results obtained from ...
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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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Chromite ore processing residue (COPR) is a typical hazardous waste produced during the manufacture of chromium salt. It is estimated that the total amount of COPR is more than three million tons in China, and the annual increase is approximately sixty thousand tons (Sun et al., 2014).
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Figure 3—Conventional process ow sheet for chromite ore bene ciation. Figure 4—Bene ciation of Indian chromite ores.
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نشانی: شماره 1688، جاده شرقی گاوک، منطقه جدید پودونگ، شانگهای، چین.
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