Run-of-mine (ROM) chromite (defined as ore recovered during mining and before further processing) is typically beneficiated before smelting, using a relatively wide variety of processes. Murthy et al. (2011) stated that the most generally used processes are primary and secondary crushing, screening, milling, dense media separation, and gravity ...
DetailsChromite ore processing tailings and low-grade manganese ores are typically considered waste due to their limited or negligible utility, leading to environmental and storage concerns. Researchers globally have explored various methods to utilize or upgrade these wastes, particularly because dumping chromite ore has been linked to …
Detailschromium 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 corrosion, resulting in its application as an …
DetailsChromite Ore Processing Residue (COPR) is the byproduct of chromate production process, which contains a large amounts of Cr(VI). The present work developed a new technique to treat COPR, and the process involved mixing the COPR with rice straw followed by pyrolysis. It was found that the gaseous organic fraction generated during …
DetailsThe main component of the chromium ore is chromite FeCr 2 O 4. The ores extensively dispersed in natural deposits and generally contaminated with Mg, Si, Al, and O. The chromium metal commercially separated by oxidizing chromite ore to Cr 2 O 3, then the metal is attained by heating the Cr 2 O 3 in the presence of Al or Si [5,6].
DetailsChromium ore is typically found in the Earth's crust in the form of chromite, which is a dark, black to brownish-black mineral.Chromite is composed of chromium, iron, and oxygen, with the …
DetailsThe current strategy reports the recovery of precious group metals (PGMs) from Na2CO3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under atmospheric O2. The influence of roasting temperature (960–1200 °C) and leaching agents (H2O, HCl, H2SO4) and their concentrations on the recovery of PGMs was studied. Chromite roast …
DetailsSedimentation studies of chromite ore process tailings using anionic (a, b), cationic (c) and nonionic polyacrylamide (d) flocculants. Download : Download high-res image (254KB) Download : Download full-size image; Fig. 6. The effect of polymer type and dosages on the settling rate of different chromite ore process tailings.
DetailsThe important beneficiation process in the chrome processing plant mainly include comminution and concentration. 1. Comminution. Chrome lump ore, or chrome …
DetailsChromite mining in Turkey started in 1850; since then, Turkey has had an important role in the world chromite market. Turkey produces chromite ore and ferrochrome. It is estimated that Turkey has produced about 45 metric tons of chrome ore. Chromite production is mainly export-oriented. Turkey has one chrome and two ferrochrome chemical plants.
DetailsSoda-based chromite ore processing residue (COPR) is a hazardous waste produced from chromium salt plants. In this study, detoxified water-washed chromite ore processing residue (DW-COPR) was investigated as a catalyst to activate peroxymonosulfate (PMS) to degrade tetracycline (TC) in the presence of visible light.
Details1. Introduction. Chromite ore processing residues (COPR) are hazardous industrial wastes which have been disposed in surface soils at many commercial and industrial sites in the USA, UK, China, Japan, India and in many other countries (Dhal et al., 2013).One of the biggest threats of COPR to the environment is the release of …
DetailsChromite 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 …
Details1. Introduction. Chromite ore processing residue (COPR) is a Cr(VI)-containing hazardous waste generated during the production of chromate. Residual chromium in COPR from lime-based roasting can be as high as 50,000 mg/kg, up to 50% of which is hexavalent chromium [1], [2], [3], [4].The lime-based roasting process has …
DetailsThe pyrolysis treatment with biomass is a promising technology for the remediation of chromite-ore-processing residue (COPR). However, the mechanism of this process is …
DetailsThe 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 …
DetailsRemediation process and utilization treatment of chromite ore processing residue (COPR) is an environmental issue which is not solved completely. Based on the characteristics of industrial lime-free COPR, a two-step treatment procedure including water leaching and biomass pyrolysis was proposed in this study. The results indicated that …
DetailsThe process for chromate salt production technology is greatly simplified. •. The high energy consumption required for alkali recycling can be avoided. •. The leaching …
DetailsThis article reviews the major process flow sheets in practice for the recovery of chromite values from various types of ores and critical issues related to chromite ore …
DetailsHexavalent chromium contamination is a global environmental issue and usually reoccurs in alkaline reduced chromite ore processing residues (rCOPR). The oxidation of Cr(III) solids in rCOPR is one possible cause but as yet little studied. Herein, we investigated the oxidation of Cr(OH)3, a typical species of Cr(III) in rCOPR, at alkaline …
DetailsChromite 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 …
DetailsThe Problem with Chromite Processing Experience indicates that chrome ores are concentrated to best advantage by gravity methods. Since recoveries are generally very poor in the fine sizes, the gravity flowsheet must be designed to remove the chrome as soon as liberated by crushing and grinding. For example, if the chrome is not entirely …
DetailsSupply of world chromite (chrome ore) has come under severe pressure over the past year driven by strong demand for ferrochrome used in ferroalloy production for making stainless steel. ... Extraction of Cr(VI) from chromite ore processing residue via hydrothermal-assisted phase transformation. Chinese Chemical Letters, Volume 31, …
DetailsDOI: 10.1016/j.chemosphere.2009.08.023 Corpus ID: 34009680; Treatment of chromite ore processing residue by pyrolysis with rice straw. @article{Zhang2009TreatmentOC, title={Treatment of chromite ore processing residue by pyrolysis with rice straw.}, author={Dalei Zhang and Shengbing He and Luwei Dai …
DetailsChromite ore processing residue (COPR), which is created during the chromite preparation process of chromite compounds, is considered hazardous waste because it contains chromium trivalent and chromium hexavalent. Recently, the harmless disposal of COPR has received a lot of research interest. COPR is a type of resource …
DetailsAbstract. The current strategy reports the recovery of precious group metals (PGMs) from Na 2 CO 3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under atmospheric …
DetailsResidual unreacted Cr(VI) incorporated in ferrous-sulfate-reduced chromite ore processing residue (rCOPR) can be slowly released during deposition, posing a significant threat to the environment.Recent studies indicate that such Cr(VI) mainly exists within the nano-sized ion channels of ettringite, forming Cr(VI)–ettringite.Therefore, efficient …
Details1. Introduction. 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 …
Details1. Introduction. In 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 …
DetailsChromite 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.
DetailsA new green metallurgical process for chromite ore has been proposed and developed to solve the serious environmental problem in the traditional production process of chromate. In the new process, the oxidation of chromite ore is carried out in sub-molten potassium hydroxide at 300 °C. Compared with the traditional roasting …
Details1. Introduction. The soda ash roasting process produces Chromite Ore Processing Residue (COPR) containing 1130–8500 mg/kg carcinogenic hexavalent chromium (Cr(VI)) due to the industrial incomplete leaching (Du and Chrysochoou, 2018, Chrysochoou et al., 2009)pared with the lime-based roasting process, soda ash as …
DetailsChromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr [VI]). Although the high …
DetailsChromite tailings ore sample was obtained from a MG chromite processing plant in the Western Limb of the Bushveld Igneous Complex (BIC), South Africa. Characterisation studies were carried out to quantify the different mineral phases, their liberation and association with each other [7].
DetailsChromite 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 ...
DetailsThe 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 …
DetailsFigure 3—Conventional process ow sheet for chromite ore bene ciation. Figure 4—Bene ciation of Indian chromite ores.
DetailsExperimental and modeling studies were conducted to delineate the reaction progress of chromite ore processing residue (COPR) upon hydration and the roles of brownmillerite and calcium aluminum chromium oxide hydrates (CAC) in the scavenging of hexavalent chromium. A kinetic study was conducted by preparing slurry samples with …
Details1. Introduction. 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 …
DetailsPE series jaw crusher is usually used as primary crusher in quarry production lines, mineral ore crushing plants and powder making plants.
GET QUOTE