(PDF) Chromite. Processing and Applications
Chromite is an oxide of iron and chromium with the chemical composition FeO.Cr2O3 and belonging to the spinel group. Theoretically it contains 46.5% Cr and 25.8% Fe and their oxides.
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Chromite is an oxide of iron and chromium with the chemical composition FeO.Cr2O3 and belonging to the spinel group. Theoretically it contains 46.5% Cr and 25.8% Fe and their oxides.
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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 …
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A new metallurgical process for extracting chromium from chromite ore is proposed to overcome the severe chromium (VI) pollution in chromate production industry. When the 60 wt.% KOH solution was used to decompose chromite ore, the chromium and iron ions in chromite ore were oxidized into soluble K 2 CrO 4 crystal …
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A Cr6+-FREE EXTRACTION OF CHROMIUM OXIDE FROM CHROMITE ORES USING CARBOTHERMIC REDUCTION IN THE PRESENCE OF ALKALI L. Escudero-Castejon, S. Sanchez-Segado, S. Parirenyatwa, Y. Hara, A. Jha The Institute for Materials Research, School of Chemical and Process Engineering,
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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 …
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Research highlights. High tailing losses from the existing chromite plants (9–20% Cr 2 O 3 ). Accumulation of huge amount of low and sub-grade fines (10–30% …
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Extraction. Chromite ((ce{FeCr2O4})) is the most commercially useful ore, and is extensively used for extraction of chromium. Chromium is …
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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 …
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The chemical composition of the chromite tailings sample is shown in Table 1. Table 1 shows that the sample had a chromite content of 20.03% with silica as the major gangue measured at 33.50%. The iron oxide content assayed at 17.94%. The chromite content corroborates the research that was conducted by [4] which indicated that there is sufficient
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Ferroalloys: Production and use in Steel-making. Y.E. Lee, in Encyclopedia of Materials: Science and Technology, 2001 (b) Ferrochrome–silicon Ferrochrome–silicon is another chromium ferroalloy directly produced from chromite ores by carbothermic reduction in submerged arc furnace. The chromium content ranges from 34 to 42%, that of silicon …
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Chromite is an oxide mineral composed of chromium, iron, and oxygen (FeCr 2 O 4 ). Chromite is the only ore mineral of chromium (Edwards, 2012). Further, in Balochistan, Pakistan, it occurs in in a rock series called the Muslim Bagh Ophiolite (Ahmad and Abbas, 1979). The major application of chromite is in production of stainless steel.
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A new leaching process for preparing chromium oxide from chromite was studied for this paper, using Cr (VI) extracted from the remediation treatment of chromite ore processing residue (COPR) as an ...
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Sukinda overburden is dumped with chromite ore tailing which contains about 17% Cr2O3. The other constituent with overburden is iron, silica and alumina. Because of its complex nature and large amount of gangue material it is not suitable for the extraction of valuable chromium by conventional route. The author of the present …
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An advanced sulfuric acid leaching process of chromite was proposed. •. All residual chromium was recovered and no hazardous wastes were discharged. The sulfuric acid leaching process is widely considered to be a cleaner technology to prepare chromium salt from natural chromite as no Cr (VI)-bearing wastes are generated or …
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Most recently, Chen has investigated the extraction of chromium from chromite ore in 50 wt% KOH solution, and reported that under the condition of oxygen pressure 1.0 MPa and leaching temperature 220 °C, chromium extraction rate reached up to 98.0% (Chen et al., 2013). These outcomes achieved by oxidative leaching suggest …
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Chromium is not added directly to the steel but in the form of ferrochrome, as the latter has a lower melting point. Many minerals contain chromium, but chromite is the only mineral from which chromium is extracted . The global ferrochrome market was valued at USD 16.10 billion in 2022 and is projected to grow to USD 24.03 billion by 2030.
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Oxidative alkali roasting of chromite is the state-of-the-art process for manufacturing chromium-containing chemicals, which involves dealing with serious environmental problems arising from handling Cr 6+-containing wastes generated in this process.In this article a new method for the extraction of Cr 2 O 3 from chromite ores is …
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Non-traditional metallurgical technology of comprehensive processing of Sevan chromite (with a 43–46% Cr 2 O 3 content) is developed allowing chromium …
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Chromite deposits are mined by both underground and surface techniques. Much of the ore is rich enough to be used directly: for … See more
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Regarding the chromium extraction from chromite concentrates, it can be observed that alkaline roasting provides the formation of a soluble intermediate salt containing the chemical element of interest which can be easily recovered.[12,13] It can be also affirmed that this is a possible chemical route to extract chromium from …
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DOI: 10.1016/j.jhazmat.2022.129754 Corpus ID: 251507844; Sufficient extraction of Cr from chromium ore processing residue (COPR) by selective Mg removal. @article{Zhang2022SufficientEO, title={Sufficient extraction of Cr from chromium ore processing residue (COPR) by selective Mg removal.}, author={Jing Zhang and Wenyu …
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The material is a hazardous waste derived from the extraction of chromate (CrO 4 2−) from 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).
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Contribute to sbmcrushers/sbmchina development by creating an account on GitHub.
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Conclusions. A new approach using sulfuric acid leaching for chromium oxide preparation from chromite was studied in this paper, in which recovered Cr 2 O 7 2 − -bearing leachate obtained from a COPR remediation process was used as an oxidant. An Eh-pH diagram of Cr–Fe–H 2 O at 160 °C was produced and experiments using …
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Various factors which influence the extent of extraction of chromium from COPR have now been reported. An extraction using sodium peroxide enables leaching of more than 95% …
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zenith-crusher. Extracting chromium from chromite involves several steps. Here's a general overview of the process: 1.Chromite Ore Preparation: The chromite ore, which is a combination of chromium ...
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1798, chromite is still considered as an economic source for chromium extraction. Theoretically, it is mainly composed of around 32.0% FeO and 68.0% Cr 2 O 3 and, also contains a number of ...
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Chromium mining involves extracting chromium from underground mines. Chromium is a naturally-occurring element found in rocks, animals, plants, soil, and in volcanic dust …
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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 …
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Two kinds of chromite with various Fe(II) contents were employed to verify the proposed speculation on the role of Fe(II) in the leaching process of chromite. Moreover, the subsequent extraction of chromium from the leachate was studied, and a new process for chromium oxide production from chromite is put forward in this paper. 2.
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Research about extraction of iron from chemical‐grade South African chromite by carbothermic reduction and hydrochloric acid leaching was conducted in this study. It was found that temperature had a remarkable effect on the extraction yield of iron and that the optimum experimental temperature was 1100 °C, which coincides with the …
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Chromite, FeCr 2 O 4, is the most commercially useful ore, and is extensively used for extraction of chromium. Chromium is produced in two forms: (Chemistry of the Elements, Greeenwood and Earnshaw, Chapter 23). (a) Ferrochrome by the reduction of chromite with coke in an electric arc furnace. A low-carbon ferrochrome …
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A new leaching process for preparing chromium oxide from chromite was studied for this paper, using Cr(VI) extracted from the remediation treatment of chromite ore processing residue (COPR) as an ...
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shifted to also recover chromite from the fine ( -75 µm) fractions. This paper describes the results of a series of fine chromite bench flotation tests that have been carried. out at acidic and ...
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Chromite mining activities are indispensable for production of goods and services. Sukinda is a major mining site of Odisha, India, polluted by chromium, which is highly toxic in its hexavalent form. The Sukinda valley is a rich source of chromites, amounting to almost 95% of Cr available in India, and is the fourth most polluted site …
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Chromite varies widely in composition according to the chemical formula (Mg, Fe +2) (Cr, Al, Fe +3) 2 O 4. Chromium occurs as chromium spinel, a complex mineral containing magnesium, iron, aluminium and chromium in varying proportions depending upon the deposit. Iron is replaced by magnesium and similarly chromium by ferric iron …
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Chromite is an oxide mineral composed of chromium, iron, and oxygen (FeCr 2 O 4 ). It is dark gray to black in color with a metallic to submetallic luster and a high specific gravity. It occurs in basic and ultrabasic igneous rocks and in the metamorphic and sedimentary rocks that are produced when chromite-bearing rocks are altered by heat or ...
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Increasing demand of chromium in steelmaking industries and the gradual depletion of high-grade chromite ores have led to the extraction of chromium from low-grade ores …
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