In this paper, low-grade limonitic nickel laterite and chromite were synergistically utilized via the hybrid sintering process (i.e., pellet-sintering process) for high-quality Ni–Cr sinter preparation and great carbon emission reduction. Under the optimum process conditions, Ni–Cr sinter indices were substantially improved in the pellet-sintering process. Tumble index and …
Chromite ore processing residue occurs at over 130 sites in Hudson County, New Jersey. Many of these sites are in urban residential areas. This waste is a result of 70 years of chromate and ...
and economic indices of production chromite pellets and ferrochrome. Article info Received: 20 December 2014 Received and revised form: 23 March 2015 Accepted: 10 May 2015 Keywords: chromite ore ...
Chromite ore processing residue (COPR) is a kind of hazardous industrial solid waste produced in the chromium salt industry that needs to be disposed of properly and safely. In this work, an agricultural waste of citrus peel (CP) was used to detoxify COPR by the pyrolysis process, and the resulted residue (DT-COPR) was used as the adsorbent to ...
The raw materials utilized in the industrial application of the pelletized chromite pre-reduction process consist of fine chromite ore, a carbonaceous reducing agent, and a clay binder (Kleynhans et al., 2017a, 2017b, 2016, 2012; Neizel et al., 2013; Beukes, Dawson, and van Zyl, 2010; Naiker, 2007). Samples of metallurgical-grade chromite (<1 mm),
Chromite ore processing residue (COPR) is a toxic and hazardous waste slag created during the manufacture of chromium salt that belongs to HW21 (chromium-containing waste category) in the China ...
resulting from chromite ore processing (COPR) and for creating a material balance for ... tion followed by grinding of the material to < 75 µm. Loss-On-Ignition (LOI) tests (ASTM D 7348-08) were ...
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 …
Experimental smelting of three batches of prereduced chromite raw materials with different degrees of metallization of chromium was conducted in the 0.2 MVA ore-smelting furnace of the Chemical ...
Experiments were conducted to pilot the initial reduction in chromium raw materials using the innovative Hoganas technology in a tunnel furnace. To simulate the process, a gas-fired bogie hearth furnace was employed. Technological containers made of silicon carbide crucibles were utilized. Sixteen different combinations of ore and coal mixtures were employed for the …
SiO2 as flux and CaO as slag modifier in chromite smelting. Colemanite can be approximated by the formula 2CaO.3B 2 O 3 .5H 2 O. Crystal water is released from pure
A Review of Chromite Ore Processing Residue (COPR): Past Practices, Environmental Impact and Potential Remediation Methods November 2014 Current Environmental Engineering 1(2):82-90
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. …
uch residues from chromite ore processing and develop chemical approaches to immobilize mobile species of chromium through vatious chemical means in solid state12. The present investigation, on the other hand, reports an approach to mobilize and extract almost all chromium species contained in COPR. Materials and Methods
Chromite ore processing residue (COPR) storage sites are widely distributed all over the world, causing serious soil and groundwater pollution. However, the differences in soil constituents and properties in different regions are significant, and the dynamic migration and transformation of Cr(VI) in different types of soil under alkaline condition of the COPR site is …
Reduction/immobilization of chromite ore processing residue using composite materials based geopolymer coupled with zero-valent iron Ceram. Int., 44 ( 2018 ), pp. 3454 - 3463, 10.1016/j.ceramint.2017.11.148
Pre-reduced chromite material with low metallization degree 29.02 8.20 0.19 20.31 8.50 12.48 10.38 15.37 — — Pre-reduced chromite material with average metallization degree 26.32 8.22 0.19 19.98 8.20 12.48 8.64 17.22 — — Pre-reduced chromite material with high metallization degree 18.92 8.25 0.13 20.82 7.90 12.32 10.05 22.28 ...
Leaching characteristics of chromium ore processing residue (COPR) for the long term (simulating a 20-year leaching scenario) were investigated using laboratory flow-through column testing with ...
Chrome ore refers to natural deposits containing chromium in its original form. A hard, shiny, and corrosion-resistant metal, chrome ore is usually found in the earth's crust in the form of chromite. Chromite is composed of chromium, iron, and oxygen.Chromium is usually …
In this paper, conventional fluxing of chromite ore in South African operations is discussed, to set the scene, followed by the principles behind fluxing with borates, in this case, specifically …
A process for treating chromite-bearing ores to obtain useful mineral values, especially platinum group metal, therefrom wherein the ore is separated into magnetic and non-magnetic fractions; the non-magnetic fraction, containing a substantial portion of the platinum group metals, is concentrated and smelted to produce a metal layer containing platinum group metals; and the …
Chromite ore is the sole commercial source of chromium which is mainly present in the form of spinel containing multiple metal elements with the chemical formula of (Mg,Fe)(Cr,Al,Fe) 2 O 4 [1,2,3].Depending on its content of Cr 2 O 3 and the mass ratio of Cr/Fe, chromite ore can be used in the fields of metallurgy, chemicals, and refractories. Currently, …
In hydrometallurgy, fusion techniques are considered key in the processing of chromite ore. Salts containing easily ionized elements are often used as flux, which results in solutions with …
Chromite 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 severe health issues …
Chromite Ore Processing Residue was produced in large quantities in various countries and was deposited as backfill material in residential and commercial areas.
the annals of "dunarea de jos" university of galati fascicle ix. metallurgy and materials science . 1 - 2019, issn 2668-4748; e-issn 2668-4756
1 Chromite beneficiation: After the processing procedures such as crushing, screening, grinding, and gravity separation, we process chromite ore into chromite concentrate. 2 Grinding : Use a ball mill or a rod mill to grind the chromite concentrate into a fine powder with a fineness of 200 mesh.
Chromium Ore Processing Residue In this study, two types of COPRs, including GB (unweathered) and HB (weathered) COPRs, were obtained from a fill site at the Dundalk
Fluxing of South African chromite ore with colemanite by M.W. Erwee, I.J. Geldenhuys, M.B. Sitefane, and M. Masipa 03BF7AEA South African chromite ores are smelted using SiO2- and CaO-containing fluxes, normally as quartz and limestone respectively. The purpose of SiO2 is to lower the melting point of the ore, while CaO is added to ensure that the
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