chromite processing cr fe

Genesis of chromite deposits by dynamic upgrading of Fe …

We propose a new process that involves partial melting of Fe ± Ti oxide–rich rocks (oxide-facies iron formation or ferrogabbro) and conversion of fine-grained oxide to chromite by reaction with Cr-rich komatiitic magma in a dynamic magma conduit. This process is analogous to the widely accepted model for the upgrading of barren iron-sulfide ...

Hydrogarnet: A Host Phase for Cr (VI) in Chromite Ore Processing …

Effect of Coexisting Fe(III) (oxyhydr)oxides on Cr(VI) Reduction by Fe(II)-Bearing Clay Minerals. Environmental Science & Technology 2019, ... Leaching kinetics of acid-soluble Cr(VI) from chromite ore processing residue with hydrofluoric acid. Journal of Central South University of Technology 2011, 18, 399-405. DOI: 10.1007/s11771-011 …

Smelting Process of Chromite Ore Fines to Produce Crude Fe–Cr–Ni–N

The smelting behavior of waste chromite ore fines containing Cr and Ni to produce crude Fe–Cr–Ni–N alloy was investigated in this study. In the experiments, for each heat, liquid steel melt (metal pool 1 kg) was prepared in a 3--capacity laboratory-scale electric arc furnace for the absorption of reduced metals like chromium, nickel, etc., …

Chrome ore beneficiation challenges

This 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 beneficiation.

Magnetic separation studies on ferruginous chromite …

richment (i.e., increased Cr:Fe ratio) of a chromite sample from the Aladag concentrator, Turkey using a high-intensity dry magnetic separator resulted in a product with 49.1wt%

Improving the Quality of Ferruginous Chromite Concentrates …

In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium-to-iron ratio. …

Microstructural analyses of Cr(VI) speciation in chromite ore

1. Introduction. 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.

Visible Light Accelerates Cr(III) Release and Oxidation in Cr–Fe

The reduced chromite ore processing residue (rCOPR) deposited in environments is susceptible to surrounding factors and causes reoccurrence of Cr(VI). However, the impact of natural sunlight on the stability of rCOPR is still unexplored. Herein, we investigated the dissolution and transformation behaviors of Cr(III)–Fe(III) hydroxide, …

Efficient immobilization and utilization of chromite ore processing …

1. Introduction. The natural mineral chromite is widely utilized by high-lime roasting technique to obtain chromate products due to the needs of leather, catalysis, metallurgy and other industries, in which a large amount of chromite ore processing residue (COPR) is produced (Dermatas et al., 2006; He and Traina, 2005).A small …

(PDF) Chromite. Processing and Applications

In the paper are shown the history, processing and applications of chromite. Chromite is an oxide of iron and chromium with the chemical composition FeO.Cr2O3 and belonging to the spinel group.

Valorization From Waste: Combined Reduction of Chromite Ore Processing

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 …

Mechanism of the Direct Reduction of Chromite Process as a …

With the new knowledge, the mechanism of DRC can be described as (1) incongruent dissolution of chromite, (2) reduction of Cr in molten slag, (3) transport of Cr and Fe …

Efficient reduction of Cr(VI) and recovery of Fe from …

Under optimal conditions (i.e., the Na 2 CO 3 dosing of 0.5 mol/L, the molasses/COPR mass ratio of 10%, hydrothermal treatment at 140 °C for 150 min), the …

Efficient immobilization and utilization of chromite ore …

Chromite ore processing residue (COPR) has been a severe environmental contaminant which is worthy of attention. In this study, we developed an eco-friendly and …

Cleaner Production of Chromium Oxide from Low Fe(II)-Chromite

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 …

Improving the Quality of Ferruginous Chromite Concentrates Via Physical

The achievable Cr:Fe ratio of the concentrates varies from 1.5 to 2.8 from a low-grade deposit with Cr:Fe ratios of 0.5 to 1.0 by using gravity separation [4,10,11,12,13]. There are few published data available about processing low-grade deposits or tailings in order to beneficiate chromite.

(PDF) A Process Mineralogical Evaluation of Chromite at …

The chromite chemistry evolved from being Cr-rich in the massive ores to being more iron-rich in the disseminated ore types. This is consistent with a decreasing Cr/Fe ratio from the massive ore to disseminated ore types (Figure 5). Minerals 2020, 10, 709 12 of 27 Figure 5. Cr-Al-Fe3+ ternary plot based on chromite cation proportions.

Mechanism of the Direct Reduction of Chromite Process as …

Direct reduction of chromite (DRC) is a promising alternative process for ferrochrome production with the potential to significantly reduce energy consumption and greenhouse gas emissions compared to conventional smelting. In DRC, chromium (Cr) and iron (Fe) from chromite ore incongruently dissolve into a molten salt, which facilitates mass …

Visible Light Accelerates Cr(III) Release and Oxidation in Cr-Fe

Visible Light Accelerates Cr(III) Release and …

X-ray absorption near-edge structure and density functional theory analyses reveal that coexisting Fe in the solid plays a critical role in the pH-dependent release and transformation of Cr(III), where …

Visible Light Accelerates Cr(III) Release and Oxidation in Cr-Fe

The reduced chromite ore processing residue (rCOPR) deposited in environments is susceptible to surrounding factors and causes reoccurrence of Cr(VI). However, the impact of natural sunlight on the stability of rCOPR is still unexplored. ... (III) Release and Oxidation in Cr-Fe Chromite Residues: An Overlooked Risk of Cr(VI) …

Efficient reduction of Cr(VI) and recovery of Fe from chromite …

DOI: 10.1016/j.eti.2023.103046 Corpus ID: 256607791; Efficient reduction of Cr(VI) and recovery of Fe from chromite ore processing residue by waste biomass @article{Tian2023EfficientRO, title={Efficient reduction of Cr(VI) and recovery of Fe from chromite ore processing residue by waste biomass}, author={Hong Tian and Lanbin …

Chemical beneficiation of chromite ore to improve the …

The chromium (Cr) content of stainless steel originates from recycled scrap and/or ferrochrome (FeCr), which is produced mainly by the carbothermic reduction of chromite ore.

Mechanism of the Direct Reduction of Chromite Process as …

As our working hypothesis, it is contemplated that the CaCl 2-assisted DRC process involves incongruent dissolution of chromite in molten CaCl 2 followed by in situ reduction and metallization of Fe and Cr species on solid carbon particles. 8−10 There are, however, significant gaps in knowledge on the kinetics and mechanism of the DRC …

Visible Light Accelerates Cr(III) Release and Oxidation in Cr …

Our study provides a new insight into Cr (VI) reoccurrence in rCOPR and helps in predicting its environmental risk in nature. Keywords: Cr (III)−Fe (III) hydroxides; …

Microstructural Analyses of Cr(VI) Speciation in Chromite …

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 …

Smelting Process of Chromite Ore Fines to Produce Crude Fe–Cr–Ni–N

The optimum process conditions are as follows: the mixing ratio of stainless steel dust to chromium containing slag is 94%: 6%, the reduction temperature is 1400°C, the reduction time is 25 min ...

Pyrolysis Treatment of Chromite Ore Processing Residue by …

The pyrolysis treatment with biomass is a promising technology for the remediation of chromite-ore-processing residue (COPR). However, the mechanism of this process is still unclear. In this study, the behavior of pyrolysis reduction of Cr(VI) by cellulose, the main component of biomass, was elucidated. The results showed that the …

Top 3 Chrome Ore Processing Methods that Get Higher …

Chrome ore chemical beneficiation One of the purposes of chemical beneficiation is to increase the Cr/Fe ratio of the chromite concentrate produced by the physical methods, and the other purpose is to treat certain chromium ores that cannot be treated by physical methods or that are uneconomical by physical methods.. The …