Remediation of hexavalent chromium contamination in chromite ore

1. 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 …

Chromium (Cr) Ore | Minerals, Formation, Deposits …

Overall, the mining and processing of chromium ore require specialized techniques and processes to extract and concentrate chromite, followed by smelting and refining to produce ferrochrome, …

A cleaner method for preparation of chromium oxide from chromite ore

The new process includes pressurized leaching of chromium ore, separation of Na 2 CrO 4 from leaching solution and preparation of chrome oxide green (Cr 2 O 3) from intermediate barium chromate (BaCrO 4) in series. This process achieves the direct cycling of concentrated alkali liquor, greatly enhancing its economic value and …

Chromite ore beneficiation: prospects and challenges

The mining process generates two types of ore—hard/lumpy and soft/friable. The mined high-grade lumpy ores are directed to ferro chrome plant after suitable sizing …

Chromium Processing | Process Flow, Cases

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 …

Phase transformation of Cr (VI) host-mineral driven by citric …

1. Introduction. Chromite ore processing residue-contaminated soils (COPR-soil), containing large amounts of highly mobile and carcinogenic hexavalent chromium (Cr(VI)) [17], [24], pose a serious threat to ecological safety and public health.Chemical reduction is the most widely used method because of its economic feasibility and …

The soda-ash roasting of chromite ore processing residue for …

Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr2O3 cannot be extracted after chromite sodium roasting ...

Chromium Ore Processing Residue

Allied Chemical Company, which operated the plant until its closing in 1986. The plant refined chromium ore and produced industrial materials used in steel products, leather tanning, paint and miscellaneous other products. A byproduct of the refining process was a soil like residue generally identified as COPR.

KPMG commodity insights bulletin chromite

Chromite. Chromite is the commercial name of iron chromium oxide (FeCr2O4), a mineral comprised of chromium and iron oxide that is naturally found in the earth's mantle. When extracted, it is referred to as chrome ore. Chromite is crucial for the production of ferrochrome, an alloying agent in manufacturing stainless steel.

Extraction of Chromium from Chromite Ore

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 …

Chromium (VI) Retrieval from Chromium Ore Processing

"Chromite ore processing residue" (COPR) is a typical waste from the chromium metal industry. Chromium production started in the first part of the nineteenth century and has been increasing ever since, particularly for use in the production of stainless steel and a wide range of other materials (Blazy and Hermant 2014).The …

Chrome steel from chromium ore processing residue

T1 - Chrome steel from chromium ore processing residue. AU - Kamolpornwijit, Wiwat. AU - Meegoda, Jay N. PY - 2011. Y1 - 2011. N2 - In Hudson County, New Jersey, there are more than two million tons of leftover chromite ore processing residues (COPR). Part of COPR was used as construction fill materials spreading the problem to a larger area.

Commercial Extraction Technology and Process Waste

Chromium ore processing residue (COPR) has been deposited at a site in the North of England, probably at the end of the nineteenth century. The site covers an area of approximately 2.2 ha, and is ...

Chromite: The only mineral ore of chromium …

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 …

Stabilization of chromium ore processing residue (COPR) …

Consequently, chromium contaminant in groundwater, chromium ore processing residue (COPR), and sediment represents a significant environmental and public health concern [9]. The U.S. EPA maximum contaminant level (MCL) for total chromium in water is 0.1 mg/L [10]. Chromium in natural waters exists primarily in +3 …

Green manufacturing process of chromium compounds

In the process of carbonate leaching, the chromium-containing residue after magnesium extraction can be used as iron ore or raw material in the cement industry . In addition, aluminum in chromite ore can be extracted and recovered in the green process as aluminum hydroxide [Al(OH) 3 ].

Stabilization of chromium ore processing residue (COPR) …

DOI: 10.1016/J.JHAZMAT.2005.09.008 Corpus ID: 12378454; Stabilization of chromium ore processing residue (COPR) with nanoscale iron particles. @article{Cao2006StabilizationOC, title={Stabilization of chromium ore processing residue (COPR) with nanoscale iron particles.}, author={Jiasheng Cao and Wei‐xian Zhang}, …

Chemical beneficiation of chromite ore to improve the chromium …

The conventional ore-fed SAFs process recovers 68–75% of Cr from chromite ore, while the DC arc process recovers ∼ 90%. Therefore, hypothetically, chromite ore subjected to the proposed pelletized pre-reduction condition that results in a Cr recovery of 80% or less after leaching, could have an ultimate Cr recovery of 70% or …

Chromium Processing | Process Flow, Cases

Chemical Formula. (Fe, Mg)Cr2O4. Streak. Brown. Mohs Hardness. 5.5. Crystal System. Isometric. Color. Black to brownish black; brown to brownish black on thin edges in transmitted light. Luster. …

Mineral processing: leaching process of chromium and

The present study provides a useful set of data on the production of basic chromium sulphate from chromite ore. The percent yield of sodium chromate is strongly …

Chromite Ore

Magnetic and Electrostatic Separation. In Mineral Processing Design and Operations (Second Edition), 2016. Chromites [FeCr 2 O 4]. Chromite is an end member of a complete solid solution series between naturally occurring chromites contain iron and magnesium as substituting impurities with chromium oxide.

Stabilization of chromium ore processing residue (COPR) with nanoscale

Consequently, chromium contaminant in groundwater, chromium ore processing residue (COPR), and sediment represents a significant environmental and public health concern [9]. The U.S. EPA maximum contaminant level (MCL) for total chromium in water is 0.1 mg/L [10].Chromium in natural waters exists primarily in +3 …

Sufficient extraction of Cr from chromium ore processing …

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 …

Chromium processing | Extraction, Uses & Applications

Chromite deposits are mined by both underground and surface techniques. Much of the ore is rich enough to be used directly: for … See more

Reduction and immobilization of hexavalent chromium in chromite ore

1. Introduction. Hexavalent chromium (Cr(VI)) is highly mobile, severely toxic (Shahid et al., 2017) and highly carcinogenic to humans (IARC, 2010).Chromite ore processing residue (COPR) is a type of hazardous industrial waste (Mills et al., 2017; Moon et al., 2008; Wu et al., 2015) that contains a large amount of residual Cr (2000–40,000 …

Water/acid/reductive biomass leaching of Cr(VI) in chromium ore …

1. Introduction. Chromium ore processing residue (COPR) is the solid waste obtained from the production of chromium metal and chromium salt, mainly from the process of preparing sodium dichromate by calcium roasting method (Li et al., 2019; Senko et al., 2014; Zhang et al., 2009).For every 1 t of chromium salt and metal, 2–3 t and …

A detoxification and value-added process for chromium ore processing

Chromium ore processing residue (COPR), containing much virulent hexavalent chromium [Cr(VI)], is a by-product derived from chromate production. Fe-C-bearing dust from steel industry is very difficult to be utilized effectively because of its complex composition and unstable properties. The dust was co-processed with COPR by …

Vertical migration in the soil of Cr(VI) and chromite ore processing

1. 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 …

Immobilization of chromium ore processing residue by …

Chromium ore processing residue (COPR) is classified as hazardous solid waste because of the leachable Cr(VI). Cementitious materials are often used to solidify and stabilize heavy metals. However, most of them focus on the leaching concentration of particles after solidification and stabilization and lack research on leaching …