Remediation of Cr(VI)-contaminated soil mixed with chromite ore …

Chromite ore processing residue (COPR) is a major contaminant of Cr(VI)-contaminated soil. It is a by-product of chromium salt during the lime-based roasting process, which was estimated to be nearly 6 million tons in 2004 and has increased by 60,000 tons annually in China (Liu et al., 2020).

Remediation of Cr(VI)-contaminated soil mixed with chromite ore …

Chromite ore processing residue (COPR) is a major contaminant of Cr(VI)-contaminated soil. It is a by-product of chromium salt during the lime-based roasting process, which was estimated to be nearly 6 million tons in 2004 and has increased by 60,000 tons annually in China ( Liu et al., 2020 ).

Chromium processing | Extraction, Uses & Applications

chromium. 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 corrosion, resulting in its application as an electroplated protective coating for other metals.

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

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 been …

Chromite | Chromium Ore, Properties, Uses and Occurrence

Chrome iron ore : Chromic iron : Ferrichromite - magnetic, altered : ICSD 20819 : PDF 34-140 ... View Additional jPOWD Structure files for Chromite : Physical Properties of …

Co-treatment of chromite ore processing residue and …

1. 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 and less …

Chromite Mineral Data

Chrome iron ore : Chromic iron : Ferrichromite - magnetic, altered : ICSD 20819 : PDF 34-140 ... View Additional jPOWD Structure files for Chromite : Physical Properties of Chromite ... Optical Properties of Chromite : Gladstone-Dale: CI meas= 0.092 (Poor) - where the CI = ...

A clean and efficient leaching process for chromite ore

In summary, the following kinetic equation can be applied to describe the pressure leaching process for chromite ore in 50 wt% KOH solution: (3) 1 - ( 1 - x) 1 / 3 = 20537 × ( P O 2) 1.16 × e - 64020 RT × t. The reaction activity of KOH solution decreases significantly with the decrease of KOH concentration, while the oxygen solubility and ...

Chrome ore beneficiation challenges & opportunities – A …

Introduction. Chromium is one of the modern industry's essential element and important raw material for the production of special steel and ferrochrome alloys. Around …

Chromite

The main consumers of chromite ore are the ferroalloy, refractory, and chemical industries, which have different demands for the ore and the concentrates, both in terms of the …

Chromite (chr) | SpringerLink

Chromite, chr, is the main chromium ore, and when Cr-poor, it still finds application as a refractory. The FeCr 2 O 4 composition ideally attributed to chromite (Fe 2+ Cr 2 O 4, according to IMA) is usually not exactly that of most natural chromites, which cover a wide compositional range in the Spinel Subgroup (Oxyspinel Group/Spinel ...

Chromite | Ores, Mining, Processing | Britannica

Chromite, relatively hard, metallic, black oxide mineral of chromium and iron (FeCr2O4) that is the chief commercial source of chromium. It is the principal member of the spinel series of chromium oxides; the other …

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

Chromite ore processing residue (COPR) keeps releasing Cr(VI) over time, and the mixing of residual COPR into soil makes the remediation of COPR-contaminated sites challenging. In this study, a sample of COPR and two soil profiles were collected from a typical historical COPR-contaminated site, and the vertical migration of Cr(VI) and …

Chromite ore beneficiation: prospects and challenges

Almost pure chromite is found in similar layers in sedimentary rocks. The layers are preserved when the sedimentary rocks metamorphose to form serpentinite …

Chromite: Mineral information, data and localities.

Isostructural with: Magnesiochromite, Magnetite. Chromite is the most important chromium ore mineral. It forms a complete solid solution series with many other members of the …

Chromite: The mineral Chromite information and pictures

Chromite, the principle ore of the element chromium, is a commercially valuable mineral. However, due to mining restrictions and the fact that Chromite is not commonly found in …

Review of Chromite Ore Processing Residue (COPR): Past …

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 …

A new metallurgical process for the clean utilization of chromite ore …

The chromite ore samples exploited from Philippines were obtained from Bluestar Yima Chrome Chemical Materials Co. Ltd., PR China. The chemical analysis of a typical sample by ICP-OES was given in Table 1.Prior to the experiments, the sample was crushed and dry-sieved to four particle-size fractions (0.045–0.063, 0.063–0.075, …

Chromite- mineralogy and processing

High-aluminium chromite ores with relatively low iron and silica are used mainly for refractories; chromite refractory bricks are used in the lining of steel-making furnaces. 150 140 130 120 110 IO0 90 80 B 70 50~ 40 A 30 20 10 70 75 80 85 year Fig.1 Annual prices of chromite: A - 44% Cr203 South African ore, low (1.5-2:1) Cr:Fe ratio); …

Chromium Ore

8.2.1 Chromium Minerals Overview. Knowledge of the chromium ore minerals proper and their associated rocks-forming minerals is needed to explore new chromite fields and to predict the efficiency of individual methods for the beneficiation of chromite ores. It is important also to know the physicochemical properties of individual mineral ...

Chromite: The mineral Chromite information and pictures

The Mineral chromite. Chromite, the principle ore of the element chromium, is a commercially valuable mineral. However, due to mining restrictions and the fact that Chromite is not commonly found in crystallized form, it is not well-represented in mineral collections. Chromite is isomorphous with the mineral Magnesiochromite and is easily ...

Chromite ore beneficiation: prospects and challenges

Idiomorphic chromite is the only ore mineral appearing in economic quantities. The average content of the ore is 26% Cr 2 O 3 and the Cr/Fe ratio is 1.55. The Kemi chromium mine is an open-pit mine with a waste rock to ore ratio of 5.5:1. At Kemi, the ore from the mine contains 11% iron and 25.5% Cr 2 O 3.

Chromium Data Sheet

Chromite ore (gross weight) 216 198 259 279 270 Ferrochromium (chromium content)3 2,606 2,227 3,212 2,933 2,200 Chromium metal (gross weight) 11,386 9,827 9,682 11,344 11,000 Stocks, yearend, held by U.S. consumers 8 8 8 8 8 Net import reliance4 as a percentage of apparent consumption 64 64 70 73 72

Chromium Ore, Chromite, Properties, Uses, Distribution Map

Chromium Ore. Chromium is a critical alloying metal. It is used in the production of alloys with other metals such as nickel, cobalt, copper, and others, as well as in many other metallurgical, refractory, and chemical industries. Chromium increases the strength, hardness, and toughness of its alloys. Chromite (Cr) is the only commercially ...

Chromite Ore | EverQuest 2 Wiki | Fandom

aITEM -1630080840 925028587:Chromite Ore/a aITEM -1630080840 925028587:Chromite Ore/a What does this information mean? EverQuest 2 Wiki. Explore. Main Page; All Pages; Community; Interactive Maps; ... View history Talk (0) In-Game Examine Window Chromite Ore. other resources; EQ2U · LootDB · EQ2LL · ZAM · …

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.

Kinetic Study on the Smelting Reduction of Bottom-injected Chromite Ore …

Pulverized Chromite ore has been injected into 20kg of carbon containing iron melt from the bottom of crucible, so that the ore is reduced by the dissolved carbon. The effects of temperature, ore injection rate, flow rate of gas and particle size of the ore on the chromium yield and reduction rate have been examined.The chromium yield increases linearly with …

Chromite ore processing residue in Hudson County, New …

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 bichromate chemical manufacturing. At least 15% of the sites contain total chromium concentrations greater than 10,000 mg/kg, with hexavalent …

Chromite: Mineral information, data and localities.

Chromite is the most important chromium ore mineral. It forms a complete solid solution series with many other members of the group, eg. in the Chromite-Hercynite Series, Chromite-Spinel Series, Chromite-Magnetite Series and the Chromite-Magnesiochromite Series.It is the iron analogue of Zincochromite, Cochromite, Manganochromite and …