Chromite

The element magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr2O4).

[7] Chromite today is mined particularly to make stainless steel through the production of ferrochrome (FeCr), which is an iron-chromium alloy.

[8] Chromite grains are commonly found in large mafic igneous intrusions such as the Bushveld in South Africa and India.

Chromite is iron-black in color with a metallic luster, a dark brown streak and a hardness on the Mohs scale of 5.5.

The chromite minerals occur in layered formations that can be hundreds of kilometres long and a few meters thick.

[12] Chromite contains Mg, ferrous iron [Fe(II)], Al and trace amounts of Ti.

Stratiform deposits in layered intrusions are the main source of chromite resources and are found in South Africa, Canada, Finland, and Madagascar.

The mafic to ultramafic igneous provinces that these deposits are formed in were likely intruded into continental crust, which may have contained granites or gneisses.

Chromitite is the main rock in these layers, with 50–95% of it being made of chromite and the rest being composed of olivine, orthopyroxene, plagioclase, clinopyroxene, and the various alteration products of these minerals.

The stratigraphy of the ophiolite sequence is deep-ocean sediments, pillow lavas, sheeted dykes, gabbros and ultramafic tectonites.

[19] Chromium extracted from chromite is used on a large scale in many industries, including metallurgy, electroplating, paints, tanning, and paper production.

Chromite concentrate, when combined with a reductant such as coal or coke and a high temperature furnace can produce ferrochrome.

Introducing a definitive control approach and distinct mitigation techniques can provide importance related to the safety of human health.

When chromite ore is exposed to aboveground conditions, Cr-III can be converted to Cr-VI, which is the hexavalent state of chromium.

[24] As a result of leaching of soils and the explicit discharge from industrial activities, weathering of rocks that contain chromium will enter the water column.

[25] Plant studies have shown that toxic effects on plants from chromium include things such as wilting, narrow leaves, delayed or reduced growth, a decrease in chlorophyll production, damage to root membranes, small root systems, death and many more.

[25] During industrial activities and production things such as sediment, water, soil, and air all become polluted and contaminated with chromium.

[23] In aquatic environments, chromium could experience things such as dissolution, sorption, precipitation, oxidation, reduction, and desorption.

These toxic effects will operate differently because things such as sex, size, and the development stage of an organism may vary.

Things such as the temperature of the water, its alkalinity, salinity, pH, and other contaminants will also impact these toxic effects on organisms.

[26] The chromium extracted from chromite is used in chrome plating and alloying for production of corrosion resistant superalloys, nichrome, and stainless steel.

This is used for things such as nonferrous alloys, the production of stainless steel, chemicals that process leather, and the creation of pigments.

Superalloys that contain chromium allow jet engines to run under high stress, in a chemically oxidizing environment, and in high-temperature situations.

The usual contributor to colour in fast-fired porcelain tiles is black (Fe,Cr)2O3 pigment, which is fairly expensive and is synthetic.

Natural chromite allows for an inexpensive and inorganic pigmentation alternative to the expensive (Fe,Cr)2O3 and allows for the microstructure and mechanical properties of the tiles to not be substantially altered or modified when introduced.

A chromite prospect in Yukon . The black bands are chromite, which also carries platinum group metals . Gray rock is bleached ultramafics .
Bushveld Chromite
Chromitite band in chromitic serpentinite