- Chromite is
found in peridotite and other layered ultramafic intrusive rocks and
also found in metamorphic rocks such as serpentinites. Ore deposits of
chromite form as early magmatic differentiates. It is commonly
associated with olivine, magnetite, serpentine, and corundum. The vast
Bushveld igneous complex of South Africa is a large layered
igneous body with some layers consisting of 90% chromite making the rare
rock type, chromitite.Chromite is also used as a refractory material.
- Chromite forms in
deep ultra-mafic magmas and is one of the first minerals to crystallize.
It is because of this fact that chromite is found in some concentrated
ore bodies. While the magma is slowly cooling inside the Earth's crust,
chromite crsytals are forming and because of their density, fall to the
bottom and are concentrated there.
- The cleaner
process of sodium dichromate production by roasting chromite with
lime and leaching with sodium bicarbonate solution under the
pressure of carbon dioxide was investigated. The roasting reaction
conversion effectiveness attained 82.5% under the conditions CaO/Cr2O3
= 2, 7000C, 3 hours. The amount of residue after leaching decreased
as 1/3 of traditional process. The equation concentration of sodium
dichromate in leached solution attained 100g/L(Cr6+) under 1.3MPa of
carbon dioxide pressure and 500C.
- The traditional
production process of chromates was roasting chromite with sodium
carbonate and some additives containing calcium at above 11000C -
water leaching - acidification with sulfuric acid. The waste and
pollution were serous in the process, as one ton sodium dichromate
was produced, about 3-4 tons toxic chromium-containing residue,
10-20m3 toxic chromium-containing waste water, 1.5 ´ 104 m3 waste
gas, 0.8 ton toxic chromium-containing sodium sulfite and 0.2 ton
toxic chromium-containing aluminum hydroxide were discharged, it
was high-cost to treat these waste.
- Chromite grains
in thin sections from 11 samples were analyzed to determine their
major- and minor-element compositions. Samples were selected that
contained chromite as an early liquidus phase. Analyses were made at
the University of New Mexicoʼs microbeam facilities using a JEOL JXA
8200 microprobe equipped with a back-scattered electron detector, a
thin-window energy dispersive spectrometer, and fi ve
- The chromite sand
shows a higher thermal conductivity. It is used where an additional
cooling effect should be reached (cooling or chill effect). The
disadvantages are similar to the negative characteristics of
zirconium sand, caused by the high bulk density. Due to the angular
shape of the grains chromite sand leads to a higher tool wear and a
higher demand of binder
- While Chromite
mining in India started there was no ferro-chrome production
in the country till. Hence most of the chromite ore was exported.
India exported about 3.84 million tonnes . The current production
rate of chromite ore in the country is between 0.7 to 0.9 million
tonnes per annum. Later, India attained a production of 90,000
tonnes of FeCr/charge chrome.
- Prior to
implementation of the OMCAL, and FACOR units, the production of FeCr
was only about 20,000 TPA. The situation has changed dramatically
due to the commencement of production in the export oriented units.
Estimated reserve of chromite ore in the country is about 140
million tones, and about 127 million tones are available in the
Sukinda valley of Orissa state.
- Tata Steel Ltd.
and Orissa Mining Corp. Ltd. proposed a joint venture on chromite
mining in the Sukinda Valley in Orissa. Orissa Mining held more than
80% of the mining lease in the valley, which totaled 4,700 hectares
(ha); Tata Steel held 406 ha. Tata Steel would be responsible for
chromite mining, preparing chromite ore and concentrates for export,
and production of value-added materials, such as ferrochrome. Tata
Steel took over the operation of Orissa Mining’s Sukinda ferrochrome
plant and other ferroalloys plants in Orissa
Entrepreneur who wants
the informations on "General Information, Manufacturing Technology, Applications,
Patent, Consultants, Company Profiles, Reports, Market, Projects,
Properties, Plant, Guides" can
Email as to