The summary of the Environment Impact Assessment and Environment Management Plan for South Kaliapani Chromite Mining in Sukinda ultramafic complex, Sukinda, Jajpur, Orissa claims that benefits of the project include expansion programme of OMCL, strong employment generation potential, peripheral development and creation of social capital, boost in agricultural sector and increased awareness for education etc.
The pollution from hexavalent chromium whose lies in the chromite mines has turned Sukhinda into one of the world's most polluted places in the world. Waste rock and untreated water from the mines adversely impacts local water supplies. The air and soils in the region is severely contaminated. The health impact on the residents suffer from gastrointestinal bleeding, tuberculosis, and asthma. The cases of infertility and birth defects are common in the area. While routine actions have been taken by mining companies involved. The remediation required a determined state to act to set matters right.
Management of waste dump in Sukinda valley is the major environmental concern. These overburden dumps modify the land topography, affect the drainage system, prevent natural succession of plant growth resulting in acute problems of soil erosion and environmental pollution.
Normally, waste dumps are maintained up to height of 20-30 m with 30 m terrace width and slope angle of 25 to 35 degrees. Toe-wall, garland drain, terracing, plantation along the slope are some common measures being adopted for waste dump management. Neem, Chakunda, Accacia, Mahul, Sal, Mango, Cashew, Arjuna, Babul, Amla, Bahada, Jamun, etc. are the species used in
afforestation over dead dump slopes, dump terrace, along the haul roads and safety zones in the mines. The major source of environmental pollution in Orissa is the hexavalent chromium generation, especially in case of friable ore. The hexavalent chromium contamination of the local water bodies is a major concern because of its carcinogenic properties. The pumped out water from the mine needs to be doused with ferrous sulphate solution before being discharged. This converts hexavalent chromium to trivalent chromium.
Environmental problems related to chromium processing are limited. Chromium, in its trivalent
(Cr3+) oxidation state as found in chromite and other natural minerals, is an essential nutrient. Its principal function is to maintain normal glucose metabolism. Chromium deficiencies can lead to problems in insulin circulation as well as possible risk of cardiovascular disease. Hexavalent form of chromium (Cr 6+) which is used widely in chemical compounds has been implicated in skin rashes and lung cancer.
Karnataka too is endowed with rich deposits of Chromite in Hassan. Chromite ore body extending to 300 m depth is mined by underground method since 1967 at Byrapur in Hassan district of Karnataka. Here cut-and-fill method of stoping is practised.
An area around Thagadur village of Karnataka has grabbed US attention for its chromite reserves. The Mysore Minerals Limited (MML) has three chromite mines in Jamboor, Thagadur and Bhaktarahalli. The mining in these three villages began in the 1990s, soon after the Indian market opened up to the world. The company, which was on the verge of closure due to the entry of private players into granite mining, was directed by the Centre to mine for chromite in Channarayapatna taluk. This opened up new horizons for the sick company. The MML is also hunting for chromite reserves in various places like Moodbidri in Mangalore taluk, Konaje, Karkala and other places. It closed mining operations for the premium ‘Hassan green granite’ as chromite had more profits. A top official of MML said that the company had enough reserves to sustain mining for more than 50 years. “This area is rich with chromite reserves and it is a high value mineral. All the three sites are export oriented units, the only such status given to all the mining operations taken up by the MML,” said the official.
He said that the company had only one bulk chromite buyer in Gujarat, which uses it for pharmaceutical purposes. The final product of chromite — florouracil and methotrexate — are used for the production of chemotherapy drugs by some top pharmaceutical companies in the US. “Our Gujarat-based agent told us that there are many uses of the downstream projects which have been kept out of the public domain,” said the official.
Another engineer of the company said that long distance underground and undersea cables for high speed transmission of data, voice and codes too use a great deal of chromite downstream products.
DNA newspaper reported on December 8, 2010 that B N Varaprasad Reddy, tahsildar, Channarayapatna has informed that MML was meeting all the safety measures as stipulated by the Indian Mining Act. The demand for chromite saw an annual increase of 4% between 2000 and 2008, with ferrochrome consumption increasing by the same amount. However, the onset of the economic downturn from mid-2008 saw the demand for chromite plummet.
It is strange that the newspaper did not deem it appropriate to check with the villagers, Karnataka Pollution Control Board, environmental groups or the local leaders.
Chromite is an oxide of chromium and iron. Chromite is the only commercial source of chromium. It occurs as a primary mineral of ultrabasic igneous rocks and is normally associated with peridotite, pyroxenite, dunite and serpentinite. World-wide, high-alumina chromite, largely from podiform deposits is used in refractory applications while iron-rich ores, largely from stratiform deposits are utilised in metallurgical and chemical applications. As per UNFC system, total resources of chromite in the country as on 1.4.2005 are estimated at 213 million tonnes, comprising 66 million tonnes reserves (31%) and 147 million tonnes remaining resources (69%). More than 95% resources of chromite are located in Orissa, mostly in the Sukinda valley in Cuttack and Jajpur districts. Minor deposits are scattered over Manipur, Karnataka, Jharkhand, Maharashtra, Tamil Nadu and Andhra Pradesh.
Orissa continued to be the major producing State of chromite, accounting for 99.85 % of the total production during 2007-08 and the remaining 0.15% was reported from Karnataka. The average daily employment of labour in chromite mines during 2007-08 was 5,371 as against 6,157 in the previous year. Chromite is mined mostly by opencast method in the country. In Orissa Mining Corporation (OMC)'s opencast mines, the bench height is less than 6 m and the bench width is more than 10 m in mechanised quarry. Underground mines are confined to Byrapur in Karnataka and Boula and Kathpal mines in Orissa. In Sukinda valley, chromite has been mined to a maximum depth of about 63 m by open cast method. The maximum overburden to ore ratio is 15:1. In Sukinda area, deposits of chromite lying below 100 m depth may have to be exploited by highly specialised underground mining techniques.
OMC's chromite mines at Kaliapani, Sukrangi, Kalarangi, Kathpal and Bangur, all in Orissa, make it one of the leading chromite producers of the country. Chrome ore of very high grade is produced here. The chrome ore beneficiation plant at Kaliapani with a total production capacity of 84,000 tonnes concentrates is designed to upgrade low-grade ore. Keeping in view the increasing demand for chrome concentrates, OMC is in the process of doubling the capacity of this plant. Transportation of the ore from mines to railway sidings is done through trucks and from railway sidings to various consuming centres by railway wagons.
The reported consumption of chromite in the organised sector increased by 6% from 1,784,800 tonnes in 2006-07 to 1,889,400 tonnes in 2007-08. It was mostly in ferro-alloys/charge-chrome industry.
In metallurgy, chromite is used in the manufacture of chromium metal and various alloys with iron, nickel, cobalt, tungsten, molybdenum, etc. Chromium imparts additional strength, hardness and toughness to its alloys. It also shows resistance to corrosion to steel abrasion, reduces oxidation and flow of electricity. Stainless steel, high-speed tool steel, corrosion and heat resistant steel are some important varieties of chromium steel. Ferro-chrome is of two types: (i) high carbon (containing 4-8% carbon) and (ii) low carbon (containing up to 2% carbon). The amount of chromium used in steel varies with the purpose. Low chromium steels (less than 5% chromium and small amount of nickel) are used in rails, automobiles, armour plates, armour piercing projectiles, etc. Intermediate chromium steels are used in high-speed tools, valves for engines and other equipment requiring resistance to abrasion, corrosion and oxidation. Chromium steels include stainless steels (12-18% Cr) and super-stainless steels (12-30% Cr and 7-10% Ni) which are used for cutlery and cooking utensils and in aircraft and high-speed trains, respectively. Chromium (17%) with iron (83%) is also used as ferritic stainless steel to manufacture coins.
Chromite is used in refractory industry because of its resistance to corrosion, high temperature and ability to withstand sudden temperature changes, and its chemically neutral character. The ore is used in the form of lumps, bricks or cement in linings, specially of steel furnaces. Chromite is used for manufacturing important chromium compounds like chromates and bichromates of sodium and potassium, chromium pigments like chromic oxide green and chromic acid which, in
turn, are used in chromium-plating solution.
Important loading stations for chromite in the country are Jajpur-Keonjhar Road in Orissa and Tiptur in Karnataka. Export of chromite is through Paradip port. However, small quantities of lumpy chromite ore are imported to meet the needs of ferro-alloys industry in the country.
Development of substitutes of chromium customer appeal of the chromium. There are no substitutes in the stainless steel or super-alloys. Boron, manganese, nickel and molybdenum can be substituted in alloy steels and cast irons. Base metal alloys can sometimes be used in place of stainless steel. Dolomite is an alternative for some refractory bricks. Cadmium yellow is one of the several alternative pigments. However, it is not environmentally acceptable and nickel and zinc are possible substitutes for the protection of decorative coatings.
An Expert Committee constituted by the Ministry of Steel, Government of India recommended the need of detailed exploration in all the potential areas in Orissa, Karnataka and ophiolite belt of North-Eastern region with a view to prognosticate resources to a depth of 500 m in Sukinda belt
and estimation of resources in all other potential areas. One does not know whether the Expert Committee will examine the substitutes of Chromite.
Chromium is a hard, bluishmetallic element (Cr) with an atomic number of 24. Chromium was discovered in an ore that geologists now call chromite (FeCr2O4, ferrous chromic oxide). Chromite is formed in an igneous environment.
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