Slurry Transportation of iron ore
A notable development in transportation is slurry transport of fine ore concentrate in pipelines. The first such pipeline (225 mm diameter) was put into operation in Tasmania (Australia) for transporting 2.25 Mt of magnetite concentrate over a distance of 85Kms. It is generally preferred when other modes of transport are cost prohibitive. M/s Kudremukh Iron Ore Company, India, is transporting by slurry pipeline about 7.5 Mt of fine ore concentrates from Kudremukh to Mangalore over a distance of 65 Kms.
ENVIRONMENTAL IMPACTS – OPEN CAST IRON ORE mining
It is recognised that minerals and metals are the mainstay of the economic development and welfare of the society. However, their exploration, excavation and mineral processing directly infringe upon and affect the other natural resources like land, water, air, flora and fauna, which are to be conserved and optimally utilized in a sustainable manner. The mineral sector in India is on the threshold of expansion with more and more open cast iron ore mines being opened-up in the state of Jharkhand, Orissa, Karnataka and Chattisgarh. Under such scenario, systematic and scientific exploitation of iron ore, compatible with environment is essential for survival of our future generation.
Mining being site specific activity, excavation is bound to be done at a place where mineral actually exist. Hence, the mining process changes the landuse of the area and is of no use to the mining companies once mineral is exhausted completely. In the process, mining affects all the components of environment and the impacts are permanent/temporary, beneficial/harmful, repairable/irreparable, and reversible/irreversible. Mines especially open cast iron ore mines, due to its own peculiarities can cause disturbance in ecology, resulting in various pollution problems. The environmental problems are more significant in India, as most of the iron ore mines located on top of hills and in dense forest areas.
The environmental problems associated with the iron ore mining are diverse. The removal of vegetation, top soil, overburden/waste and ore, brings about the inevitable natural consequences, which manifest in many ways, deforestation, climatic change, erosion, air and water pollution and health hazards. Iron ore mining and processing of ore, affects the environment in myriad ways causing:
Land disturbance and change in land use pattern
1. Affecting floral and faunal habitat
2. Disturbing the natural watershed and drainage pattern of the area
3. Disturbing the aquifer causing lowering of the water table
4. Air pollution due to dust and noxious fumes
5. Water pollution due to surface run off from different areas of mines, spoil dumps, seepages/overflow from tailings dam leads to siltation of surface water bodies and blanketing the agricultural fields.
6. Noise and ground vibrations due to blasting.
7. Socio-economic impacts
The magnitude and significance of these impacts on environment and ecology due to mining will depend on the size and scale of mining activity in conjunction with the topography & climatic conditions of the area, the nature of mineral deposits, method of mining & capacity of mines, agricultural activities in the region, forest reserves etc.
A line diagram showing various unit operations of iron ore mines and its associated environmental aspects.