Indian mine operator Sainik Mining and Allied Services, contractor to the country’s (and one of the world’s) largest coal producer Coal India Ltd (CIL), operates a total of 21 Wirtgen surface miners. Ten 2200 SMs are in operation in the 530-km2 Gevra mine in the province of Chhattisgarh. Wirtgen Group says its local subsidiary’s “excellent customer service has tradition: individually tailored service contracts used to guarantee security in planning and coal mining operation for several years already.”
The vertical coal seams in the Gevra mine require a selective mining method. Additionally, 90% of the cut coal ought to have a maximum particle size of 100 mm. This is why, since 1999, the mine operators have gradually switched mining activities from drilling and blasting to Wirtgen surface mining. Currently, 80% of the coal is already being mined using this environmentally friendly technique, another 20% still via conventional methods. The mine operators are planning, however, to shift to 100% surface mining of coal within the next two years. In Gevra, surface mining has proven to be clean, safe and more environmentally friendly as well.
In the mine, windrowing proved to be the optimal mining method. Using this technique, it is easier to check the material quality. Additionally, coal can be mined in the most economical way. With windrowing, the cut coal is placed directly behind the machine, between the crawlers, without the use of a loading conveyor. This allows material to be cut independently of the loading process – although the coal has to be loaded separately via wheel loader later. As a result, each 2200 SM – with a cutting width of 3.8 m and a cutting depth of 300 mm – can mine roughly 15,000 t/d of coal. The annual capacity of the coal mine is 80 Mt, 90% of which is thermal coal for power generation in local plants. Wirtgen says its surface miners “are the ideal solution to mine the large deposit of over 10,000 Mt as efficiently as possible.”
The service contract especially tailored to the Gevra mine guarantees that two experienced Wirtgen engineers are available there all the time during operation. They provide support for all necessary maintenance activities relating to the surface mining fleet, including machine repairs, preventive maintenance measures, inspection of certain machine parts, training of machine operators, etc. The Wirtgen experts also make sure that all spare parts needed are being kept on stock.
India is the third largest coal producer in the world.