Push for hi-tech as underground coal mining gains focus

India is becoming a high-cost mining destination as underground coal mining is gaining huge importance with open cast reserves depleting quickly.

According to Rajesh Nath, managing director of the German Engineering Federation or VDMA, India would now have to opt for high-cost technology, as it has to shift focus from open cast to underground mining. Till recently, India?s coal requirement was met by open cast mines and Indian mining companies did not have to look for high-cost technology.

West Bengal chief minister Buddhadeb Bhattacharjee, who inaugurated the 9 th International Mining and Machinery Exhibition here on Wednesday, said underground mining accounts for only 13% of India?s total coal mining. With demand for coal rising to match the same of the country?s growing power sector, coal miners would have to look for reserves deep under the ground, as open cast reserves are depleting.

According to Coal India officials, underground mining in India is done at a maximum depth of 625 metres at the Chinakuri mine in Raniganj coalfield area under Eastern Coalfields Ltd using the long wall technology. Chinakuri is also the deepest mine in Asia.

Hartmut Schauerts, Germany?s deputy minister for federal ministry of economics & technology, said: ?Germany has the technology to mine at a depth of 1700 metres at 57 degree rock temperature. So if India?s needs are to go beyond 625-650 meters, that is not an impossibility.?

?However, such technologies are costly and India now needs to think in terms of availing those,? Schauerts said.

According to experts, if technology for going beyond a depth of 650 metres is available, the West Bengal government?s proposal to develop Aerotropolis or an airport in Andal on 3,500 acres becomes unviable as coal is sure to be available there at a depth of 800 metres. CIL chairman Partha S Bhattacharyya, who attended the IMME- 2008, told reporters that CIL has engaged the Central Mine & Planning Design Institute to estimate reserves in Andal and at the depth those are available. It will submit the report to the state government within seven days. ?The state, considering the CMPDI study, will take the decision,? Bhattacharyya said.

CMPDI officials on the condition of anonimity told FE that the coal seam in the porposed airport area starts at a depth of 70 metres and an estimated reserve of 2,355 million tonne is available between the depth of 70–800 metres. There are five blocks?Tamla, Ichapur, Nachon, Daskhin and Moina-Khandra?quite close to the porposed airport area and if the long wall mining technology is used to mine coal from the blocks, the horizontal extension would overlap the proposed airport area.

In fact, all the five blocks have been earmarked for underground mining and coal production, and the Planning Commission?s estimate for the 12 th Plan Period takes into account the production from these blocks, CMPDI officials said. Mining activities in a patch called Moira is going on 500 metres from the proposed airport site and according to CMPDI estimates, mining in that patch can continue for 25 years. However, if the airport comes up, mining aictivities have to be stopped. CIL officials said India is a country that uses the most efficient technology. But for going at a depth beyond 600 meteres, its horizontal expansion would be so large that land required for operatring one block would be three times more than that of the block area.