In a bid to minimise adverse environmental impact, Coal India (CIL) is looking to undertake several measures, including ramping up of underground mining operations and focusing on green mining options by leveraging a slew of eco-friendly technologies in its underground (UG) and opencast (OC) mines.
The country’s largest miner is looking to ramp up UG production by four-fold to 100 million tonnes (mt) by FY30 from 25.6 mt in FY22. The UG output is environmentally clean, minimally invasive on land degradation and society friendly. Around 70 per cent of the country’s coal reserves are conducive for UG mining.
“The aim is to enable UG production to sizably supplement the OC output. At the current rate, mineable coal reserves at existing OC will slowly start lowering,” said a senior company official.
Since the nationalisation in 1975, the output from underground mines had has contracted by nearly 58 per cent till FY22, while production from opencast mines expanded 8.5 times.
What tilted the scales
Loss incurring production, longer gestation period, lack of skilled labour, unavailability of indigenous equipment and high cost of departmental production were some of the reasons that tilted the scales against UG mines.
“With multiple options available now, UG production could become viable. Important among them are — mass production technologies, availability of indigenous manufacturing units and well trained skilled labour. Outsourcing to contractors would also scale down the cost of production. Gestation period is also considerably lower now. With these advantages, CIL plans to steadily scale up the locked up UG coal assets,” the official said.
Use of technology in OC mines
Land is considered to be a major pain point for expansion of coal mining operations, but the use of eco-friendly technologies could help bypass land acquisition and avoid its degradation. The locked up coal assets left out earlier due to techno-commercial and safety concerns can now be unearthed through these technologies, he said.
Among mass production technologies, CIL plans to introduce 50 continuous miners by FY25 with peak production potential of 25 mt a year. As many as 21 such machines are already deployed in ECL, CCL and SECL producing 9 mt a year.
Two powered support long wall (PSLW) machines operating in ECL and BCCL produced 1.58 mt in FY22 against 1.13 mt in FY21 posting a 40 per cent growth. Two more PSLWs with a total capacity of 4.5 mt a year are soon to be deployed in BCCL.
Mining through punch entry
In a first, CIL is aiming to mine through punch entry in those OC mines which have reached their ultimate pit level. It plans to identify and implement five such mines through punch entry in phased manner till FY24., so that mineable assets can be extracted with economic viability.
It is also planning to deploy ten high wall machines in its OC mines during the ongoing fiscal with projected production potential of 5 mt annually. This would entail a total capex of around ₹2,000 crore.
CIL is also planning to use paste-fill technology, which is yet another environment friendly frontier that involves high speed stowing technology. This will be compatible with mass production technology. In contrast to conventional sand stowing, it uses fly ash to fill the void created by extracting coal from UG mines. Such system is in advanced stage of implementation in ECL.
June 17, 2022