कोयला मंत्रालय
Gainful Utilization of Overburden (OB) – To Promote Circular Economy (Waste to Wealth)
Even as the mandate is to produce and despatch coal to its consumers, Coal/Lignite PSUs has taken an out of box initiative to produce sand from overburdenat a much cheaper price and usages of processed OB for stowing purpose. This will not only help in minimising environmental pollution due to sand siltation from overburden, but will be also an option for getting cheaper sand for construction purpose. Production of sand has already started.
During opencast mining of coal, the strata lying above coal seam is known as overburden comprising of clay alluvial sand and sandstone with rich silica content. The overburden is removed to expose and extract coal from beneath. After completion of coal extraction, the overburden is used for back filling to reclaim the land in its original shape. While extracting overburden from top, swell factor of the volume accounts for 20-25%. Initiative has been taken to utilise at least 25% of overburden in converting to sand by crushing, sieving and cleaning.
The very first initiative of such conversion has been taken by Western Coalfields Ltd.(WCL), a subsidiary of CIL in its mines. Initially a Pilot Project was launched where sand was extracted through machines erected departmentally. This sand has been offered to Nagpur Improvement Trust at a much cheaper price for constructing low-cost houses under Pradhan MantriAwaasYojana (PMAY). The price of sand is almost 10% of the market price with better quality. On huge success of the project and with growing demand of cheaper sand, WCL launched commercial production by commissioning the largest sand production plant of the country near Nagpur. This unit produces 2500 cubic metre of sand per day at about half the market price. Major chunk of the sand produced from this plant is being given to Govt. units such as NHAI, MOIL, Mahagenco and other smaller units at one third of the market price. Rest of the sand is being sold through open auction in the market which is helping locals to get sand at a much cheaper price. The use of overburden has minimised the volume of land required for overburden dump. This initiative also lowers the adverse footprint of river bed mining of sand. WCL is also selling overburden for road construction at a cheaper price to NHAI & others.
In this effort to Promote Circular Economy (Waste to Wealth), Coal/Lignite PSUs has commissioned 4 Nos of OB processing plants and 5 Nos of OB to M-sand Plants. Six Nos of OB processing/ OB to M-sand plants are in the different stages of installation in the Coal/Lignite PSUs. Two plants are expected to commission in FY 2024-25.
Processed Overburden Plant at Gonegaom Area by WCL & at Srirampur OC Mines by SCCL
