Barmer Lignite Mining Company Limited (BLMCL) sets example of water stewardship by reusing mine waste-water post RO treatment
Raj WestPower Limited (RWPL), a subsidiary of JSW Energy Limited, is a 1050 MW thermal power plant located in the Bhadresh Village, Barmer District of Rajasthan. Lignite is the main fuel used in this power plant. Barmer Lignite Mining Company Limited (BLMCL) supplies lignite from its captive mines of Jalipa and Kapurdi that is located around 5 kms from the power plant.
Apart from attaining zero liquid discharge in its operations, the power plant has taken a step ahead and implemented the process of reusing mine waste water generated form the BLMCL mines. The poor quality mining wastewater generated from the mines need to be handled with care. Mining wastewater is rich in heavy metals, hydrocarbons, grease and solids, and these foreign particles must be processed/removed, prior to their discharge into the environment. Through an investment of 29.4 Cr the plant has commissioned an RO treatment unit for treatment of mine waste water.
The following are the steps in Mine waste water treatment and reuse
Step 1: Mine waste water generated each day (25,000 m3/day) is pumped into the raw water reservoir and is stored there before treatment. The total dissolved solids of mine waste water is around 20000 to 25000 PPM.
Step 2: Waste water is sent to the pre-treatment units where chlorine, antiscalant agents and acids are mixed into the waste water to prepare it for reverse osmosis. Post the pre-treatment water is pumped into the RO units which consists of 2 stages. Daily treatment capacity of the plant is 15,000 m3/day.
Step 3: 10,000 m3/day of RO treated water is transferred to power plant reservoir through pipeline to be used in the power plant as raw water. The treated water has a total dissolved solid of 200 to 250 PPM, which is equivalent to the fresh raw water received. 5,000 m3/day of RO reject is pumped to the solar pond for natural evaporation.
Through the RO treatment of waste water, 10,000 m3/day of water is available for recycling and reuse thus reducing the freshwater intake of the plant by 18%.
Through this initiative, the plant has put in serious efforts for water conservation and reuse. The efforts are also in line with the United Nations Sustainable Development Goals (UNSDGs) 9 & 12.