Environment, Mining and Sustainable Development in Lead-Zinc Mines —An Observation

摘要

Mining, either opencast or underground, is invariably considered as an environmentally unfriendly activity as it affects many components of the environment. The lead-zinc mining operation with inadequate pollution control measures can also contributes significantly the environmental degradation. The present paper is focused on environment hazards and their control measures adopted by open cast lead zinc mines including ore beneficiation. The major environmental hazards are dust, mine water and waste water, tailing dam, hazardous waste product, blast vibration and noise. The major source of above hazards are drilling, hauling, crushing, concentrate yards, transportation, mine pit water, seepage from tailing dam, concentrate spillage, oil and grease from heavy earth moving workshop, vibration during mine blasts, and hazardous chemical consumption in ore beneficiation. The major control measures adopted are wet drilling operations with dust collection system, spray of dust suppression chemical mixed water on haul roads to minimize the fugitive dust generation, spray jet nozzles on crusher with wet scrubbing system, dust extraction (DE) fans at coarse ore stock piles (COSP) with ventury system, covered conveyor belt, retention of 8-9% moisture in concentrated ore, which is further stored at sheltered stock yards, pumping of tailings with 20% solids to tailing dam and recycling of supernatant water back to ore beneficiation process, construction of reclaim reservoir for the storage of recycled water from tailing dam, mine pit and other runoff collecting sumps around the mine and waste dumps, installation of hydro cyclones for effective water recovery during beneficiation process, construction of garland drains around the waste dumps to channel the waste dump runoff water which is further collected in runoff collecting sumps, plantation on inactive waste dumps with gunny bag filled plantation methodology, installation of sewage treatment plants at residential colony and plant area, extensive plantation within mine lease and outside mine lease area, storage of hazardous waste (HW) product and mine waste rocks at earmarked area and the recycling of HW product to registered recycler. With these measures the Pb- Zn mines will be able to get sustainable development and keep the healthy environment.