Mine Closure Planning in Indian Coal Mines Optimization of solid waste dumps Vis-a-vis Land Requirement -A case Study

摘要

Mining essentially creates an imbalance in natural equilibrium due to excavation activities and mainly causes disturbance to land use pattern and ecosystems such as seasonal nallahs, flora & fauna. Mining either by underground methods or Open cut method will imbalance eco system and especially land use pattern. SCCL is major coal producing company in south India having 42 UG Mines and 11 opencast mines and exploiting coal for the last 100 years. More than 70% coal is exploited by opencast method and annual coal production is 37.7million tones. This paper deals with the various methods being followed in India with an emphasis on Mine closure planning and solid waste management methodology followed in surface coal mines of SCCL.Surface mining creates voids at the end of mine life and creates visual impact to environmental aesthesis. This imbalance in original eco system needs to be balanced by following proper Mine Closure planning. Surface mining operations needs to remove the overburden (surface soil) and dumping or storing huge volumes on ground up to a height of 90m in three stages of heights at 30m intervals. These dumps are basically two types viz Internal Waste dumps, External waste dumps. The basic purpose of internal waste dumps is to fill the voids created due to mining operations and to restore surface profile for use after completion of mining activity. However, it is not possible to fill all the waste rock back into voids and will be stacked at some place called as External waste dumps. The Mine closure planning is a method being followed in surface mines of SCCL (Godavari Valley Coal fields) before closure of mines to establish minimal damage to environment. The paper deals with assessment of external solid waste dump lands and estimation of the land required for solid waste produced due to mining activity and effect of coal bearing strata gradient on filling back filling of void and further to restore land to its original shape by allocation of funds at planning stage.