Cement, Energy and Environment

feasible to con nue processing. Different materials have different proper es that determine a feasible cut-off grade. O en these grades are set at over- conserva ve levels. The easiest way to improve efficiency in mining and to reduce waste products is to decrease the mill cut-off grade of the mine. Re- evalua ng these grades at each mine will significantly reduce waste. A lower mill cut-off grade may decrease the quality of the material, but certain final uses of the material do not need a very pure compound. Cut-off grades will be determined on a mine-by- mine basis by looking at the precedents for the material in ques on and taking the future use of the material into considera on. For example, the above men oned recent R&D study done by NCCBM, has very encouraging results in terms of re-evalua ng the MgO (Magnesia) content in Limestone for Clinker manufacturing, which earlier assumed to be less than 3.5%. Three types of high MgO clinker samples were obtained and designated as Clinker-1 (MgO~6.2%), Clinker-2 (MgO~6.8%) and Clinker-3 (MgO~7.5%). PPC & PSC got succeeded in Clinker-1 & Clinker-2 in all respect, while tes ng with OPC autoclave expansion was observed. The performance results obtained so far are quite encouraging which will pave the way for u liza on of low grade limestone containing high MgO, increased mine life (~15 years) besides improved sustainability during cement manufacture. This will also add to the u lisa on of waste material of mine, thus leading to sustainable mining prac ces. · Replenishing the environment A seemingly simple step, but it is rarely priori zed, replenishing mine sites and mine environment is one of the key factors to not only earning respect and coopera on of those living surrounding the mine site, but it will also ul mately protect the mine's impact on the environment. Mining companies some mes overlook the importance of replenishing the environment. This simple act can go a long way towards increasing the environmental sustainability of mining. It has simple solu ons like replenishing na ve soils and grasses, cleaning excess waste, proper waste removal, site inspec ons, replan ng trees and natural forestry. By restoring the environment around the mine, the mining companies are contribu ng to posi ve environmental change, rather than making the environment more difficult to live in. The en re mine reclama on process should combine removal of hazardous materials, reshaping land, restoring topsoil, and plan ng na ve grasses, trees or ground cover natural to the site. The New Mineral Policy emphasized that all mining shall be undertaken within the parameters of a comprehensive Sustainable Development Framework which will ensure that environmental, economic and social considera ons are integrated effec vely in all decisions of mines and mineral issues. The Guiding principal shall be that a miner shall leave the mining area in an ecological shape which is as good as it was before the commencement of mining or be er with least impact on flora and fauna of the area. · Improving environmental performance It is well known fact that mining ac vity impacts the environment in unnatural ways, which not only disrupts its natural decaying process, but also does more damage long-term than natural erosion processes. With exorbitant numbers of materials excavated and used daily, it is important to see that this 17