Operation of Surface Miner: Retrospect of a Decade Journey in India

摘要

Surface miners made their debut in Indian surface mining industry in 1996 on a limestone deposit. The application of surface miner was extended for coal mining in the year 1999. Presently, more than 100 surface miners are working in Indian surface mines owing to its higher productivity and environment-friendliness. Presently, surface miner is also experimented for excavation of different deposits, namely, bauxite, hematite, sandstone, shale etc. Initially, the surface miners were being deployed largely on trial and error basis or on the basis of in-field experimental runs. Manufacturers evaluated the applicability of surface miners based on compressive strength of rock. Recently, a cuttability index has been developed to predict the applicability and performance of surface miners for different application condition. This enables the user to select a suitable machine as per their requirement. Surface miner completely eliminates drilling blasting and primary crushing unit and thus reduces their associated environmental hazards. Apart from this, the sized excavated material increases the transport/conveying efficiency and thus saves the energy requirement in transportation. Application of surface miner with proper planning yields better efficiency. The planning can be categorized into two parts, namely, short term and long term planning. Short term planning is within the control of field engineer and is carried out to achieve the steady production rate and quality control. Short term planning is carried out to select the operating mode, place of operation etc. Surface miner can allow a steep slope angle. As the blasting (short term stress) is eliminated the factor of safety for the pit slope can be kept low. This reduces the stripping ratio and increases the overall productivity of the mine. These are the essential consideration for long term planning with surface miner. This present paper would discuss the Indian experience of surface miner operation on the above issues. The benefits of the deployment and the challenges faced during operation have been discussed in this paper. The recent research and development carried out in this area is also highlighted.