Surface Mining Technology: Progress and Prospects

Surface mining methods dominate the world production of minerals. Currently, almost all non-metallic minerals more than 95%, most metallic minerals more than 90% and a large fraction of coal more than 60 percent are mined by surface methods. Of the over 30 billion tonnes of ore and waste materials that are mined each year, surface mining accounts for nearly 25 billion tonnes. The subsurface of the earth is the only source for fossil energy and mineral products, and mining is the only way to get at them. There is a wide variety of surface mining methods. The operations of drilling, blasting, loading and hauling are common to most methods. Technological developments over the years have enabled the application of surface methods to deeper and leaner deposits. Also common to all methods is the removal of the surface cover over the deposit, the changes to the original topography, the effects on soil and hydrologic conditions, the issues of mining and processing wastes, and the effect on the future economic potential of the mined areas and communities. However, the scope of the issues and the potential solutions to the issues vary widely and are often site-specific. While research and development are needed to address technical aspects associated with these issues, innovative policies for addressing the overall problem of environmental and ecological planning for post-mining development on lands with mineral resources are needed. In the last two decades, the mining industry has seen consolidation of operating companies, growth in the size of individual operations, increase in size of equipment, and greater demands for sustainable development. These trends would continue into the future impacting both the opening of new mines and the closure of existing operations. In this paper, an overview of surface mining technology is presented. The discussion follows the mineral development cycle and concludes with an identification of future research needs.