Underground mining with backfills

Abstract

The mining industry worldwide has typically not conducted the development of mines with the overall design objective of a safe, environmentally sound and aesthetically satisfactory post~operational mine~site. Mine waste has typically not been engineered to any large degree but has rather been disposed of in the easiest or most cost effective manner with little (if any) regards for the social and/or environmental consequences. The backfilling of mines is an integral part of the mining process and requires the same level of attention generally afforded to the more commonly recognised "profit-producing" parts of the operation. The change in perception of backfilling from an additional cost to mining operations to one of a pre~profit activity will aid the required advancement in technology required for backfills. Backfilling is required for the continuance and efficiency of mining operations. Additional benefits include: improved regional and local roek stability through the support provided by the backfill, reduced costs of building significant tailings disposal structures on the surface, and the reduced environmental impacts by the underground containment of waste material. All these focus the operation towards the overall design objective of a safe, environmentally sound and aesthetically satisfactory post-operational mine-site. With these objectives in m.ind, the purpose of this paper is to highlight the basic geotechnical issues regarding underground mining with backfills, following new developments by the Australian mining industry.