Rock-engineering strategies to meet the safety and production needs of the South African mining industry in the 21st century

摘要

During the past two to three years, the South African mining industiy has experienced the most difficult years of its existence. These difficulties have arisen because of poor commodity prices, rising costs, low grades, and productivity and safety problems. The safety and, to a lesser extent, productivity problems arise largely as a result of the high stresses imposed on deep-level excavations. Fracturing of the rock generally occurs in a controlled manner, but sporadic violent failures can suddenly disrupt mining activities and occasionally injure or cause the death of workers. For example, up to 67 per cent of the fatalities and 30 per cent of the injuries on mines are due to rock-related accidents. These problems are endemic to mining at moderate depths, but are likely to be particularly severe at very deep levels and to aggravate the already high costs associated with deep mines if advances are not made in the design of improved stress-tolerant layouts, better support systems, and more-efficient mining methods. This paper addresses the potential for current and future developments in rock engineering to enable the gold- and platinum-mining industry to mine more productively and safely at depths ranging from the current average depth of about 1600 m to future depths of 4000 m. Examples of mining projects that have been delayed but would benefit from improved rock-engineering technology include the following: Mines of shallow to medium depth: Weltevreden Gold Mine Northam Platinum Mine Deep to ultra-deep mines: Target Project Sun Project Moab extension to Vaal Reefs South Deep Strathmore area.