Use of cement to reduce erosion of the slopes of mine tailings dams

Abstract

Erosion on the slopes of mine tailings represents one of the most important environmental problems arising from the disposal of mine tailings. Tailings dam erosion is the main source of pollution that contaminates agricultural land and streams around mining areas. There is an urgent need to reduce erosion of the slopes of mine tailings in-order to limit further devastation of natural ecology. The present study investigates the possible use of cement to reduce erosion of the slopes of mine tailings dams. The pinhole erosion test was used to measure erodibility of tailings stabilized with cement. The strength properties of cement-stabilized tailings have been evaluated by the unconfined compression test. Conbex and ordinary Portland cement have been used for tailings stabilization, with contents of 0, 3, 5, 7, and 10% by mass. It has been established that cement can be used to reduce erosion of the slopes of mine tailings dams. At least 3% by mass cement is required to produce zero erosion loss. The resistance of tailings to erosion can be enhanced by increasing compaction density, curing period and cement content. Ordinary Portland cement produced higher strengths and erosion resistance than Conbex, although Conbex may be useful for stabilizing fine tailings. Cement-stabilized tailings could be used to make bricks and rubble for use in reducing erosion of the slopes of mine tailings dams. As little as 10% of cement is necessary to produce unconfined compressive strengths of 1600- 2600 kPa.