Permeability Characteristics of Sedimentary Fine Tailings Including the Degree of Compaction

Abstract

Tailings dam accidents can result in serious casualties and environmental problems. Therefore, it is necessary to analyze the factors affecting the safety of tailings dams. In this paper, the permeability characteristics of sedimentary fine tailings, including the degree of compaction, and the seepage failure of tailings dams are explored. The results indicate that the permeability coefficient gradually decreases with increasing fine-particle content. There is a threshold associated with the fine-particle content at which the trend in the coefficient changes. The fine-particle content at this threshold is 35% for particles finer than 0.075 mm and 15% and 30% for particles finer than 0.005 mm. At a given fine-particle content, the permeability coefficient of horizontal sampling tailings is the largest, followed by that of uniform tailings, with the permeability coefficient of vertical sampling tailings being the smallest. When low pressure is applied to tailings containing fewer fine particles, even though the pores are reduced in size, they are still connected. Only under high-pressure conditions can the connectivity of the pores of tailings containing few fine particles be reduced. When the fine-particle content increases, the fine particles fill the spaces between the coarse particles. Low-pressure conditions can then reduce the connectivity of the pores.