Tailings ponds are one of the three major production facilities in metal mines. The volume of tailings increases year by year, but the storage capacity of existing tailings ponds is limited. Therefore, tailings dams must become more fine-grained and larger. The potential hazard they represent should not be underestimated. This paper reveals the causes and regional distribution patterns of 342 tailings dam failures globally from 1915 to 2021 through statistical analysis. It was found that tailings pond failures occur almost every year, with an average of 4.4 accidents/year (1947–2021). The frequency has been gradually increasing in recent years, and most tailings pond failures are directly related to heavy rainfall or earthquakes. The frequency of tailings pond failures was significantly higher in Asia (21.3%) and the Americas (57.9%), especially in China (n = 43) and the United States (n = 107). Causes of tailings pond failures differed among regions. Most tailings pond failures in Asia and Europe were related to hydroclimate, while those in South America were mainly triggered by earthquakes. This study will provide theoretical data for the pre-design as well as the safe and stable operation of global tailings ponds, which will help to prevent global tailings pond failures.
24 July 2021 in Rock Mechanics and Rock Engineering
In this paper, the effect of high temperature on the mechanical properties of quartz-rich sandstone was studied by true triaxial pressure experiment. The density, P-wave velocity, elastic modulus, peak stress, peak strain, and failure mode of quartz-rich sandstone before and after heat treatment were analyzed and compared. It was found that the color of quartz-rich sandstone changes greatly when heated to 500°C. In detail, the brittleness of quartz-rich sandstone gradually decreased and the ductility increased at high temperature. Although the density, P-wave velocity, and elastic modulus fluctuate, they showed a decreasing trend as a whole. In addition, the peak stress and peak strain showed an overall upward trend with the increase of temperature, and 500°C was the high-temperature failure threshold of quartz-rich sandstone. The failure mode of quartz-rich sandstone at high temperature changes from shear failure to shear-tension combined failure, and the number of cracks increases. Therefore, these research results can provide a certain reference for high-temperature underground operation.