Semi-dry tailings dump stability management

The article presents an assessment of the risk level of a hydrodynamic accident at a tailings dump using the “fault tree” method, and the results of engineering studies of the spatial-temporal change in the physical and mechanical properties of a dump of semi-dry tailings of cyanidation cakes. It was established that as a result of laying tailings in thin layers of 2 to 5 m, freezing them in the winter period and consolidation of the man-made massif, their humidity decreased, density and strength characteristics increased. The unique experience of implementing scientific and technical solutions for making the dump of semi-dry tailings on an inclined waterproof base is presented. The implementation of those solutions has allowed to double the total dump capacity. The risk level of a hydrodynamic accident has been reduced by eliminating the negative impact of hydrostatic and hydrodynamic forces on the dam. The dam stability has been ensured at a seismic intensity of 8 points in the area with a coefficient greater than the standard (with a probability of collapse of no more than 2.9%) due to a special measure to increase the shear resistance along the base of the dump. The results of the research and ten years of experience in the operation of a semi-dry tailings dump can be useful to design and operating organizations when placing tailings storage facilities in limited areas in the northern climate zone.