Hydraulic-fill construction and operation of a tailings pond

Abstract

1. As shown by the experience with operation of tailings ponds [5, 6] formed by the hydraulic-fill method with dispersed sludge discharge, the construction of stable toes in the tailings pond is ensured. 2. Underwater hydraulic-fill placement of tailings having more than 70% of particles smaller than 0.074 mm is not recommended. In exceptional cases, underwater hydraulic-fill placement of such tailings may be carried out only after smoothing the irregularities, pits, trenches, and ditches, and only when further grading of the zone is performed whether with subsequent above-water hydraulic filling or by other (dry) methods applied with mining engineering reworking, as well as when there are no structures and no new projects are to be constructed in the zone. 3. Use of the relations described above makes it possible to determine the distribution of the particles and the regimens of hydraulic-fill placement of fine tailings in a tailings pond for dispersed sludge discharge, and is effectively confirmed in industrial practice. For example, for the tailings obtained from the processing of sulfur ores at the Rozdol'sk Mining-Chemical Combine [7], which contain particles smaller than 0.074 mm in amounts of 75–85%, the rate of hydraulic-fill placement of stable toes is 2.5–3.5 m/yr, whereas in the case of hydraulic filling of patterns for stockpiling of limestones fertilizers under a forced regimen the rate is 6–7 m/yr, which indicates the potentialities of the hydraulic-fill techniques. This will make it possible to increase the volume of stockpiling and shipping of mineral fertilizers of the combine to 3 million tons per year, that is, to increase the production of these limestones by a factor of almost two and to obtain a significant economic effect on account of a reduction in the contingent-fixed costs and other expenditures.