Technical and economic indicators of a slurry tailings hydrotransport system when replacing steel slurry lines with polyurethane-coated slurry lines

Abstract

The hydrotransport system of Andrei Varichev Mikhailovsky GOK JSC used for iron ore processing tailings was studied with the aim of establishing its performance when using slurry pipelines with and without polyurethane coatings of their internal surfaces under mass concentration variations of 10 to 70 %. It has been established that the use of internal polyurethane coatings significantly reduces the specific head losses in hydraulic transportation of thickened slurry tailings for iron ore processing tailings. However, the technical and economic calculations performed failed to confirm the economic efficiency of their application for the slurry pipelines of the tailings facility hydrotransport system of Mikhailovsky GOK at any slurry thickening values, due to the significant payback period of capital investments caused by the relatively high current cost of polyurethanecoated pipelines. At the same time, a significant reduction (almost by a factor of four, provided that the current production volumes are maintained) in hydrotransport (energy) costs and maintenance costs of pressure slurry pipelines were identified for a transition to slurry tailings thickening to 50 % solids (excluding the capital and operating costs for the thickening system, reconstruction of the slurry pumping stations and additional measures for the distribution of a thicker slurry at the tailings storage facility). It is proposed to use the results obtained in the reconstruction of the slurry tailings hydrotransport system at the tailings facility of Mikhailovsky GOK with a conversion to hydraulic transportation of bulk concentration tailings thickened to 50 % in ∅820 mm slurry pipelines.