Design solution for the thin-layer separation effect use of the suspension when washing metal-bearing sand at placer deposits

Abstract

The technical solution for the thin-layer apparatus structures’ use in technological processes of polymineral sands enrichment as applied to alluvial deposits development is considered. Characteristic features of technological processes at sand washing, requirements to the equipment in mobile variant and comparative estimation of possibilities on typical thin-layer analogues’ use in extreme operating conditions of enrichment complexes of washing devices type are given. It is shown that massproduced thin-layer devices do not meet the specific requirements both in weight and dimensions and in absence of enrichment features to capture small and thin classes of valuable component from the resulting suspension flow. Proposed new technical solution of the apparatus on the basis of large diameter pipes has allowed to reduce the total weight and dimensions of the structure many times, which gave them a transportability factor with frequent change of washing locations. The adopted longitudinal configuration of the device makes it possible to set the double-thin-layer effect of separation of the suspension’s two-phase medium, which is used to form an enrichment function. Testing of prototypes in the production environment has shown that the use of hardware design process of water treatment based on the proposed thin-layer devices makes it possible to return 80–90% of process water to the turnover, bypassing the environmentally unstable groundwater sediment ponds. Physical modeling has shown that the design with two-contour flows of sediment layer additionally forms the effect of particle segregation with the subsequent lower part of the localized sludge cutting off. At the same time the technological efficiency of heavy fractions’ enrichment is provided up to 79,1% according to Hancock-Luiken formula.