(6)Double Effect CAVEX: The End Solution in Sand Classification and Water Saving for Tailings Dam

摘要

Over the last decade, the mining industry has tried different ways to dispose of the tailingsgenerated as a result of mineral processing, heap pads, filling of closed mine shafts and, the mostfrequent reason, dam construction through the classification of sands coming from the same tailingsmaterial. Whatever the alternative, water recovery is a key element in the viability of the project,due mainly to the water shortage challenging countries worldwide and the importance that waterholds as a necessity good. For each of the above options, it is of primary importance to have waterrecovery equipment in place and provide the tailings quality required for the deposition orclassification of wall construction sands. The double-effect CAVEX has proved to be the bestalternative to achieve this objective.Double classification has a direct impact on separation efficiency as it is beneficial for fines andwater recovery purposes, in global terms. In order to produce sand of a certain required quality, thedouble classification helps reduce dramatically the amount of fine material entrained by coarsematerial -that might be achieved with a single classification stage- and, at the same time, helpsimprove even further the global water recovery in the process. Only one stage is needed, free of anyextra infrastructure to complete it, such as pumping, tanks, and the required power to conveyslurry between stages.CAVEX-DE has proved its capacity and flexibility in different mine sites in Chile, Peru, and Brazil.In the classification of wall construction sands, optimal results have been obtained for a wide rangeof solids concentrations and particle sizes. The results have been as expected, with minimum waterconsumption, as compared to current technologies.