(2)Alternatives to Tailings Dams in Mining Operations

摘要

Over the last 90 years, Chilean mining tailings have been hydraulically deposited in confineddeposits.. More than 10 significant disasters have occurred during this period, resulting in the lossof human lives and the incurrence of high cost material damages. The incorporation ofimprovements in the design, operation, and control of these deposits began only in the 1960s (as aconsequence of the Tranque El Cobre disaster).Over the last few decades, both design and operational practices have notably improved, giving theimpression that the technology of dams has already been clearly established and completelyaccepted by authorities and communities. .A recent court ruling against Minera Los Pelambres for its Tranque Mauro declared the dam an“obra ruinosa” which translates to a “condemned facility” in English. In addition, a portion of theCaimanes community has strong conflicts with this deposit, with an uncertain outcome. Theprecedent set by this dam could radically change the outlook for obtaining approvals for new dams,especially in the central zone of Chile.In this context, a thorough analysis of whether it is possible for the Chilean mining industry tooperate without tailings dams is highly relevant, and constitutes the subject of this presentation.In the author's opinion, at least five operational models exist for the operation of sulphides miningfacilities without the use of tailings dams. These models include:In site sulphides leaching.Sea Tailings Disposal (STD).Filtration of the tailings and disposal in cake form.Dispose of the tailings as paste (over 65% solid by weight) in beaches with 2% to 5% slopes andsmall cut-off walls.WLM (Minería Integral Sin Residuos), a method developed by JRI, patent in development.For each of these options, a description of the method, a SWOT analysis, and the potential for use asa medium and long term solution is presented.