Avoiding large tailings dams without going underground-Robinsky’s thickened tailings concept

Abstract

With the recent high profile failures of the Samarco and Mount Polley tailings dams, governments, environmental groups and mining companies have been looking to alternative methods of tailings storage that are not so reliant on the integrity of large embankment structures. Underground backfill of tailings is an attractive option at first glance, but unfortunately only a partial solution at the best of times; a typical underground mine can only contain a portion of the tailings whilst mining operations are ongoing, whilst a typical open-cut mine has no underground workings to fill. Dry stacking of filtered tailings is another attractive option, but it is relatively expensive in most situations. It is also still developing as a technology, with few large scale operations currently in service. Eli Robinsky’s concept for the surface deposition of thickened tailings is a proven technology with dozens of examples of successful implementation around the world. It is asserted that Robinsky’s thickened tailings concept has been unfairly ignored or dismissed in some parts of the world, resulting in the ongoing construction of many large tailings dams, all of which increase the risk of another major tailings dam failure occurring in future. This paper describes Eli Robinsky’s concepts of Central Thickened Discharge and Down Valley Discharge, and presents some examples that demonstrate how these tailings storage concepts have been successfully applied in dozens of mines around the world. Some indication of the relative disposal cost per tonne for a number of alternative tailings disposal techniques is also presented.