Design of a lined platinum tailings storage facility in South Africa

Abstract

Under current environmental legislation in South Africa, tailings are viewed as potentially hazardous waste that needs to be disposed of in compliance with the appropriate minimum requirements. The platinum tailings in this case study were classified as a hazardous waste, requiring a geomembrane as a key component of the pollution control barrier for disposal. Traditionally, tailings dams in South Africa have been built on top of the in-situ soils. The use of composite liners is relatively new in tailings dam construction in South Africa and brings with it its own set of challenges. For example: where before the natural drainage through the in-situ soils aided drainage of the tailings dam, all drainage must now take place through engineered systems, stability of the tailings dam needs to be assessed considering potential weak planes caused by the barrier system, and management of stormwater during construction must be carefully planned. This paper presents a case study highlighting how some of these challenges were addressed in a project where a composite liner was included in the design of the tailings dam.