Research on the Inhibition of Bacterial Oxidation of Pyrite and Concomitant Acid Mine Drainage Part 1. Investigations on Gold Mine Sand Dumps

Concern about the production in mine waste dumps of acid drainage water containing high levels of sulphate and metal ions initiated the research of this project into the possibility of chemically inhibiting the bacteria responsible for the acid formation in the dumps. Research in the U.S.A. indicated that such treatment of dumps might be effective. Two types of dump have been investigated, namely, gold mine sand dumps and coal waste dumps. The project involved a contract of the Water Reseach Commission (responsible for finances) with the Department of Microbiology and the Institute for Polymer Science of the University of Stellenbosch (responsible for the research of the project) and the Chamber of Mines of South Africa (responsible for providing pilot scale experimental coal waste dumps and support services, including routine chemical analyses). The investigation was divided into two phases, namely, Phase I, comprising laboratory studies at the University of Stellenbosch, and Phase II, consisting of the pilot scale tests of chemical inhibitors on coal waste dumps, involving the Department of Microbiology at the University of Stellenbosch and the Chamber of Mines. The present final project report has been divided into three parts: Part 1 comprises all studies on the gold mine sand dumps (Phase I, Department of Microbiology), Part 2 all studies on coal waste dumps (Phases I and II, Department of Microbiology and Chamber of Mines) and Part 3 all studies on the development of slowrelease systems for the inhibitor sodium lauryl sulphate (Phase I, Institute for Polymer Science). The remainder of this executive summary refers only to Part 1 of the report; Parts 2 and 3 have their own executive summaries.