Re-purposing of tailings from a sulphidic based ore : an extra source of soil filler material or an additional source of acidity

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: The mine of Spektakel, situated in the Northern Cape of South Africa, is an old copper mine with a long history of owners. This turbid history has led to the mismanagement of the site which has resulted in the generation of AMD. Recently the mine has restarted operations and has begun re-processing some of the old tailings materials found on the site in hopes of extracting further copper. To do this the mine constructed leach pads and leach ponds to facilitate the process. In doing so, the mine looked to re-purpose some tailings material that was determined to have too little copper for extraction. The re-purposed tailings material was then used as extra soil material to help construct service features for the new operation such as roads and berms. Detailed analyses of the soils on the mine site were completed to determine whether the practice of re-purposing tailings material, although deemed to have too little copper for re-processing, would pose as an additional source of AMD. Soil samples from the surface, 5 cm and 30 cm were collected from a total of 17 samples locations. The range of analyses included testing the soils pH, EC, examining their elemental composition and mineralogy as well as conducting an acid-base accounting test. It was also discovered that there was a substantial amount of water soluble material present which was then examined further by completing a sequential leach extraction. From these analyses it was determined that the soils contained a high amount of leachable S, Mg and Cu. The semi-arid climate of the region has resulted in the precipitation of secondary soluble minerals at the surface, which are susceptible to dissolution and migration during heavy rain events.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar
Description
Thesis (MSc)--Stellenbosch University, 2021.
Keywords
Mines and mineral resources -- South Africa -- Northern Cape, Acid mine drainage, Tailings (Metallurgy), Soil filler material, Copper ores -- South Africa -- Namaqualand, Mineral industries -- Waste disposal, UCTD
Citation