The viability of using the Witwatersrand gold mine tailings for brickmaking
M Malatse, S Ndlovu
The Witwatersrand Basin is the heart of South Africa’a gold mining
industry. The cluster of gold mines located in the Witwatersrand Basin
generates a significant amount of mine tailings, which have adverse effects
on the environment and ecological systems. In addition, disposal costs are
very high. The exponential population growth in the Witwatersrand area
has resulted in pressure on the reserves of traditional building materials.
Quarrying for natural construction material is very expensive and damages
the landscape. This work therefore examines the use of gold mine tailings
in the production of bricks.
Different mixing ratios of gold tailings, cement, and water were used.
The resulting bricks were then cured in three different environments – sun
dried, oven dried at 360°C, and cured in water for 24 hours. The bricks were
then tested for unconfined compressive strength, water absorption, and
weight loss. The results showed that the mixture with more cement than
tailings had a compressive strength of approximately 530 kN/m2. It was
also found that the best brick curing system was in a water environment.
Bricks made from tailings cost more than conventional bricks because of
the higher quantity of cement used, but the manufacturing process
consumes less water. Overall, the results indicated that gold mine tailings
have a high potential to substitute for the natural materials currently used
in brickmaking.
Keywords: gold mine tailings, construction materials, brickmaking.