Abandoned Mine Tailings and Coal Ash Industrial Wastes for Sustainable Production of Geopolymer Brick Masonry: South African Case Study

Abstract

In various countries, a variety of waste by-products are disposed-off to the local environment, mostly due to lack of innovative initiatives for their utilisation. With human population growing strongly in most developing countries such as in Africa etc., lack of housing has become an endemic concern exacerbated by poverty and unaffordability of conventional construction products. Geopolymer technology provides new insights and possibilities into potential utilisation of a variety of mining and industrial waste by-products, currently being dumped in landfills leading to environmental pollution. This paper focusses on mining and industrial waste products that are currently not being utilised. In South Africa, mine tailings and bottom ash, also colloquially referred to “ash dumps”, exist in enormous quantities. Moreover, some of these waste products are presently an environmental menace responsible for discharge of acid mine drainage found in different geographical locations. The present study reviewed the potential utilization of mine tailings for brick making based on geopolymer technology. Also discussed are risks, hinderances and challenges to waste utilization including lack of public confidence attributed to radioactivity of some tailings-based brick products. While drawing from literatures worldwide, emphasis is placed on environmental and economic benefits of utilising these otherwise disregarded waste materials, to meet local societal needs of poor communities.