Perspective: Sustainable solution to the consequence of the mining industry recycling mining waste materials to lightweight green building materials

Australia is noted for its promotion to make the environment greener in order to improve sustainability. However, the reliance on mining export has been questionable in relation to environmental contaminants in Australia, due to the mining activities. Mining wastes, by-products of mining activities, possess the potential for environmental hazards. This is especially detrimental when no other disposal solution other than landfill is deemed viable to contain the waste materials. This is due to leaching of its heavy metal contents into the soil, resulting in potent contamination of agricultural soil as well as underground water. Sludge is one of the mining waste products. The historical handling method for its disposal is landfill or staging ground. Since the last decades, remediation of mining wastes has been enforced by legislation. That is to say, there has been no solution deemed sustainable as toxic chemicals including arsenic, mercury, chromium, and cadmium are all present in the waste, can contaminate both soil and drinking water. In the worst-case scenario, apart from soil contamination, there is the potential for human suffering through the shutting down of vital human organs and the central nervous system due to these contaminants being ingested. A recent technology, in converting marine clay into lightweight green building materials, has been proven as a prominent alternative use for contaminated soil. This study is to critically review the feasibility of using this technology to address the environmental landfill problems via converting the environmentally hazardous mining waste (sludge), to other waste materials to lightweight aggregates. These aggregate materials can further be utilized for various value-added green building applications, including lightweight partition wall, thermal insulative panel, and lightweight brick. This paper aims to evaluate, review, comment and provide perspective based on the previous research studies, accessing its viability and transferability as fundamental before carrying out the research activity.