Andani Mphinyani Andani Mphinyani

Project Title: South African coal waste re-purposing as alternative for topsoil production in rehabilitation of mined areas.

Research Theme: Value from Waste

Supervisor(s): Juarez Amaral Filho, Sue Harrison

Abstract

The rehabilitation of mined areas requires a significant amount of topsoil. The shortage of topsoil is one challenge faced by the mining industry due to the need for transporting soil from “borrow pits” with the well know economic liabilities and environmental footprint. Coal processing activities generate tons of wastes that are disposed of either in dump deposits or tailing dams. Repurposing part or even the total mass of those wastes both removes waste and reduces the need to mine or burrow topsoil, thereby protecting over-exploitation of the natural capital. However, the fundamentals of a fertile soil and the soil-plant relations must be understood, in this case, the project seeks to identify a suitable grass species for fabricated soils to achieve sustainability and ensure ecological functionality in a short period of time. In this work, ultrafine coal waste will be amended with organic and nutrient sources; if required an alkaline source will be used, in order to produce topsoil of a soil-like physical structure which will provide a growth medium with capacity to maintain a long-term functional topsoil as an alternative for mine rehabilitation taking into account local guidelines.