Diversified miner Exxaro has unveiled the first of three water treatment plants designed to mitigate underground water storage constraints, protect scarce natural water resources and ensure the safety of mineworkers.

The launch of the R250-million Robert Clarke Water Treatment Plant (WTP) at the underground Matla coal mine, near Kriel, in Mpumalanga, is the start of Exxaro’s holistic groupwide water management strategy, says Exxaro coal financial performance group manager Mellis Walker.

The WTP will treat 10 Mℓ/d of water pumped from the operation’s mined-out underground workings, with 2.5 Mℓ of the recycled water to be reused as potable water by the mine and the surrounding communities and the remaining 7.5 Mℓ discharged into the nearby Olifants river for downstream use.

The coal mining operations, which produce between 10-million and 11-million tons of coal a year and provide 12% of coal used by State-owned power utility Eskom, currently experience significant water ingress that heightens flooding risks, which threatens the safety of mineworkers and increases the potential risk of environmental contamination.

Most Viable

With a few underground dams and one above-ground dam servicing the Matla 1, 2 and 3 mines at capacity, the construction of a WTP has emerged as the most viable and sustainable option for disposing of excess water from its mining operations.

According to Matla business unit manager Danie Stapelberg, the mine would have faced a stoppage by mid-June, owing to water storage constraints.

At the start of 2014, Exxaro-appointed Prentec, which will manage the plant for the next two years, broke ground on the plant that would purify water and prevent the release of contaminated water into the environment.

The modular plant will be fully operational by the end of May, with the water pumping prioritised in the regions earmarked for mining in the next five years.

Walker explains that the construction and commissioning of the plant form the first part of the group’s water conservation plans.

A pilot plant is currently in operation at Exxaro’s North Block Complex operation, near Belfast, and, with a capital budget approved, a full-scale WTP will be implemented by the end of this year.

The group has also completed a prefeasibility study and started a bankable feasibility study at the Arnot mine, near Middelburg, where Exxaro aims to establish another WTP by 2017.