The Coaltech Research Association is working on 36 projects for the South African coal mining sector, following the local industry’s setbacks in the wake of the Covid-19 pandemic, which delayed various research projects, says Coaltech CEO Henk Lodewijks.

As a result, the association has decided to postpone its yearly colloquium to April next year.

“The projects are in different stages of completion, with the majority expected to be completed only next year. “Consequently, there are not enough projects suitable and ready for presentation at a colloquium this year,” he notes.

Coaltech has embarked on projects concerning various aspects in the coal mining industry, such as health and safety, dry processing and mitigating the damage on water resources and land caused by coal mining operations.

The association began working on a project in 2015 to rehabilitate a wetland damaged by acid mine drainage (AMD) from upstream mines and farmers whose activities changed the course of the spruit.

The association is testing the functionality of the spruit which, when effective, should improve water quality and mitigate AMD from coal mines.

“We are still doing studies on this wetland and Professor Paul Oberholster, from the University of the Free State, has been looking at the mechanisms active in the wetland that enable it to mitigate AMD and improve the water quality,” says Lodewijks.

Additionally, Coaltech is embarking on a project with the University of Cape Town (UCT) pertaining to the eutectic freeze crystallisation process, which aims to concentrate brines resulting from reverse osmosis treatment of saline effluent associated with coal mining. The project is at the laboratory stage, with UCT testing the relevant technology.

The institute has enlisted a commercial consultant to assist opencast mines with mine planning and rehabilitation planning.

This project aims to provide the mine with guidelines on the different bulking and settling factors for different materials such as sandstone, soil and coal. This will ensure that the rehabilitated landscape can fulfil its planned purpose.

Further, in collaboration with the Council for Scientific and Industrial Research, and the University of the Witwatersrand, Coaltech is analysing equipment at the Kloppersbos coal research facility, in Gauteng.

The research facility uses equipment to test the explosibility of coal dust; however, Lodewijks describes the equipment as being in a “state of disrepair”.

The project, therefore, aims to ensure that the equipment is refurbished and can deliver results that are comparable to international standards.

“This will be a significant feat, considering the original equipment was not designed to be comparable to equipment from countries such as the US and Australia,” he adds.

Other Projects

Coaltech is collaborating with the University of Pretoria regarding phytomining, whereby the university is establishing hydroponic towers by feeding plants in the tower with mine water and analysing what the plants can absorb from the water.

Lodewijks notes that tests have shown that the plants can absorb metals and rare-earth elements.

“It is interesting to see what the plants are collecting and how they are improving the water quality by being a potential mitigation strategy to address water pollution,” he enthuses.

Coaltech is also involved in a dry processing project with North West University to test the feasibility and viability of upgrading coal through winnowing.

Meanwhile, the association has embarked on a project looking at all aspects of the design and operation of refuge bays in order to ensure that they function optimally.

“Underground refuge bays are meant to provide miners with a safe environment in the case of an emergency, for instance, an underground fire. A recent event resulted in the question being asked how well refuge bays can sustain human life,” Lodewijks concludes.