The sulphate and neutralisation group of the water programme at the Council for Scientific and Industrial Research’s (CSIR) division of water, environment and forestry technology has been the fortunate receiver of Technology and Human Resources for Industry Programme (Thrip) funding for the past four to five years.
Thanks to this funding, the close collaboration with the implementation and commercial partners and the appointment of postgraduate students, the group can look back on a successful research period.
The main activities of the group revolve around the treatment of acid mine drainage (AMD), an acidic, usually sulphate- and metal-rich mine effluent. The water can be treated either chemically or biologically or using the CSIR-developed integrated system. This treatment system consists of: neutralisation, gypsum crystallisation, biological sulphate removal, and the biological sulphur and chemical CaCO3 production.
Implementation of the cost-effective limestone technology has occurred at Anglo Coal’s Navigation and Kromdraai mines, as well as at Ticor in Empangeni and BCL, a copper and nickel mine in Botswana.
Part of the treated water at BCL will be used to irrigate a citrus plantation, resulting in the creation of 400 jobs. The mine is planning to train and appoint fruit farmers from the neighbouring community, with the aim of enabling the potential farmers to start their own businesses.
Several postgraduate students have obtained further academic degrees, most of which have helped them further their careers at the CSIR. A MSc (Eng) student has been in control of the building and engineering operation at BCL, while a prospective PhD (Eng) student is the adviser at the limestone/lime plant at Ticor. Two engineering students have developed the ‘density meter”, which improves the quality of the limestone slurry for the dosing and handling system. Another two students are actively involved in the operation of novel reactor designs for the biological sulphate removal process, operating on hydrogen, thereby making the technology more cost-effective.