Gold miner Harmony Gold is implementing a R47-million bioenergy pilot-scale project involving the growing of bio crops, namely giant king grass and sugarbeet, on mine-impacted land and tailings in the Free State.
The project aims to simultaneously rehabilitate the impacted land in a bid to clean up the land and return it to an agricultural state.
Speaking at Harmony Gold’s fourth- quarter results presentation, held in Johannesburg earlier this month, CEO Graham Briggs said that, while renewable-energy applications in mining were not new, combining renewables with bioenergy and land rehabilitation was and that was what made this project unique.
The bio crops will be used as feedstock to generate natural gas. The natural gas will then be used as a substitute for fossil fuels in the company’s Harmony 1 metallurgical plant, where it will be burnt in place of polyfuel in the gold elution circuits.
As part of this process, Harmony Gold will also convert its electrical and polyfuel methods of heating the water needed in the elution process to biogas heating.
Phase 1 of the project aims to deliver 71 000 GJ within the first 18 months, with production being ramped up to 187 000 GJ within the first 36 months.
“This project aims to turn mine-impacted land to account by creating a value-added use for it and, in so doing, promote skills development and job creation for communi-ties and ensure a sustainable legacy in the Free State,” said Briggs.
One of the main benefits of this project, as noted by Briggs, is the reduction in the mine’s carbon footprint, which can, in turn, reduce carbon taxes that the mine may potentially incur.