South Africa: Waster water specialist Talbot is working with a coal producer in the Highveld region to remove gypsum generated as a by-product of its mine water purification process.
As part of a pilot project conducted in March 2020, a hydraulic filter press was used to dewater the solids, dry and press them into briquette form for transportation to end-use customers. The remaining filtrate was directed to an evaporation dam before returning to site processes via a blend line. Talbot says it reduced the waste solids from 84 - 2900mg/l and demonstrated that the technology would extract gypsum at a rate of 100kg/hr on a full-scale site operation. Previously the company has used this method on behalf of a South African platinum producer where the recovery of precious metals from a wastewater stream using the same technology.