Quantification of water usage at a South African platinum processing plant
The mining industry utilises 3% of the total water withdrawn in South Africa and is one of the industries responsible for the deterioration of water quality in South Africa. Mine water requirements can be reduced with correct implementation and/or improvement of current mine water management strategies. Any reduction in mine water requirements will reduce the demand on current water resources and hence the impact on water quality. The direct water footprint for 2 concentrators, a smelter and a tailings dam of a platinum processing plant were calculated using the Water Footprint Network assessment method. This includes the sum of the blue-, green- and grey-water footprints. Water footprints of chemicals used during flotation were excluded from the scope of the investigation. Water used in change houses and offices was included. The water footprint calculated from June 2012 until May 2013 was 201 m3/kg PGM (platinum group metals). The first concentrator had a water footprint of 76 m3/kg PGM, while the second had a water footprint of 110 m3/kg PGM. Overall, the total grey-water footprint made the largest contribution, accounting for 73%, the blue-water footprint was the second largest (27%), and there was no green-water footprint.
Keywords: Water in mining, blue water, green water, grey-water, footprinting