The Impact Of Residual Flocculant On Flotation Performance Of Platinum Group Metal Ores

Abstract

The recycling of process water in the mineral processing plants is of paramount importance due to scarcity of fresh water. However, it has many challenges specifically on flotation performance. This research work focused on the impact of residual flocculant on flotation performance of Platinum group metal (PGMs) ores in terms of recovery. The impact of residual flocculant on PGMs recovery using recycled process water from a chrome processing rougher plant was investigated. Water samples from the flotation circuit and chrome plant were analysed for elemental composition, total dissolved solids (TDS), electrical conductivity (EC), pH, turbidity and total hardness. The effect of residual flocculant on settling was determined using settling test. The impact of high concentration of residual flocculant on PGMs ore in terms of recovery were investigated by comparing flotation circuit stream and chrome plant stream using Denver flotation cell. Results revealed that the chrome plant stream contained a higher concentration of ions compared to the was high flotation circuit stream. The chrome plant water had a pH of 8.41, TDS of 1331mg/l, EC of 217 mS/m, Turbidity of 2.42NTU and total hardness of 476 mg/l whilst the flotation circuit water had a pH of 7,73, EC of 87.3, TDS of 461, Turbidity of 1.025 NTU and total hardness of 224,7 mg/l. The recycled process water showed high settling rate compared to fresh water suggesting the existence of residual flocculant in the recycled process water. The flotation circuit pulp stream always showed higher recoveries of PGMs [70-78%] compared to CRD (54 -62%).