Evaluation and Optimisation of The Grinding Circuit at Konkola Concentrator to Enhance Flotation Performance

Abstract

The grinding plant at Konkola concentrator accepts 18.5 tonnes per hour of crushed ore to produce a grind of 84% passing 75 µm. Although this grind and capacity were meeting the Konkola concentrator metallurgical requirements, the technical staff, however, sought for a more durable and lower down time equipment in the classification process of the grinding circuit in order to have an improved flotation performance and hence increase overall production. Prior to this work, the technical staff of the concentrator carried out a test work in order to optimise the efficiency of grinding plant ball mills fitted with a 38.10 cm, 45.75 cm and 50.80 cm Multotec hydro cyclone. The results of the test work showed that the 38.10 cm and the 45.75 cm hydro cyclones were unsuitable due to their low throughput and poor final product quality. The 50.80 cm Multotec hydro cyclone, on the other hand gave improved throughput and the required flotation product quality. Further investigations were done on the spigot, the throughput and the grind at which there was an enhanced flotation performance. The results revealed that the best flotation performance was at grinds above 83% passing 75µm. The spigot and the throughput were optimised at 100 mm and 20.59 tonnes per hour respectively