Monthly Monitoring of Metallurgical Performance at the Kidd Concentrator using QEMSCAN and the Link to Ag Recovery to Cu Concentrate

摘要

The Kidd concentrator and Kidd mine are located in Timmins Ontario Canada. The Kidd Mine is one of the world's largest massive sulphide deposits. XPS - Expert Process Solutions has worked with Kidd concentrator monitoring performance based on monthly composites during 2015-2017. Using automated mineralogy (QEMSCAN, LA-ICP-MS) on sized samples of Flotation feed, Cu Concentrate, Cu Tailings/Zn Feed, Zn concentrate and Zn tailings, mineralogical drivers of flotation performance were examined. It has been observed historically that Ag recovery is variable and that better Ag recovery to Cu concentrate is obtained with higher Zn losses to the Cu concentrate. The Cu circuit performance is driven by both Zn head grade and Fe sulphide content (including the ratio of pyrite to pyrrhotite) of the feed. Response of the Cu circuit to higher sulphide content feeds is to slow flotation and shift up or down the Cu/Zn and Cu/Fe sulphide selectivity curve to control concentrate grade, which in turn increases losses of slower floating coarse chalcopyrite. This slowing of the Cu circuit was also impacting Ag recovery, reducing the recovery of liberated Ag minerals to the Cu concentrate. The addition of the collector 3418A to the Cu circuit improved flotation kinetics of the liberated Ag minerals for similar high sulphide feed compositions. Zn circuit performance is consistent on a unit operation basis with recovery reaching 93-96% of the theoretically determined recovery from Zn circuit feed mineralogy.