Increasing the Recovery of Fine Sphalerite at Kidd Creek Mines, Falconbridge Limited, Canada

摘要

The flotation and surface properties of fine sphalerite particles were investigated at Kidd Creek Mines in order to prevent their misreporting to final tailings. Plant surveys performed on the zinc circuit showed the total loss of zinc to the final tailings was 7.8%. Size-by-size analysis indicated that the most significant proportion of this loss was as liberated <10 micron sphalerite particles. Their contribution was 2.5% and equates to approximately one-third of the total sphalerite lost. The low flotation rate exhibited by these particles was attributed to their surface properties. ToF-SIMS analysis identified higher surface oxidation and lower exposure of copper as the reasons for the loss of sphalerite. Flotation experiments on scavenger feed pulp showed that the addition of standard reagents used in the zinc circuit almost doubled sphalerite recovery in the scavenger bank. Circuit simulations of increased scavenger unit recoveries for both sphalerite and gangue particles by similar proportions (derived from batch laboratory experiments) showed a 4% feasible increase in zinc recovery to final concentrate with a marginal decrease in zinc grade.