Identifying gold losses through application of SIMS technology

Mining companies are continuously searching for new technologies that can improve plant efficiency, by reducing operating costs and maximising metal recovery. Identification of how gold losses occur within an operating plant is crucial for determining appropriate operating strategies for improved metallurgical performance. Classical mineralogical and metallurgical techniques enable the operator to identify where losses occur in terms of particle size and mineral associations, however, how the gold is hosted within the mineral grains (for example, as solid solution or as fine microinclusions) is more difficult to determine. Secondary ion mass spectrometry (SIMS), a surface analytical technique is capable of detecting elements from ppm to ppb concentrations. Further, SIMS can be used to quantify gold in sulphide minerals, through comparison with implanted reference samples. Analysis of feed and tailing samples, from the processing circuit of the Kanowna Belle Gold Mine, in Western Australia using a combination of mineralogical, metallurgical and SIMS techniques was able to provide detailed information regarding the deportment of gold within this circuit. This analysis will be used to design and test process changes to improve gold recovery at a bench scale with possible implementation in the full scale plant. This paper provides details of the testwork methodology, and resultant laboratory study to improve gold recovery.