Flotation data for the design of process plants Part 2 – case studies

Abstract

The Cadia Hill Gold Mine and the Hellyer copper, zinc and lead plant present different problems with widely different target grind sizes, liberation characteristics. The contrast is between Hellyer's sequential flotation circuit versus Cadia's ‘simple’ copper–gold flotation circuit. The common theme is that pyrite forms the principal floatable concentrate diluent. Hellyer ore contains finely disseminated chalcopyrite, sphalerite, galena and tetrahedrite. The flotation plant design was based on extensive benchscale test work (including locked cycle tests) on drill core and many months of operation of a 30 t h⁻¹ ‘pilot plant’ using the modified Cleveland Tin Mine processing plant. The Cadia concentrator was designed based on an extensive benchscale variability test work programme. Data from approximately a dozen locked cycle tests conducted on drill core and 2 weeks of continuous pilot plant trials of samples obtained from an adit into the orebody were used as the basis of design. The orebody is a low grade monzonite porphyry with disseminated chalcopyrite/bornite/pyrite (0·17%Cu, 0·73 g t⁻¹ Au). Methods used to establish the appropriated flotation circuits for the treatment of the Hellyer and Cadia ores, as well as the interpretation of the test work data for these particular operations, are discussed. The predicted versus actual operational plant is reviewed and the comparison was found to be satisfactory.