Christopher J. Greet, John Twomey and Allen Chung
43rd Annual Meeting of the Canadian Mineral Processors, 18-20 January 2011, Ottawa, Canada
It is widely accepted that the type of grinding media has an impact on the grinding chemistry and subsequent flotation behaviour of the sulphide minerals being separated. There are countless laboratory investigations demonstrating that inert grinding media produces more oxidising pulp potentials, reduced levels of grinding media corrosion products and superior concentrate grades and valuable metal recoveries. However, taking these results to industrial scale has proven difficult.
Work conducted at the Ernest Henry Mine, in north western Queensland, Australia, at laboratory and pilot plant scale, clearly indicated that using a high chrome grinding media resulted in significant improvements in both copper and gold recoveries. However, advancing this work to plant trial represented considerable financial and technical risk to the mine.
This paper provides details of the protocol developed and used during the high chrome grinding media plant trial. It describes the test regime employed to measure changes in pulp chemistry, and the statistical methodology utilised to interpret the results. The work also highlighted the need for close cooperation between the metallurgists on site and the researchers conducting the trial.
To date, the trial has produced excellent results: indicating that the copper recovery has improved by about 2%. The successful application of high chrome grinding media to the Ernest Henry ore has increased metal value by USD18.7 million per annum based on current spot price for copper.
Christopher J. Greet (1), John Twomey (2), Allen Chung (3)
CEEC acknowledges and thanks CIM’s Canadian Mineral Processors for organising the 43rd Annual Meeting. Proceedings can be purchased from https://www.cmpsoc.ca/publications/