In the mining business the cost of grinding media represents up to 40 per cent of the total milling cost and therefore grinding media optimisation has a direct impact on the concentrators’ bottom line. In the process of optimising grinding media alloys, Magotteaux developed its own methodology which consists of a series of analyses, tests, calculations and evaluations and assist the concentrator in optimising their processes.
This paper presents the Prominent Hill case study where this methodology has been applied on both the secondary ball mill and regrind IsaMill®.
The analysis of the wear conditions in the secondary ball mill allows Magotteaux to select a series of grinding media alloys to be tested to reduce grinding media consumption. By marking these different grinding media types with a unique drilling pattern, one can quantify the relative wear performance and cost effectiveness of each grinding media type within the same milling environment. After selecting the most economical grinding media composition a full scale industrial trial, involving topping up the selected grinding media is carried out and the media wear performance closely monitored and analysed.
For stirred grinding mills, suppliers propose different grinding media, mainly ceramic beads, with specific properties and cost. Therefore the concentrators’ choice is a compromise between grinding efficiency, wear resistance and cost. The selection of the correct grinding media for stirred milling and the assessment procedure will be presented in this paper. The test results of the new stirred grinding media type in the regrind IsaMill® at Prominent Hill are presented and analysed.
Weidenbach, M, Van Den Bosch, A, Bruwier, A, Ly,
T, De Bosscher, P and Philippe, C, 2012. Forging ahead – A collaboration between
the OZ Minerals Prominent Hill Concentrator and Magotteaux to improve plant
performance, in Proceedings 11th AusIMM Mill Operators’ Conference, pp 105-110 (The Australasian Institute of Mining and Metallurgy: Melbourne).