Quantifying variability of ore breakage by impact: Implications for SAGmill performance

Farhad Faramarzi*, Vladimir Jokovic, Robert Morrison, Sarma S Kanchibotla 

Comminution '18, 22-25 January 2018, Ottawa, Canada

ABSTRACT 

The standard JK drop weight test breaks single particles at five size fractions at different energy levels by dropping a given weight from a certain height. The progenies of all particles at a given energy level are sieved and the degree of breakage of all those particles at that energy level is presented as t10 (percent passing 1/10th of original size). This method assumes that all of the particles in a single size fraction have the same mass and similar degree of breakage and calculates the average breakage characteristics of an ore domain from impact loading. Hence, this standard approach does not capture the breakage variability within an ore domain. To investigate the breakage variability of ore, the drop weight testing method has been extended where the energy applied and the degree of breakage for each particle within the sample is measured separately. Therefore, the degree of breakage for the ore domain is expressed as an envelope of t10 vs energy curves. This approach provides some insight into the intrinsic variability within an ore domain from impact loading. Four rock types were tested by the extended testing method and the implications of ore breakage variability for a SAG mill treating these rock types are simulated for a standard SAB circuit using the JKMRC grinding models. 

AUTHORS

Farhad Faramarzi*, Vladimir Jokovic, Robert Morrison, Sarma S Kanchibotla 

Julius Kruttschnitt Mineral Research Centre, Sustainable Minerals Institute, The University of Queensland, Indooroopilly, Australia 

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

ACKNOWLEDGMENTS

CEEC acknowledges and thanks Mineral Engineering International (MEI) for organising the Comminution ’18 conference.

The conference proceedings USB is available for £95 by emailing This email address is being protected from spambots. You need JavaScript enabled to view it.. Selected papers from the conference were published in a virtual special Comminution issue of Minerals Engineering journal.