These papers are preprints of accepted manuscripts currently undergoing the editing process. Please feel free to cite them as published preprints. The preprint version of the paper will be replaced by the copy edited, typeset and proofread version as soon as it is available, and associated with the same digital object identifier (DOI).

Using discrete element method to investigate ball milling power draw, load behaviour and impact energy profile under various milling conditions

M. B. Kime

ABSTRACT Discrete element method (DEM) modelling has proven over many years to be a powerful tool for studying particulate systems within the mineral processing industry. DEM simulations were conducted to investigate the power draw, load behaviour and impact energy profile of an experimental ball mill under different milling conditions. The variables considered were mill rotational speed (% critical speed), ball size, and lifter face angle. The DEM simulation results indicated that the grinding efficiency would be enhanced by use of 80% critical speed, 30 mm ball diameter, and 45° lifter face angle. These findings can be useful in guiding actual ball milling tests involving an ore sample.

Operating experience and developments of G-REX and AURIX100 resin exchange technology

P. Richards, A. Lewis-Gray, and N. Katsikaros; M. Davies

ABSTRACT To optimize the recovery of gold in complex leach-to-electrowinning processes, Gekko Systems developed the Gekko Resin Exchange Column (G-REX) as an intermediate step, using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin. Operational experience has been gained at the CGT Ballarat Gold Plant in near continuous operation since 2008, treating unclarified concentrate leach solution. The extension of the technology to higher throughputs and more complex chemistry is discussed.


P. F. Wells, P. Langlois, J. J. Barrett, J. Holmes, M. Xu, and G. Labonté

ABSTRACT The Voisey’s Bay mill processes a high pentlandite and chalcopyrite ore in a largely pyrrhotite/troilite matrix. During 1994–1997, circuit development focused on making a relatively low-grade nickel concentrate. When flowsheet development resumed in 2001, the target grade was raised from 14 to 20% Ni. Initially triethylene tetramine and sulphite pyrrhotite depressants were used in a lime circuit, but by recycling process water and the contained thiosalts—the required nickel grade was made without depressants. Construction and commissioning of the mill were fast-tracked, with start-up in September 2005. Ramp-up of throughput and metallurgy was faster than any other recent nickel installation. Tonnage was limited mainly by concentrate dewatering due to higher than expected ore grades.


C. Bolduc and J. Cayouette, AgnicoEagle Mines Rouyn-Noranda, Québec, Canada; P. Blatter, GreenStone Gold Mines, Toronto, Ontario, Canada

ABSTRACT The LaRONDE mill in the Abitibi region of Quebec was commissioned in 1988 and has been treating the LaRONDE ore since 2000. The mill has experienced many expansions to accommodate 7,500 tonnes/day (t/d) and recently ramp down to 6,000 t/d since the deep extension began. The process was designed to recover gold, silver and base metals. In 2008, the Goldex plant in the Abitibi region began trucking gold-pyrite concentrate (TCGO) for gold extraction at a treatment plant feeding its pulp to the LaRONDE mill, increasing gold output by 40,000 ounces. In 2009, the high gold grade Lapa ore processing facilities were annexed to the LaRONDE plant, increasing output by 120,000 ounces of gold. This paper outlines the metallurgical highlights, challenges, and future outlook related to the treatment of different ore types.