The recent advances of Raglan's comminution circuit
The Raglan Mine, part of the Glencore Group, is located in Northern Quebec and commenced production in 1997. The process plant was initially designed to process underground ores at 0.85 Mt/a. Throughout the years, Raglan has made modifications to the process plant such as converting the autogenous grinding (AG) mill to a semi-autogenous (SAG) mill that achieved the capacity of 1.3 Mt/a in 2008. In 2013, an expansion study was launched to develop new underground mines to expand the overall life of mine. New opportunities were identified in 2016 to debottleneck the milling circuit such as introducing a new Vertimill™ in tertiary grinding to ensure that the circuit could handle variable ore hardness at the new target throughput of 1.5 Mt/a. In late 2018, the new tertiary grinding circuit was commissioned, and production is now in line with the new desired throughput and final grind. In this paper, the authors discuss the modifications related to the comminution circuit expansion at Raglan and focus on the solutions considered and challenges encountered in the design, commissioning, and operation of this circuit.