Pasminco's Century Concentrator in North West Queensland commenced operations in November 1999. The nameplate production capacity of 500 000 tpa of zinc metal production in concentrate was achieved in August 2002. Completion of the production ramp up was successful due to the culmination of a number of initiatives throughout 2001 and 2002._x000D_
Mine to mill interaction to understand and eliminate head grade related bottlenecks affecting Concentrator production and reduce feed variation._x000D_
Grinding circuit process development - operating and process control strategies to improve stability and reduce grind size to support zinc recovery._x000D_
Pumping upgrades to control spillage in ultrafine zinc flotation Low density zinc flotation strategy - to improve silica-sphalerite separation to improve zinc recovery while maintaining acceptable silica in final concentrate._x000D_
Flotation circuit process development - froth crowders, froth cameras and reagent control strategies to improve primary zinc flotation performance._x000D_
Review and implementation of longer campaigns between planned shutdowns to improve availability._x000D_
Team reorganisation - to improve setting and implementation of metallurgical strategies._x000D_
This paper describes these initiatives and their contribution in achieving the production target. It also notes the ball mill motor failures that delayed the successful achievement of the ramp up, and Century's response to minimise the production impact. The paper also outlines the capital improvement program that was implemented to improve zinc recovery to design 82.5 per cent recovery once the production rate had been achieved.