Zinc smelting started in 2005 with a capacity of 80kt/a. Expansion of the smelter to 200kt/a was commissioned in 2009. Further expansion of the smelter to raise the capacity to 300kt/a started in 2010. This was expected to commission during late 2011/early 2012 however in January 2012 a cadmium pollution incident occurred in Hechi city. This forced construction to stop; and combined with weak market conditions meant that the expansion did not finally commission until December 2012.