Xikuangshan (or Hsikwangshan) is known as Antimony City because the company’s capacity to produce antimony and downstream products is the largest in the world. Construction of the zinc smelting plant commenced in 1996 as a business diversification, the initial vertical retort capacity being 15kt/a. By installing a second roasting and sulphuric acid stream and by doubling the number of retorts and distillation columns, the capacity of the smelter was increased to 35kt/a slab zinc in 2001. During 2012, in order to avoid inter-company competition with Zhuzhou, Xikuangshan moved to produce high purity zinc by the installation of a vacuum distillation column. With this move, the total capacity of the smelter decreased to 20kt/a made up of 15kt/a high purity zinc capacity and 5kt/a normal refined zinc capacity.