ZimPhos produces sulphuric acid from two plants, one plant uses local iron pyrites as a source of sulphur and the other uses imported elemental sulphur. The pyrites burning plant is maintenance intensive and was upgraded in 1988 to a capacity of 250 tonnes per day. About 85% of the acid produced is used for fertilizer production and the rest is used for aluminium sulphate production and sales, including exports mainly to the mining industry.