Abstract:A foreign enterprise adopts a whole wet process to produce electro deposited copper supporting sulfuric acid making based on sulphur for self use. Ore oxidation rate dropped dramatically due to ore property changes. A roasting system is built to deal with sulfide ore, but roasting gas cannot be directly incorporated into the existing system. The original sulfuric acid making system must be transformed to make full use of existing facilities, save investment and ensure up-to-standard discharge of flue gas.