Copper slag differs by chemical composition and structure, depending on the type of processing. Copper slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and type of furnace used. The aim is to produce a typical foundry pig iron with the chemical composition of C > 3.40 wt.%, Si 1.40 to 1.80 wt.%, Mn 0.30 to 0.90 wt.%, P < 0.03 wt.% and S < 0.03 wt.% from copper slag. But foundry pig iron manufactured from copper slag contains a high sulphur content. Therefore, this study examines how to conduct desulphurization. Desulphurization roasting and reduction smelting with desulphurization additives used to remove sulphur from the copper slag. The results showed that desulphurization effect of desulphurization roasting is poor but when combined with reduction smelting with CaO addition is possible to manufacture low sulphur pig iron from copper smelting slag.