In this paper, the application of wastes as raw materials to cementitious mineral was investigated. A rolling slag, which contains plenty of heavy metals, was used as a raw material to synthesize calcium sulfoaluminate. It was found that the suitable burning temperature of CSA clinker is between 1,250°C and 1,300°C, and the residual content of heavy metals in the CSA clinker turned out sequentially as Cu, Zn, Cr, and Pb. According to the results of the investigation, it is believed that a large amount of the Cu, Zn and Cr present in the raw materials were fixed in the CSA clinker formed during the sintering process. It was further found that the distortion of the crystal morphology of hydrate, which was ettringite, took place according to the substitution of heavy metals during the hydration process.