Use Of Oily Sludge As Alternative Raw Material For Cement Production By Co-Processing In Cement Kiln

This paper aims to investigate the feasibility of employing oily sludge as alternative raw material for Portland cement production by co-processing in cement kiln. The crystalline characteristics of calcined clinkers, the compressive strength and leaching toxicity of hydrated clinkers were determined. The results show that minerals and hydration properties of clinkers would not be transformed for the total content of heavy metals in clinkers is far below 0.1%. The leaching concentration of heavy metals in hydrated clinkers is relatively low, indicating that heavy metals could be absorbed into clinkers' structure through calcination and hydration reaction. The compressive strength of A is the highest after 28 d curing, which reaches about 21.84 MPa, 7.1% higher than that of ordinary Portland cement (OPC). This proves that the appropriate addition ratio of oily sludge as alternative raw material might be in the range of 2 similar to 5 wt.% of total raw materials due to its high content of P2O5.