Research on the Resource Utilization of the Sewage Sludge in Silicate Industry

摘要

With modulus (KH = 0.89, SM = 2.42, IM = 1.70), substituting the sludge for the shale in the calculation of the cement burden, we studied the influence of different amount of sludge on the cement raw meal sintering, mineral composition, compression strength and the leaching value of heavy metal element. The result indicates that as the proportion of the sludge increased, the free calcium oxide reduced first and increased later, while the compression strength increased first and then reduced. When the proportion of the sludge was 2.56%, the amount of the free calcium oxide in clinker was lowest, and the 28day-compression strength reached the maximum which was 137 times as large as the cement clinker without sludge. The XRD and SEM test results also show that the composition of clinker and mineral structure remains unchanged when shale replaced by sludge. When the sludge proportion is 12.18%, free calcium oxide and compression strength are nearly the same as the cement clinker without sludge, and leaching value of heavy metals could satisfy the concentration limits of hazard constituent in the lixivium.