The industrial research on the co-disposal of municipal sludge using new dry process cement kiln

Co-disposal of sewage sludge in cement kiln is an economic and feasible method of resource utilization. The industrial test of co-disposal sludge was carried out in Beijing Taihangqianjing cement limited company. The semi drying sludge as a raw material was transported to the decomposition furnace for combustion by bucket elevator. The physical properties and mineral composition of the cement clinkers produced with and without sludge were compared and analyzed. The result showed that the chemical composition and properties of the clinker were similar to the untreated sludge in the process of co-disposal sludge by cement kiln. There was no obvious change in the specific surface and setting time whether co-disposal sludge or not (p>0.05). The fineness of clinker was reduced when co-disposal sludge to a certain extent, and the standard consistency water demand ratio was slightly lower. The 28d compressive strength and breaking strength were increased evidently. It can be seen that the dry sludge as a substitute for cement kiln is feasible.