Production of Sludge Ceramsite from Sewage Sludge, Municipal Solid Waste Incineration Fly Ash and Clay

The few reuses and large stockpile of sewage sludge led to a series of social and environmental problems. This study investigated the possibility of using the sewage sludge and municipal solid waste incineration (MSWI) fly ash as materials to prepare ceramsite by a high temperature sintering process. Two experiments were designed to investigate the addition of sewage sludge and MSWI and sintering treatment. The result showed that the mass ratio of sewage sludge to MSWI fly ash was 8:2 and the the pellets, sintered at 1080°C for 8 min, were beneficial to produce sludge ceramsite. Property tests of sludge ceramsite showed that sludge ceramsite was light (with an apparent density of 680kg/m³), waterproof (with a water absorption of 6.7%), hard (with a compressive strength of 5.4Mpa) and nontoxic (contents of toxic metal leaching test were found to be within the limits of China's regulatory requirement). These results reveal the feasibility of recycling sewage sludge and MSWI fly ash by sintering as a construction material.