Research on Preparation of Lightweight Haydite by Using Sediment from Zhushan Bay of Taihu Lake

The main components, mineral composition and thermal property of the sediment from Zhushan Bay of Taihu Lake were analyzed, and the feasibility of producing lightweight haydite by the sediment investigated. The optimal production parameters were determined through single factor test of different time and temperature by using expansion rate and apparent density as assessment indicators. The microstructure and the leaching toxicity of heavy metals were analyzed by SEM and ICP-AES. The results showed that the main components of the sediment met the requirements of lightweight haydite basically. At the sintering temperature of 1 110-1 120℃ for 5-10 min and then cooling to ambient temperature, the lightweight haydite with good strength and apparent density of 0.8-0.9 g/cm³ could be produced without any other additive. During the process, not only was the solidification of heavy metal satisfactory but the leaching toxicity of heavy metal was very low.