污泥制陶粒技术可行性分析与烧结机理研究

研究了污泥烧结陶粒轻骨料的建材性能，分析了污泥制陶粒轻骨料的技术可行性和存在的难题，并从烧结过程的结构形态变化和晶体相反应机理角度讨论了可行的解决办法. 结果表明，当烧结温度为1　050 ℃，烧结时间为30 min时，烧结体的内部产生熔融液相导致烧结体收缩致密化，建材性能显著提高，但抗压强度仍达不到建材标准要求. 其主要原因是污泥中的有机物含量较高，烧结过程中有机物的挥发导致烧结体内部产生较大孔隙，使产品开裂. 污泥烧结体中的主要晶体相是石英、钙黄长石、钙镁磷酸盐和磷酸铝，污泥中磷的含量很高，因此，可添加高铝无机材料促进钙镁磷酸盐和磷酸铝高强晶体相的形成，提高烧结体抗压强度，经调质后利用污泥烧结陶粒轻骨料技术可行. 

Sintering Characteristics and Application Research of Sewage Sludge in Producing Lightweight Aggregate

This article investigates the feasibility of using sewage sludge to manufacture haydite, analyzes the related problems, and discusses the resolutions by studying SEM microstructures and crystal reactions. The results show that, when the sintering temperature lasted 30 min at 1　050　℃, the specimen beganto melt and the construction characteristics were improved significantly; however, the compressive strength could not meet the standard of construction materials. This was because much organic substance in the sewage sludge volatilized when sintering, which resulted in large pores in the sintered sample and product cracking. Quartz (SiO₂), gehlenite (2CaO·Al₂O₃·SiO₂), calcium magnesium phosphate(7CaO·2MgO·3P₂O₅) and aluminum phosphate (AlPO₄) were generated in thesintered products.Due to high phosphate in the sewage sludge, it was feasible to increase the formation of solid crystals of calcium magnesium phosphate and aluminum phosphate by adding inorganic materials containing high aluminum to the sewage sludge; thisincreased the compressive strength of the sintered products. This result indicates that it was feasible to produce lightweight haydite by sintering sewage sludge.