污泥砖的研制及其影响因素研究

The development of sludge-brick and study on its influential factors

【目的】以城市污水处理厂干化污泥为掺料制备污泥砖,并对影响砖体性能的因素进行分析,为降低污水处理厂运行成本,消除污泥对环境的潜在危害提供理论依据。【方法】以粘土和污泥为原料制备污泥砖,研究不同污泥掺量、成型压力、烧结温度及保温时间下砖体抗压强度及吸水率的变化,以得出污泥砖制备的最佳条件。【结果】当污泥掺量为0~200 g/kg时,随着污泥掺量的增加,污泥砖的抗压强度明显降低,吸水率却随之增大;当成型压力为20~80 MPa时,污泥砖的抗压强度随着成型压力的增大先升高后降低,而吸水率则先减小后增大;当烧结温度为900~1 100℃时,随着烧结温度的升高,污泥砖的抗压强度逐渐增强,吸水率逐渐降低;当保温时间≥1.5 h时,随着保温时间的延长,污泥砖的抗压强度降低,吸水率逐渐增大。【结论】兼顾污泥砖性能与节能环保原则,制备污泥砖的最佳条件为：污泥掺量100 g/kg,成型压力控制60 MPa,烧结温度1 050℃,保温时间1.5 h。

【Objective】 Dried sludge of municipal wastewater treatment plant was taken as admixture to produce sludge bricks with low water absorption and high compression strength,in addition,several factors were analyzed influencing the property of bricks,which provided theoretical basis for reducing the operating costs of sewage treatment plants and eliminating potential hazards of sludge on the environment.【Method】 Sludge bricks were prepared with sludge and clay,the change of compressive strength and water absorption of which were studied under the conditions of different sludge contents,molding pressures,sintering temperatures and holding times so that we can obtain the optimum conditions of production of bricks.【Result】 When the sludge content was 0-200 g/kg,the compressive strength of bricks significantly reduced but water absorption increased with the increasing content of sludge;When the molding pressure was 20-80 MPa,the compressive strength of bricks increased first and then decreased while water absorption first increased and then decreased;When the sintering temperature was 900-1 100 ℃,compressive strength of bricks increased while water absorption decreased with increasing temperature;When the holding time was more than 1.5 h,the compressive strength decreased and water absorption increased accordingly with the time prolonging.【Conclusion】 Given consideration to both the property of mud bricks and the principle of energy saving and environment protecting,we found the optimized conditions of sludge-brick preparation：the sludge content 100 g/kg,molding pressure under 60 MPa,sintering temperature 1 050 ℃ and the holding time 1.5 h.