Production of High Performance Haydite from Sewage Sludge
Using sewage sludge to manufacture green high performance haydite was investigated. Sewage sludge was blended with fly ash and river silt, made into raw haydite pellets and sintered. The haydite properties of different mix proportions and sinter parameters were studied. Then microstructure analysis and toxicity characteristic leaching procedure (TCLP) were performed. Results show that reducing sludge percentage of raw pellets decreases water absorption, also makes particle strength and apparent density raise. Increasing preheat temperature enhances particle strength and density while reduces water absorption. Sintered with optimum parameters, density grade of sludge haydite is 700, water absorption is 0.6%, and cylinder compressive strength is 6.6MPa. Microstructure analysis shows enamel surface and internal fine porous structure make haydite lightweight, high strength and low water absorption. And TCLP results show traces of heavy metal content are found in sludge haydite.
Zhenyu Du and X.B Sun
Z. W. Zhang et al., "Production of High Performance Haydite from Sewage Sludge", Advanced Materials Research, Vols. 113-116, pp. 1097-1100, 2010