水洗城市生活垃圾焚烧飞灰作为水泥混合材的试验研究

Study on utilizing washing pre-treated MSWI fly ash as cement admixture

针对水洗城市生活垃圾焚烧飞灰(PW-MSWI)的组成和特性,在实验室进行了PW-MSWI作为水泥混合材的试验研究。研究表明,PW-MSWI中SO3和Cl-含量较低,并具有一定的胶凝活性,可作为水泥混合材使用;综合水泥力学性能和粉磨能耗分析,得出宜采用单独粉磨后混合的工艺将PW-MSWI用作水泥混合材,且粉磨到比表面积562m2/kg左右为最佳;掺加PW-MSWI后,混合水泥的标准稠度用水量增大,凝结时间变化不明显,对水泥的体积安定性无不良影响;PW-MSWI与粉煤灰和矿渣粉复掺有助于提高水泥的早期强度;混合水泥中的重金属浸出毒性低于浸出毒性标准限值,环境安全性良好。

Study on utilizing washing pre-treated MSWI （PW-MSWI）fly ash as cement admixture were done in laboratory based on the components and characteristics of PW-MSWI fly ash. The results indicated that the PW-MSWI fly ash could be used as cement admixture, for its low SO3 and Cl- content and certain cementitious activity. Regard on both of cement properties and grinding energy consumption, the optimum grinding method was that separately grind the PW-MSWI and other materials then mix them, with the best specific surface area was around 562m2/kg. After the addition of PW-MSWI fly ash, the water requirement of normal consistency would be increased, the setting time of the cement did not change significantly. The PW-MSWI fly ash had no negative effect on the soundness of blended cement. The early strength of cement could be increased by the addition of PW-MSWI fly ash, fly ash and GGBS compositely. The leaching concentration of heavy metal from blended cement was lower than leaching toxicity limited value, the environmental safety of this blended cement could be acceptable.