垃圾焚烧飞灰成型及低温烧结稳定化研究

对焚烧飞灰进行水泥固化成型,并对成型体进行烧结研究。通过XRD、SEM等表征方法探索垃圾了焚烧飞灰在高温条件下的反应机理,以及添加助熔剂对烧结的影响。结果表明:添加Na2CO3可促进水泥早期的固化,但对水泥后期的固化不利;在养护时间为2 d时,水泥固化飞灰试块抗压强度达到1.91 MPa,完全满足成型的要求;XRD和SEM分析结果表明:固化体烧结后主要生成钙铝黄长石、硅酸钙等,Na2B4O7·10H2O的助熔效果明显;随着烧结温度的升高,重金属Ni、Cu、Pb和Cd的浸出浓度和浸出率下降,随着助熔剂Na2B4O7·10H2O添加量的增加,重金属Cu和Cd的浸出率增加,Pb的浸出率降低;浸出实验结果表明:重金属Ni、Cu、Pb和Cd的浸出浓度远低于国家标准。

THE MOLDING AND LOW TEMPERATURE SINTERING RESEARCH FOR STABILIZATION OF MSW FLY ASH

Cement molding and sintering of MSW fly ash were carried out，and XＲD/SEM were applied to seek the sinteringmechanism and the effect of fluxing agent． The results showed that Na2CO3 could accelerate fly ash solidification during theearly phase of cement molding，but showed negative influence with the solidification time increased; With a curing time of 2 d，the compressive strength of cement solidified body reached 1. 91 MPa，completely meeting the intensity requirements of makingbad body; XＲD and SEM analysis results showed that the solidified body mainly produced gehlenite and calcium silicate duringsintering，and Na2B4O7·10H2O had obvious fusion effect; The leaching concentrations of Ni，Cu，Pb and Cd reduced withsintering temperature increased，and leaching concentration of Cu and Cd increased with dosage of Na2B4O7·10H2Oincreased，but Pb decreased． The leaching experiment results showed that the leaching content of Ni，Cu，Pb and Cd werelower than the national standard limit．