复合添加剂对垃圾焚烧飞灰熔融固化处理的影响

Effect of Compound Additive on Melting and Solidification of Fly Ash from Waste Incinerator

采用自行研发的特效复合添加剂对北方某城市生活垃圾焚烧厂产生的焚烧飞灰进行了熔融固化研究,主要考察了添加剂对熔融温度和重金属挥发的效果,同时探讨了熔渣中重金属的浸出毒性。实验运行结果表明,添加剂能使飞灰熔融温度从1320℃有效降低到1160℃;促进飞灰中某些重金属的挥发,当温度在1000℃时,不易挥发的重金属Cr、Zn的挥发率可分别增加24.1%和30.3%,而易挥发的重金属Pb、Cd挥发率可分别增加18.8%和20.0%,对于金属Cu,当温度在1350℃时,其挥发率可达93.5%,使残留在熔渣中的重金属大大减少,从而保证了熔渣中重金属的浸出满足有关标准。其添加剂添加量为5%(w/w),以空气为载气,进气流量250mL/min;熔融时间1h。

In order to test effect of the compound additive on temperature, heavy metal volatilization and toxicity of leaching heavy metals in slag, a melting and solidification process was carried out using own developed compound additive on fly ash from a northern city domestic waste incinerator. The results show that the additive can effectively decrease the melting temperature of fly ash from 1 320 ℃ to 1 160 ℃, and enhance the volatilization of some heavy metals in fly ash. When temperature was 1 000 ℃, the volatilization of Cr, Zn, Pb and Cd increased 24. 1%, 30. 3%, 18. 8% and 20% respectively. When temperature was 1 350 ℃, the volatilization of Cu was 93. 5%. And the content of heavy metals in slag was reduced greatly, then the leaching concentration of heavy metals in slag can meet the limit value prescribed by national standard. The operation parameters were that the proportion of compound additive was 5%, the flow rate of air which as carrier gas was 250 mL/min; melting time was one hour.