添加剂对垃圾焚烧炉飞灰熔融特性的影响

Influence of Additives on Melting Characteristics of Fly Ashes From Municipal Solid Waste Incinerator

将SiO2、CaO和Al2O3按不同比例与垃圾焚烧炉飞灰均匀混合,对混合后试样的熔融特性进行实验研究。结果表明:当添加剂加入量在15%左右时,试样的灼烧减量基本趋于稳定,添加量过高或过低试样灼烧减量波动均很大。适量(15%左右)的加入3种添加剂时,SiO2可使试样达到更好的熔融效果,CaO不利于试样的熔融,Al2O3可提高试样的硬度和致密性。添加剂对熔融试样的重金属分布有显著影响,添加SiO2、CaO均能促使Cr、Ni固溶在熔融体中,且SiO2含量增加有助于As的挥发;而CaO可抑制As挥发。Al2O3除对Ni固溶有正面影响外,对Cr、As、Cu的固溶有负面影响。

Mixed ash samples of fly ashes from MSW incinerator, which adding additives of SiO_2, CaO and Al_2O_3 in different rations, were carried out to determine melting characteristics. The results showed that the rates of ignited loss measured different samples were stable with the addition of additives about 15 wt %. The ignition loss of melted samples was investigated. With changes of amounts of additives, the ignition loss significantly fluctuated. It was found that the better melting effect of samples facilitated by adding appropriate SiO_2 additive. Adding CaO additive was disadvantaged for propelling the melting reaction. Adding Al_2O_3 was much effective for improving the hardness and tightness of samples. Additives in fly ashes had remarkable influence on heavy metals distribution in melted samples. The residue rate of Cr and Ni in melted samples would increase adding SiO_2 and CaO. The augment with the content of SiO_2 was beneficial to enhancing evaporation portion of As. The existence of Al_2O_3 hindered residue fraction in sample of Cr, As and Cu with exception of Ni.