城市污泥对固废陶粒的强度影响研究

Study on the effect of municipal sludge on the strength of solid waste ceramsite

以城市污泥、建筑弃土等固废烧制陶粒,利用XRD、MIP孔结构和SEM等测试手段研究城市污泥对陶粒强度影响。结果表明:通过正交试验获得较优的烧结制度,烧制出污泥掺量为20%的轻质高强陶粒;污泥掺量及对应陶粒氧化物含量(SiO_(2)及Al_(2)O_(3))均影响陶粒强度;陶粒内部结构随着污泥掺量的增加而变得疏松,污泥掺量为20%的陶粒较掺量为5%的陶粒孔隙率大3.9%以上,陶粒孔径也随着污泥掺量的增加而增大,进而影响陶粒强度;对于氧化物,Al_(2)O_(3)含量是影响陶粒强度的主要因素,当其含量超过20.5%以后,陶粒主晶相由石英相逐渐转变为蓝晶石,对陶粒强度提升明显。

The ceramsite was prepared with solid wastes such as urban sludge and building spoil,and the test methods such as XRD,MIP pore structure and SEM were used to study the influence of urban sludge on the strength of ceramsite.The results show that an excellent sintering system was obtained through orthogonal experiments,and light and high-strength ceramsite with a sludge content of 20%was prepared.The amount of sludge and the corresponding ceramsite oxide content(SiO_(2) and Al_(2)O_(3))affect the strength of the ceramsite.The internal structure of ceramsite becomes loose with the increase of sludge content.The ceramsite with 20%sludge content was more than 3.9%more porous than the ceramsite with 5%sludge content.Therefore,the strength of ceramsite decreases with the increase of sludge content.For oxides,Al_(2)O_(3) content is the main factor affecting the strength of ceramsite.When the Al_(2)O_(3) content exceeds 20.5%,the main crystalline phase of ceramsite gradually changes from quartz phase to kyanite,which obviously improves the strength of ceramsite.