造纸污泥添加剂对麦秆灰烧结熔融特性的影响

利用灰熔点测试仪、XRD及XRF等仪器,对比研究了造纸污泥(脱墨污泥、造纸废水污泥)、城市废水污泥作为添加剂对麦秆灰熔融特性的影响,考察了烧结和熔融过程中的组分变化,分析了污泥添加剂对麦秆灰的作用机理;进一步将污泥添加剂与常规添加剂进行灰熔融特性对比研究。研究发现,添加比例控制为3%-10%,造纸污泥(脱墨污泥、造纸废水污泥)软化温度提升效果均优于城市废水污泥;在添加比例控制为5%时,造纸废水污泥对麦秆灰软化温度提升效果最好;增大添加比例过程中,造纸废水污泥Al_2O_3修饰骨架作用明显,但灰中长石类物质逐渐增多使得软化温度提升效果下降;在不同温度下,脱墨污泥主要是通过形成硅铝榴石使得灰熔点提升,造纸废水污泥则主要是通过生成高熔点物质CaSiO_3抑制低熔点硅酸盐形成,城市废水污泥升温中存在明显SiO_2晶态转变过程;使用污泥添加剂作为抗结渣添加剂具有良好应用前景。

Effects of paper mill residual additives on sintering and melting characteristic of wheat straw

The effects of paper mill residues (delinking sludge, paper mill sludge, municipal sewage sludge) addition on slagging tendency of wheat straw were investigated using ash melting point test system, X-ray fluorescence (XRF) and powder X-ray diffraction (XRD). The differences between other 4 common additives were also discussed. The results show that addition of delinking sludge and paper mill sludge behaves better than municipal sewage sludge in blending range of 3% to 10%, while softening temperature of wheat ash tends to get the highest value when adding 5% paper mill sludge. Along with the blends increasing, Al₂O₃ plays an important framework structure modification role while adding paper mill sludge. While generation of feldspar such as orthoclase and anorthite takes place, the softening temperature decreases. In addition, silicon aluminum garnet is more likely to form to enhance the fusion characteristic temperate while adding delinking sludge. On the contrary, formation of high melting point material(CaSiO₃)inhibits low melting silicate by adding paper mill sludge. Components analyses indicate that crystal structure of SiO₂ is changed along with municipal sludge added. Sludge used as anti-slagging additives is promising.