【作者】 陈伟；

【导师】 张以河；

【作者基本信息】 中国地质大学（北京） ， 化学， 2010， 硕士

【摘要】 赤泥是氧化铝生产过程中产生的工业废弃物,我国赤泥年产量可达数千万吨。赤泥的堆放已造成严重的环境问题,因此如何合理利用赤泥是一个具有重要价值的课题。赤泥具有化学成分相对稳定、颗粒细、比表面积大以及在高温条件下可以烧结等特点,这决定了其具有一系列的应用价值。本论文利用赤泥、粉煤灰等价格低廉的废弃物为原料,采用造孔剂法和有机泡沫浸渍法两种造孔工艺制备了赤泥多孔材料。实验发现,在满足强度要求的前提下,在烧结温度为1200℃时可以制得综合性能较好的多孔材料,赤泥、粉煤灰和膨润土等三种原料的合理比例为10:5:4。不同的工艺和不同的造孔剂可以控制赤泥多孔材料的气孔率:用有机泡沫浸渍法制得的材料气孔率最大,可达72%;用煤炭粉作为造孔剂的多孔材料气孔率高于碳酸钙作为造孔剂的,用该法得到的多孔材料最大气孔率可达64%。在此基础上,对赤泥多孔材料进行了酸浸改性和负载TiO₂改性。通过酸浸改性,其表面粗糙度增加,显气孔率也有所提高。负载氧化钛改性采取的是共沉淀法,得到的负载材料经过480℃灼烧使其晶型转变为锐钛型,通过SEM表征发现TiO₂的尺寸在200-600nm之间。将采用两种造孔工艺制备的多孔材料进行了吸附废水中的PVA、富集水中的微生物、次甲基蓝脱色等一系列模拟废水的处理研究。实验表明,赤泥多孔材料对模拟纺织废水中的PVA具有一定的吸附作用。在室温条件下,用有机泡沫浸渍法制备的赤泥多孔材料可以将废水中PVA的浓度降低29%,处理时间约为50min;两种造孔工艺制备的赤泥多孔材料吸附PVA的动力学过程均符合二级吸附模型。赤泥多孔材料对微生物有富集作用,经过盐酸改性后能提高其对微生物的富集作用;而在其表面负载二氧化钛后,不再富集微生物,反而有杀菌作用。未改性的赤泥多孔材料对于次甲基蓝溶液脱色作用较为微弱,但负载TiO₂的赤泥多孔材料对次甲基蓝的脱色作用较为明显,当赤泥多孔材料的用量为溶液质量的8%时,脱色率可达22.8%。更多还原

【Abstract】 Red mud is a solid state industrial byproduct in the process of alumina extraction from bauxite. The alumina industry produced thousands million tons of dry red mud annually all over the world.The land filled red mud has caused a lot of environment pollution.Therefore efforts were performed for the effective utilization of red mud.Due to its steady chemistry compound,small grain size and big specific area,red mud can be applied in many fields.In this thesis,red mud and fly ash have been used to sinter different kinds of red mud-based porous materials（RMPM） via pore-forming agent method and polymer sponge method.The RMPM can get a good combined property at sintering temperature 1200℃when the mass ratio of red mud,fly ash and bentonite is maintained at 10:5:4.The porosity of RMPM can be controlled by changing the processes and pore-forming agents.It can reach a maximum of 72% when using the polymer sponge method,while it is 64%using pore-forming agent method.The pore-forming efficiency of coal powders is better than that of lime carbonate.The RMPM has been modified by acid dipping and TiO₂ carrying methods.Its roughness has increased and the porosity has risen after acid dipping treatment.Co-precipitation method has been used to carry TiO₂ on RMPM.The TiO₂ loaded RMPM has been calcinated under 480℃in order to make the TiO₂ transform to anatase.The diameter of TiO₂ particle is about 200-500 nm measured by SEM.These materials have been used in the simulated waste water to study their ability on the microbe beneficiation,polyvinyl alcohol（PVA） adsorption and decolouration of methylene blue solution.RMPM can absorb the PVA in simulated textile wastewater.The best mass ratio of RMPM to PVA solution is about 40:100 while the removal can reach the maximum of 29%after contacting for 50min.The rate and kinetics of sorption of PVA on RMPM fit the pseudo-second-order model.The acid dipping modified RMPM can beneficiate microbe more than the raw RMPM.But the TiO₂ carried RMPM has antiseptic ability.The TiO₂ carried RMPM can decolorize the methylene blue solution and the color-removing percentage can reach a maximum of 22.8%when the mass of TiO₂ carried RMPM takes 8%of that of the solution.更多还原