Nanometer-sized xonotlite fibers have great potential application in manyfields. The traditional method of preparing ultra fine xonotlite fibers uses the ultra fine andhighly active silica as the major raw materials, which is not only expensive but also difficult toprepare the xonotlite fibers with diameters around 100 nm. In this study, the ultra fine xonotlitefibers with diameters around 100 nm were prepared by an autoclaving method. The preparation waslow-cost oriented by using natural powder quartz and lime as the major raw materials. Theintergrowth of the fibers formed thin shell hollow balls or ellipsoids, namely the secondaryparticles. The length of the nanometer-sized xonotlite fibers was around several microns. The fibersand their secondary particles were produced at 216 deg C for 6 h with a continuous stirring of300-500 r/min. Zirconium oxychloride was used as an additive. The experiments show that zirconiumoxychloride has an enormous effect on the growing habit of xonotlite crystals and plays an importantrole in controlling the diameter of the xonotlite fibers.
Four reactors of up-flow anaerobic sludge blanket (UASB) were concurrentlyoperated to examine the effects of the xonotlite secondary particles on promoting the sludgegranulation during the starting-up stage at room temperature. The results show that the putting ofthe xonotlite secondary particles into the UASB reactors can increase the basicity of the reactingliquid significantly. The particles can act as the media for biomass accumulation. Thus, thegranulation process of the sludge within the reactor can be largely promoted by the specialperformances of the particles both in physical and chemical aspects.
