水熱反応により合成したゾノトライト凝集体の分散化

抄録

The dispersion of xonotlite aggregate was investigated by adding KOH solution in hydrothermal process and ultrasonication in xonotlite suspension. Xonotlite was synthesized under saturated steam pressure 2.4 MPa at 220°C in suspensions of CaO-SiO₂-KOH-H₂O system with high purity or industrial raw materials. Characterization of products was determined by means of Xray diffraction, specific surface area and scanning electron microscopic observation.
The primary particles of xonotlite aggregate were grew by increasing K/ (Ca + Si) atomic ratios and that the dispersion of the aggregate was accelerated. In the case of high purity raw materials, the average length of primary particles was grew to 8.3, μm under the condition of K/ (Ca + Si) atomic ratio of 0.20 but the dispersion of the aggregate was insufficiency. Accordingly, the complete dispersion was investigated by ultrasonication with frequency 45 kHz in xonotlite suspension. The complete dispersion time of the aggregate of primary particles with average length of 8.3, μm was reduced at 0.5 minutes. In the case of industrial raw materials, the dispersion time was prolonged until 2 minutes due to control crystal growth of primary particles.