| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fine aggregate for lightweight refractory concrete useful for producing lightweight refractory concrete having excellent refractoriness. <P>SOLUTION: The removal of hyperfine particles by the cleaning of ash with a fine particle diameter and classification therefor are performed, thus a fine aggregate with a diameter of ≤5 mm in which the inside comprises moisture Wi and the surface is covered with surface water Wo is obtained. The fine aggregate is subjected to drying treatment at 670 to 730°C, so as to remove the surface water Wo and to generate each space S in which a part of the moisture Wi is removed at the inside. Thereafter, the same is subjected to heating treatment at 800 to 850°C to increase the ratio of amorphous components, and further, each space S including the remaining moisture is left at the inside. Thereafter, bubbles W on the surface layer of the fine aggregate is subjected to clogging treatment with a coating material. Further, cement and water are added thereto, so as to perform viscosity increasing treatment, and a coating C whose viscosity is made high by increasing pH by OH-ions released from the cement is formed on the surface of the fine aggregate. Finally, the fine aggregate having a water content of 3 to 5 wt.% is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT |
