[T1] Powder Production

[14C-T1-03] Low-Temperature Foaming Mechanism of Silica-Based Solidified Products Prepared by Alkaline Activation

*K. Ishii¹, K. Hamasaki¹, M. Ishihara¹, M. Fuji¹ (1.Nagoya Institute of Technology, Japan)

Keywords:Shirasu, Silica, Alkaline activation, foam, Porous Material

The glassy volcanic sand produced mainly in the Kyushu region of Japan is called "Shirasu" and is composed of fine particles of silica-based compounds. Rapid heating to about 1000 ℃ makes the Shiras particles to expand and foam. The particles form a balloon-like hollow structure called a "Shiras balloons". In this study, solidified bodies of shirasu particles were prepared by alkali activation and foamed at low temperatures. The effects of sample preparation conditions, such as the concentration of added NaOH, treatment temperature, and time, on the foaming properties were investigated. We will report on the mechanism of low-temperature foaming of the silica-based solidified products.