沸石化凝灰岩の加熱発泡性 (I)
未利用岩石資源の利用に関する研究 (第2報)
1984 年 100 巻 1152 号 p. 67-72
詳細
1984 年 100 巻 1152 号 p. 67-72
The bloating properties of sedimentary zeolites existing enormously in Green Tuff region of our country were investigated. Pelletized bodies (9-12mm diameter) prepared from pulverized zeolites were fired in the range of 900-1350°C. Then physicochemical properties, such as specific gravity, water absorption, crushing strength etc., of the pellets were measured. Moreover, 38 mixtures prepared from mordenite tuff, silica, alumina and ferric oxide were fired in order to make clear the optimum bloating range in chemical compositions.
The results obtained are summarized as follows;
In many cases, air dried pellets had high crushing strength enough to permit the firing by rotary kiln. Pellets started to bloat at temperatures above 1150°C and the bloating extent increased with raising the temperature. Most of the pellets fired at higher temperature than 1100°C were impervious and their specific gravity was about 2.3-0.4. Crushing strength of the fired pelletes whose specific gravity were about 1.2-1.3 were in the range of 120-170kg, and it was about 2 times that of artificial light weight aggregates commercially produced. By the results of X-ray analysis, chemical and thermal analysis, it was guessed that a common gas-forming component in sedimentary zeolites concerning with the bloating was ferric oxide.
From the firing tests of the above-mentioned mixtures, the optimum contents of silica, alumina and flux for the bloating were ascertained to be in the range of 60-70%, 10-25% and 10-20%, respectively.
