@article{oai:ir.kagoshima-u.ac.jp:00000682,
 author = {島田, 欣二 and SHIMADA, Kinji and 福重, 安雄 and FUKUSHIGE, Yasuo and 平田, 好洋 and HIRATA, Yoshihiro and 松下, 浩司 and MATSUSHITA, Koji},
 journal = {鹿児島大学工学部研究報告, The research reports of the Faculty of Engineering, Kagoshima University},
 month = {Nov},
 note = {Opaline silica rock (94.2% SiO_2) occurs in Iohjima island, Kagoshima Prefecture. A mixture of the silica powder and milk of lime (calcined CaCO_3) was stirred in a teflon container of autoclave and treated hydrothermally under the following conditions; molar ratio of Cao/SiO_2 1.05, weight ratio of water/solid 5 to 30, and temperature 80°-250°C foo 1 to 50 h. Effect of firing temparature of raw silica and CaCO_3, additive of heavy metal ions such as Ni^{2+}, Cr^{3+} and Fe^{3+}, and the condition of reaction on the phase of products and the morphology was examined using the X-ray powder diffraction test (XRD), the differential thermal analysis (DTA), the thermal gravimetric analysis (TGA), the infra-red absorption spectroscopy (IR), and electron microscopy. The results showed that the products treated hydrothermally above l80°C were C-S-H(CaO-SiO_2-H_2O), α-C_2SH(2CaO･SiO_2･H_2O), tobermorite(6CaO･5SiO_2･6H_2O) and xonotlite(6CaO・6SiO_2･H_2O), 
especially promoted by the addition of Cr^{3+} in tobermorite and promoted with increasing of crystlline silica (cristobalite) by calcination in xonotlite.},
 pages = {125--135},
 title = {火山作用と関係ある無定形ケイ酸の性質とその応用的研究 : 第35報 オパール質ケイ石を原料とするケイ酸石灰塩水和物の合成},
 volume = {28},
 year = {1986}
}