Silica-stone for Fire Brick Produced in Japan

Abstract

The so-called “Akashiro” & “Aoshiro” silica-stone of good quality is an important material for five brick which is at present used for Siemens-Martin furnaces in Japan. For this purpose, such a conditions as follows of silica-stone are necessary : (i) SK>33 (ii) no rapid expansion or shrinking (iii) intense resistance against slag.
This report treats yielding places, distribution, chemical and mineralogical composition, texture, and origin of the silica. stone in Japan.
The writer considers that the silica-stone is a sort of methamorphic rocks by hydrothermal process. Ore reserves of the silica-stone is large enough to answer for 20 years' supply, if present yield is to continue. But it is necessary to explore the are of Tohoku (North East Japan) & Hokkaido in view of transportation conditions.