Influence of Surface Area on the Density of Quartz heated at 1,300°–1,500° C

Abstract

DURING an investigation of silica brick it soon became apparent that the extent of the thermal alteration of quartz was dependent on its initial particle size. A search of the literature revealed only a few fragmentary pieces of information1–5. Most of this information merely compared the extent of alteration of two fractions, a fine and a coarse, and stated that the finer fraction is altered to the greatest extent. The finer fraction was coarse compared with the quartz used here. Therefore a systematic, qualitative investigation of the influence of the initial surface area of quartz on the extent of its thermal alteration, as measured by density changes and X-ray diffraction, was undertaken. The purpose of this communication is to emphasize graphically the extent of this surface area effect.