Abstract

This study was performed to measure expandabilities and scattering domain sizes (CSDs) of bentonite samples from Gampo and Yonil area, Korea, using X-ray powder diffraction (XRD), and to compare their experimental data with those of international standard bentonite samples (SAz-1, STx-1, and SWy-2). Most of Gampo and Yonil bentonite samples comprised randomly interstratified illite-smectite (R0 I-S), and their expandabilities ranged over 77-100%S_xrd from the saddle/001 method. The interstratification deformed 001 peaks of EG-solved samples (M?ring's first principle), which prohibited us from adopting these peaks to measure CSDs using BWA (Ber-taut-Warren-Averbach) method. CSDs of the bentonite samples with R0 I-S could be measured though Dehydration at 300^?C after K-saturation,where the deformation originated from the interstratification could be removed effectively. Gampo and Yonil bentonite samples showed that their mean CSDs ranged over 3.8-5.4 interlayers, and that their CSDs distributions were similar to those of Gonzales(STx-1) and Wyoming (SWy-2) bentonite samples.

Keywords

X-ray powder diffraction, bentonite, expandability, coherent scattering domain size, illite-smectite.