Wet and Dry Pore Size Distribution in a Kaolinitic Soil Before and After Removal of Iron and Quartz

Summary A kaolinitic soil was treated chemically to remove iron and quartz. Before and after treatment the properties of the soil were, respectively: iron content, 7 and 1%; quartz content, 21 and 0%: water content at saturation (water/kaolin content, g/g), 0.40 for both, of which 0.34 was in pores for which the Kelvin radius r j , was ≤35 nm. Porosity and pore size distribution (PSD) up to this pore size were studied using nitrogen sorption, mercury injection, pressure membrane equilibration and low temperature scanning microcalorimetry (DSC). These analyses justified interpretation in terms of kaolinite content alone. The PSD was unaffected by the removal of iron or quartz or the moisture content of this soil. New DSC techniques show that the pore spaces within the treated samples ( r j ≤ 35 nm) are largely unconstricted, and thus, an experimental curve relating temperature depression for melting to pore size is possible using only one sample.