The influence of the temperature of calcination on the surface fractal dimensions of Ca(OH)(2)-derived sorbents

An investigation was carried out on the surface morphological features of two types of mesoporous sorbents derived from fine hydrated lime powder, termed H-CaO and C-CaO. Specifically, the surface fractal dimensions, d(SF)'s, of the sorbents obtained at various temperatures of calcination have been determined from their respective adsorption-desorption isotherms of nitrogen measured at 77 K, by a recently proposed thermodynamic method of analysis. A definite trend in the variation of d(SF) with the temperature of calcination has been discerned for both sorbents. Moreover, the d(SF) for each sorbent attained a maximum at 1273 K. The results of the present work may facilitate our understanding of various phenomena occurring on the irregular interfaces of heterogeneous systems at elevated temperatures. (C) 1996 Academic Press, Inc.