Caractérisation des minéraux finement divisés par physisorption. Théories les plus employées et instrumentation. / Characterization of finely grained minerals by physisorption. Most common theories and instrumentation

Characterization of finely grained minerals by physisorption. Most common theories and instrumentation The morphometric and textural properties of any particulate or porous solid can be determined using physical adsorption experiments. The different shapes of adsorption isotherms are described with reference to their physical significance, methods are deduced to determine the specific surface, the mesopores distribution and an evaluation of the microporosity. Reciprocal thermal analysis is proposed as a method to produce an adsorbing surface in a reproducible state. Concerning measurement devices, several methods are proposed to determine the adsorption isotherms : the conventional adsorption volumetry, the chromatographic-like method, the quasi-equilibrium volumetry and the adsorption gravimetry. The adsorption enthalpies are directly measured by gas adsorption microcalorimetry, or indirectly, using the isosteric heat determination.