A NEW SIMULATOR OF MERCURY POROSIMETRY FOR THE CHARACTERIZATION OF POROUS MATERIALS

Information about the pore structure of permeable solids is embedded in mercury intrusion-retraction curves in a highly convoluted form. Any attempt to derive a "pore size distribution" must inevitably depend on postulates concerning the pore shapes and the pore network skeleton. For an important class of permeable materials the pore space can be represented as a matrix of chambers interconnected through narrow throats. Information about the chamber size distribution and the network skeleton can be obtained from serial tomography. Information about the throat size distribution can then be obtained by deconvolving the intrusion-retraction curves. To this end, a reliable mercury intrusion-withdrawal simulator must be available. Such a simulator for three-dimensional chamber-and-throat networks is developed here. This simulator takes into account the mechanisms by which mercury menisci move in pores and stop at entrances to throats or (in certain cases) chambers. It also takes into account the mechanism of snap-off, which leads to the disconnection and entrapment of mercury in the form of ganglia. The sequence in which mercury menisci move and threads break is also taken into account. The simulator is used to study the effects of the throat size distribution, the chamber size distribution, the coordination number, and the contact angle on the capillary pressure curves. © 1990.