Texture–Strength Properties of the Alumina–Montmorillonite Composite

Abstract

The texture characteristics and strength properties of the molded alumina–montmorillonite composite are studied. The mixture is obtained by mixing suspensions of activated clay and pseudoboehmite followed by drying (at 293 and 393 K) and calcination (at 873 K). It is a promising support for cracking and hydrotreating catalysts. The changes in the specific surface area; the volumes of micro-, meso-, macropore, and medium-size pores; and the strength of samples are studied by varying the montmorillonite concentration in the composite. The addition of 20–35 wt % clay largely results in a sharp in reduction of the macropore region and, correspondingly, provides the alumina oxide average strength of the extrudates of ∼10–12 MN/m2, which is sufficient for industrial supports. This excludes the stage of standard acidic peptization from the technological scheme of alumina production. The complex study of the porous structure of the composite by adsorption and mercury porosimetry combined with elements of percolation theory makes it possible to predict the texture–strength properties of derivative materials.