Texture-strength properties of the alumina-montmorillonite composite

The texture characteristics and strength properties of the molded alumina-m ontmorillonite composite are studied. The mixture is obtained by mixing sus pensions of activated clay and pseudoboehmite followed by drying (at 293 an d 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 streng th of samples are studied by varying the montmorillonite concentration in t he composite. The addition of 20-35 wt % clay largely results in a sharp in reduction of the macropore region and, correspondingly, provides the alumi na oxide average strength of the extrudates of similar to 10-12 MN/m(2), wh ich is sufficient for industrial supports. This excludes the stage of stand ard acidic peptization from the technological scheme of alumina production. The complex study of the porous structure of the composite by adsorption a nd mercury porosimetry combined with elements of percolation theory makes i t possible to predict the texture-strength properties of derivative materia ls.