PROCESS FOR PREPARING A CORE-LAYER MATERIAL HAVING GOOD MECHANICAL STRENGTH

摘要

A process is described for preparing a spherical material comprising a porous core coated with a continuous and homogeneous porous layer, the degree of attrition of said material being less than 20%. Said preparation process comprises a) bringing a bed of spherical particles constituting the core of said material into contact with a suspension containing an inorganic binder in order to form a solid having a pre-layer around said core; b) bringing the solid derived from step a) into contact, in a stream of hot air, with a powder constituted by spherical particles of an inorganic oxide and a suspension containing an inorganic binder and an organic binder in order to form a solid the core of which is coated with at least one continuous and homogeneous porous layer, the ratio of the (mass of anhydrous inorganic binder/volume of powder particles) being in the range 0.05 to 1 g.mL−1; c) drying the solid derived from said step b); and d) calcining the solid derived from said step c).