Phyllosilicate-supported catalyst for the polymerisation of olefins

A particulate phyllosilicate mixture comprising a mixture containing a phyllosilicte belonging to the smectite group and a phyllosilicate belogning to the mica group, the phyllosilicate particle having a content of the phyllosilicate belonging to the smectite group of 0.1 to 50% by weight and optionally satisfying the following requirements (a) to (c): (a): the average particle diameter is 20 to 1000 mu m with not more than 20% of the total number of particles being accounted for by particles having a particle diameter of not more than 10 mu m; (b): the crushing strength of the particle is not less than 0.5 MPa as measured with a microcompression tester and (c): the bulk density of the particle of not less than 0.6 g/cm . Polymerization of olefins with catalyst comprising the particulate phyllosilicate mixture as a carrier or support for the catalysts is also disclosed