Abstract: A Prepolymerized catalyst component for the polymerization of olefins comprising a solid catalyst component which comprises Mg, Ti, and chlorine atoms and an electron donor (ID) said prepolymerized catalyst component being characterized by the fact that: the electron donor (ID) is constituted by at least 80% mol of 1,3 diethers with respect to the total molar amount of electron donor compounds; the prepolymerized catalyst has a porosity due to pores with diameters up to 1 ?m of less than 0.2 cm3/g; it contains an amount of ethylene prepolymer of less than 45% with respect to the total weight of prepolymerized catalyst.

Abstract: A Prepolymerized catalyst component for the polymerization of olefins comprising a solid catalyst component which comprises Mg, Ti, and chlorine atoms and an electron donor (ID) said prepolymerized catalyst component being characterized by the fact that: the electron donor (ID) is constituted by at least 80% mol of 1,3 diethers with respect to the total molar amount of electron donor compounds; the prepolymerized catalyst has a porosity due to pores with diameters up to 1 ?m of less than 0.2 cm3/g; it contains an amount of ethylene prepolymer of less than 45% with respect to the total weight of prepolymerized catalyst.

Abstract: The present disclosure relates to a process for preparing a MgCl2-alcohol adduct which comprises (a) forming a mixture of an MgCl2-alcohol adduct in molten form and a liquid which is immiscible with the adduct, (b) subjecting the mixture to a shear stress to obtain an emulsion, and (c) rapidly cooling the emulsion to solidify the disperse phase and collecting the solid adduct particles, the process being characterized by the fact that step (b) is carried out in a device comprising a first outer and second inner cylindrical members that define an annulus between them, wherein at least one of the cylindrical members rotate with respect to the other.