Process for preparing catalysts and catalyst compositions

A catalyst composition for olefin polymerization, the catalyst composition comprising:

• a) at least one metallocene compound;
• b) optionally, at least one co-catalyst;
• and
• c) at least one support-activator comprising a calcined smectite heteroadduct, the smectite heteroadduct comprising the contact product of [1] a colloidal smectite clay and [2] a heterocoagulation reagent comprising at least one cationic polymetallate in a liquid carrier and in an amount sufficient to provide a slurry of the smectite heteroadduct having a zeta potential in a range of from about positive (+)25 mV (millivolts) to about negative (−)25 mV.

A process for polymerizing olefins comprising contacting at least one olefin monomer and a catalyst composition under polymerization conditions to form a polyolefin, wherein the catalyst composition comprises:

• a) at least one metallocene compound;
• b) optionally, at least one co-catalyst;
• and
• c) at least one support-activator comprising a calcined smectite heteroadduct, the smectite heteroadduct comprising the contact product of [1] a colloidal smectite clay and [2] a heterocoagulation reagent comprising at least one cationic polymetallate in a liquid carrier and in an amount sufficient to provide a slurry of the smectite heteroadduct having a zeta potential in a range of from about positive 25 (+) mV (millivolts) to about negative (−)25 mV.

A method of making a support-activator, the method comprising:

• a) providing a colloidal smectite clay;
• b) contacting in a liquid carrier the colloidal smectite clay with a heterocoagulation reagent comprising at least one cationic polymetallate and in an amount sufficient to provide a slurry of a smectite heteroadduct having a zeta potential in a range of from about positive (+)25 mV (millivolts) to about negative (−)25 mV;
• and
• c) isolating the smectite heteroadduct from the slurry.