alternatively, the carrier can be calcined after contacting the carrier with the sulfating agent and before contacting the carrier with an organic chromium compound.
可选地,可以在载体与硫酸化剂接触之后且载体与有机铬化合物接触之前煅烧载体。
the invention provides a method for preparing a polymerization catalyst. the method comprises contacting a carrier comprising alumina with a sulfating agent and with chromium.