Process for preparing ultra-fine barium sulphate by precipitation

摘要

A process is described for preparing finely-divided precipitated barium sulphate by combining separate aqueous solutions which contain equivalent amounts of barium ions and sulphate ions respectively, and separating off the precipitate. For the purpose of preparing precipitated barium sulphate having a primary particle size of less than 1 micron, the aqueous solutions of the reactants are, in a closed reactor, continuously broken up into a large number of part volumes, these are combined to give discrete precipitation volumes of an average volume of less than 1 microlitre ( mu l) and the suspension of the precipitate formed is continuously discharged from the reactor.