PREPARATION OF BARIUM SULFATE HAVING LARGE PARTICLE SIZE

摘要

PURPOSE:To prepare the titled barium sulfate suitable as pigment, cosmetics, plastic additive, etc., by reacting barium sulfide continuously with sulfuric acid under specific conditions (the pH of the reaction sytem, electrical conductivity, rate of feeding, etc.). CONSTITUTION:A barium sulfide solution and sulfuric acid are supplied continuously to the reaction system, and made to react with each other to obtain the titled compound. The reaction is carried out by keeping the reaction system in a weakly acidic state (about 3-7pH), the electrical conductivity of the system to 0.1-100muOMEGA/cm, the ratio of F/V to 0.1-1 (wherein F is the total volume of the supplied liquid, i.e. the sum of the water in the barium sulfide solution and sulfuric acid and 1/4.5 of the produced barium sulfate, and V is the capacity of the reaction system), and the slurry concentration in the reaction system to 5- 320g/l. The obtained barium sulfate is a laminar particle having a diameter of about 2-20mu, and can be densified by heating at = about 70 deg.C and =12pH or =2pH for about =1hr.