The conventicnal sulfate determination by gravimetrically precipitating barium sulfate is very tedious and time consuming. The present technique uses an ion exchanger so the sulfate can be titrimetrically determined as sulfuric acid. An analysis can be completed in 30 minutes. This method is being used for the routine analysis of sulfate in mixtures of gypsum, anhydrite, calcium oxide, and calcium sulfide. The mixturrs are produced from laboratory and pilot plant investigations on the i