Used in the purification of brine solutions in caustic chlorine plants by precipitating sulfate impurities. Commonly employed in qualitative analysis to test for the presence of sulfate ions, forming a characteristic white precipitate of barium sulfate. Applied in the heat treatment of steel, where it acts as a salt bath medium to improve hardness and wear resistance. Also used in the production of pigments and in electroplating processes to enhance conductivity and deposit quality.