The determination of aluminum in ferrovanadium using precipitation reaction of iron and vanadium with barium chloride was studied. Vanadium were precipi-tated by barium chloride in alkaline solution, and aluminum could be collected quantitatively at pH 12.5〜13.0, ferric ion did not interfere with the determination. Vanadium reacted quantitatively with barium, in a mole ratio of V/Ba as l/(1.4〜1.6), to form Ba_5Cl(VO_4)_3 or Ba_3V_2O_8. The standard procedure is as follows : Transfer 0.500 g of the sample to a 250 ml beaker, and dissolve in 20 ml of H_2O, 5 ml of HCl and 10 ml of HNO_3. Dilute to 150 ml with hot water and heat until salts dissolve. Add 10ml of 25 % BaCl_2 solution and 25 ml of 50 % NaOH solution, stirring thoroughly. Boil a few minutes and transfer this solution to a 250 ml volumetric flask, cool to room temperature, and dilute to the mark. Filter through a fine paper, transfer 100 ml of filtrate to a 500 ml beaker and dilute to 250 ml. Adjust the pH to 1.0 with HCl and then to 3.0±0.1 with 20 % NH_4Ac solution. Boil a few minutes and add 4 or 5 drops of Cu-PAN indicator solution. Titrate with EDTA solution until the color changes from wine red to yellow, and then add 1 or 2 ml in excess. Record the buret reading and boil a few minutes. Titrate the excess EDTA with CuSO_4 solution to a wine red end point. This method is easy to remove iron and vanadium, and, in addition, highly accurate results can be obtained.
