Gravimetric determination of barium in zirconium metal and in certain zirconium salts

Barium may be determined gravimetrically in quantities ranging from 0.2 to 2.0 mg (± o.1 mg) in hydrated zirconyl chloride and in zirconium metal after complete separation of the zirconium. As much as 10 g of zirconium may be removed by a double precipitation in a (3 to 1) hydrochloric acid medium followed by a cupferron precipitation-chloroform extraction of the residual zirconium. The barium is then determined gravimetrically as barium sulfate in the iron-free, zirconium-free filtrate by precipitation with an excess of ammonium sulfate. As much as 0.015% barium has been found in impure zirconyl chloride, 0.004% in commercial “purified” zirconyl chloride, 0.000% barium in crystal bar zirconium metal and 0.003% barium in zirconium metal sheet. Reproducibility is 0.001%.