Determination of traces of aluminum and manganese in zirconium and its alloys

A method for the determination of aluminum and manganese in a reactor material, Zircaloy-2 which contains 1.201.70% of tin, 0.070.20% of iron, 0.030.08% of nickel and 0.050.15% of chromium, has been established. The method can be used for determining down to 5 ppm of both aluminum and manganese in zirconium bearing materials. Up to 2 g of the sample is dissolved with sulfuric acid and ammonium sulfate. Prior to the determination, zirconium is removed by extracting its cupferron chelate with chloroform. From 1 to 2 N sulfuric acid solution, not more than 400 mg of zirconium is extracted, while aluminum and manganese remain quantitatively in the aqueous solution. The extraction should be carried out twice to eliminate zirconium completely. Fifteen ml of 8% cupferron solution is used for each 100 mg of zirconium at the first extraction, and 3 ml of the same solution is used at the second extraction. After removal of zirconium and decomposition of the residual cupferron, aluminum is determined by extracting its 8-hydroxyquinoline (oxine) complex from a solution (pH 5.0±0.2) containing cyanide, and by measuring the absorbance at 390 mμ. Chromium must have been removed by extracting from a solution of pH 5.0±0.2 as its 2-methyl oxine complex, before the aluminum determination. Manganese is determined on another aliquot which has been treated with cupferron, by extracting its 2-methyl oxine complex and by measuring the absorbances at 395 and 580 mμ. Interferences from chromium, nickel and lead are eliminated by adding citrate, cyanide and EDTA as masking agents to the aqueous solution (pH 12±0.5).