Spectrophotometric Determination of Rhenium in Roasted Sample of Molybdenum Concentrate

Spectrophotometry was applied to the determination of rhenium in roasted sample of molybdenum concentrate. The optimized conditions found were as follows:① wavelength of determination was 426 nm; ② coloration in HCl (1+1) solution; ③ amount of 350 g·L^-1 potassium rhodanate solution was 1.0 mL; ④ amount of 20 g·L^-1 stannous chloride solution was 1.0 mL; ⑤ amount of H₂SO₄ was 3 mL; ⑥ heating temperature was 85℃; ⑦ heating time was 1.5 h; ⑧ amount of rhenium reagent was 1.0 mL; ⑨ pH of the sample solution was about 9. Linear relationship between values of absorbance and mass concentration of rhenium was obtained in the range of 3.0-30.0 mg·L^-1, with detection limit (3s/k) of 1.0 mg·L^-1. The proposed method was applied to the analysis of roasted sample of molybdenum concentrate, giving results in consistency with the values obtained by ICP-AES with RSD's (n=7) in the range of 1.1%-2.2%. Test for recovery was performed by standard addition method, giving values of recovery in the range of 94.0%-106%.