Rapid method for the determination of Beryllium in presence of Iron and Aluminium

Abstract

All the known colorimetric methods for the estimation of beryllium require prior separation of iron. Small amounts of iron and aluminium are always present in the beryllium solution used in the N.M.L. beryllia pilot plant. The method of Osborn and Stross for the rapid photometric determination of beryllium with the dye p-nitrobenzene-azo-orcinol in the presence of aluminium has been modified to carry out the estimation in presence of both iron and aluminium. The effects of the concentrations of (1) dye-solution (2) tartrates and citrates and (3) free alkali, on the absorption have been studied for determining the optimum conditions for the estimation. It has been found that the method may be used for concentrations sodium tartrates (5%), 5cc of caustic soda solution (2%), 8cc of dye solution and 0-0.25 mg each of iron and aluminium. The calibration graph is liner up to 0.06 mg of beryllium and is fairly reproducible. Beryllium in samples of Rajasthan beryl containing about 4.5, 8.6 and 1.0% of Be, Al and Fe respectively has been determined by this method and determined gravimetrically. The values of beryllium obtained compare very closely. Whereas it require days for the estimation of beryllium in beryl by the gravimetric method, the colorimetric analysis can be done much more quickly by the method developed here. Determination of beryllium in solutions used in the pilot plant can be done within five to ten minutes.