QUANTITATIVE SPECTROSCOPIC DETERMINATION OF NIOBIUM IN TITANIUM AND ZIRCONIUM MINERALS

The methods for the preparation of standards for the determination of Nb in eudialite, sphene, rincolite, astrophyllite, and lamprophyllite are described in detail. The conditions of the taking of an exposure are: Test sample l0 to l5 mg, upper electrode ground to a wedge-shaped point, a crater 5 mm deep and 3 mm in diameter drilled in the lower electrode, time of complete evaporation of specimen 4-5 min with a l0-amp current. Calibration curves were plotted according to 3-4 standard samples. The spectrophotometry was conducted according to the lines of Nb 2671.9 and 27l6.6 angstrom. The results of the determination of Nb in 20 specimens parallel with the determination of Nb in them by the chemical method are adduced. The average magnitude of deviation from the chemical analysis consisted of the J-57 engin l3% with an Nb content of 0.15 to 5.0%.