Determination of Oxygen in Halide Fluorotantalate Melts by IR Spectroscopy

The possibility of determining oxygen as impurity in halide melts containing potassium heptafluorotantalate by IR spectroscopy was investigated. These melts are used for obtaining tantalum powders by the sodium–thermal method. It was found that a linear correlation exists between the oxygen concentration in the melt c _O(c _O= 0.05–1.0 wt %) and the ratio of intensities of IR absorption lines in the region of 1200–400 cm^–1. This correlation can be used for determining oxygen in the melt and for predicting the concentration of this element in sodium–thermal tantalum powders.     

Formation of Nickel-Tantalum Compounds in NaCl-K2TaF7 Melts

The formation of nickel-tantalum compounds in halide fluorotantalate melts was studied at 750°C. The mechanism of electroless tantalum plating onto nickel is considered and it is suggested that disproportionation underlies the spontaneous transfer.     

Diffusion Coating of Nickel with Tantalum in Chloride-Fluorotantalate Melts

The effect of temperature and time on the diffusion saturation of nickel with tantalum in molten salt mixture NaCl-14 mol % K₂TaF₇ in the presence of metallic tantalum powder was studied, and characteristics of the obtained diffusion coatings were analyzed.