Higher HNO Research Articles

Reactions of uranium mononitride, thorium monocarbide and uranium monocarbide with nitric acid and other aqueous reagents

Uranium mononitride was inert at 80° in water, 3–12 M HCl, 1 M H 2SO 4, 1 M NaOH, 1 M NaNO 3, and 5 M NH 4NO 3; however, it did react in 1–2·5 M Al(NO 3) 3. The nitride reacted with 0·5–15·8 M HNO 3 to give gaseous mixtures of N 2, N 2O, NO, and NO 2 (NO 2 was produced only when the acid concentration was 6 M or higher). In reactions of thorium monocarbide with 0·1 to 1 M HNO 3 at 90°, both hydrolysis (yielding mainly methane) and oxidation (yielding CO 2, N 2, and nitrogen oxides) of the carbide took place; at higher HNO 3 concentrations, only oxidation occurred. The principal reaction of UC or ThC with 4 and 6 M NH 4F at 80° was: ▪

Protective films on ta in high temperature HNO 3 acid and cupric chloride aqueous solutions

Protective films on ta in high temperature HNO 3 acid and cupric chloride aqueous solutions

Interrelationships in the solvent extraction behaviour of scandium, thorium, and zirconium in certain tributyl phosphate-mineral acid systems

The extraction behaviour of Sc and that of Th in the aqueous HCl-TBP (tributyl phosphate) system differ sufficiently that these elements are readily separable. Although the respective extraction curves tend to converge as the HCl concentration is lowered, they do not intersect. In contrast, the Sc and Th extraction curves in the HNO 3-TBP systems mutually cross. The complete Zr extraction curves have not been determined, but the Zr extraction curve in the HNO 3-TBP system is shown to cross both the Sc and Th curves. Consequently, in this system, any one of the three elements may be separated as product from the other two as contaminants. In the HCl-TBP system, the TBP dependency of the extraction coefficients for Sc and Th are not readily interpretable. In the HNO 3-TBP system the TBP dependencies are operationally fourth-power at high HNO 3 concentrations and considerably less than fourth-power at intermediate and low HNO 3 concentrations. The mutual separation of a ThSc mixture and of a ThZr mixture in the HCl-TBP system and the isolation of each of the three elements as product from a ScThZr mixture in the HNO 3-TBP system are demonstrated.