Nitrogen-nitride, hydrogen-hydride and oxygen-oxide reactions in liquid reactive metal-tin alloys, and metallurical applications

A Sieverts-type apparatus was used to study the reactions of certain gases with reactive metals dissolved in metal solvents. The overall reaction can be represented by the following equation: xM + y/2 G2(g) = M/sub x/G/sub y/(s) where M represents Th, Ti, Zr, Hf, U, Mg, Pr, Gd, or Y and G stands for N, H, or O. The pressure of the gas in the system was below one atmosphere. Experimental efforts were mainly concentrated on studies of the nitriding of Th, Ti, Zr, and Hf in the liquid solvent tin. No solubility data for nitrogen in these alloys were obtained since its solubility was below the detection limit of the apparatus. The equilibrium thermodynamics of the nitride formation reactions in molten Th-Sn, Ti-Sn, and Zr-Sn alloys were experimentally determined. The activities and activity coefficients of the nitride-forming elements were obtained from the experimental data. The equilibrium constants for these nitride formation reactions have also been determined as a function of temperature. The standard free energies of the nitride formation equations on the weight percent activity scale were established for each individual reaction. The experimental results were applied to guide the experimental evaluation of the potentials of three possible industrial metal separation processes; the Th-U, Zr-U and Zr-Hf systems were chosen for demonstration