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16, Processing Chemistry L. M. Ferris


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Work done at Argonne National Laboratory3 with LiC1-LiF solutions indicated that high lithium and bismuth concentrations (up to 0.1 mole %) might be expected in LiCl that is in equilibrium with lithiumbismuth solutions in which the lithium concentration is 5 to 50 at. %. Concentrations of this magnitude could have a significant effect on the performance of the metal transfer process. Consequently, we have initiated a study of the equilibrium distribution of lithium and bismuth between molten LiCl and liquid lithiumbismuth solutions. The results of this study should aid in optimizing operating conditions for the metal transfer process. In this study, LiCl containing less than 0.05 mole % LiOH was equilibrated with various lithium-bismuth solutions at 650°C. Thorium was added to the system in some cases to minimize the oxide and hydroxide concentrations in the salt. The apparatus and general procedure have been described elsewhere? The equilibrium lithium concentration in the salt phase was generally determined by removing a salt sample with a stainless steel sampler, hydrolyzing the sample in water, and measuring the amount of hydrogen evolved by a gas-chromatographic procedure. Samples for bismuth analysis were taken with quartz samplers. When the

Studies relating to the metal transfer process’’2 for the removal of rare-earth and other fission products from MSBR fuel salt were continued. Included in this work were measurements of the equilibrium distribution of lithium and bismuth between liquid Li-Bi alloys and molten IiCl, and of the mutual solubilities of thorium and selected rare earths in liquid bismuth. The equilibrium precipitation of Pa205 from MSBR fuel salt by sparging with HF-H20-H2-Argas mixtures was also studied. The effect of temperature on the solubility of Pa205 in fuel salt that was also saturated with Tho2 was determined. Studies relating to the chemistry of fuel reconstitution were begun. The initial phase of this work involves a study of the reaction of gaseous UF6 with UF, dissolved in MSBR fuel salt.


L.M. Ferris

J. F. Land

In the metal transfer process,’ s2 iare earths and the attendant small amount of thorium would be stripped from the LiCl acceptor salt into lithium-bismuth solutions having lithium concentrations of 5 to SO at. %. t

1. L. E. McNeese, MSR Bogram Semiannu. Bog. Rep. Feb. 28,1970,0WL4548,p.277. 2. D. E. Ferguson and Staff, Chem. Technol. Div. Annu.

Bog. Rep. Mar. 31.1971, ORNL4682,p. 2.

3. E. J. Cairns et al., Galvanic Cells with Fused-Salt Elecnolytes, ANL-7316(November 1967), p. 119. 4. L. M. Ferris, J. C. Mailen, J. J. Lawrance, F. J. Smith, and E. D.Nogueira, J. Inorg. Nucl. Chem. 32,2019 (1970).

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