Solubility of manganese and iron in sodium

Non-availability of data on the solubility of manganese in sodium and the high scatter of reported data on the solubility of iron in sodium prompted this study to establish their solubility in sodium. Initial experiments were conducted using a double compartment capsule with overflow sampler. The solubility values obtained were found to be high and showed a strong dependence on the oxygen concentration. To minimise the contribution of particulates to the observed solubility values, the capsule was modified to include a filtration step while sampling. Another approach to measuring the solubilities of these metals is the use of a compact pumped isothermal loop which has been constructed and is in operation. This has provisions for measuring the oxygen potential in sodium and for sampling sodium both for oxygen and trace metals. This paper describes the experimental details and present the measured solubilities of iron and manganese in sodium as a function of temperature and oxygen concentration. The solubility data have been used to deduce the relevant thermodynamic parameters. (orig.)