order of 2 3 the major cell voltage component in this method would be the resistive drop associated with the molten salt bath and would raise the cell voltage by several volts over the emf in contrast to this prior art method the prior art method as described in u s pat no 4 790 917 uses two aluminum lithium pools to extract lithium in this method assuming that the activity of lithium in aluminum is nearly the same as the activity of lithium in an aluminum alloy the nernst potential or emf is a function of the respective lithium concentrations in the two aluminum pools these concentrations are dependent on the relative masses of the two pools and time using the same starting conditions as set forth for derivation of the curves in fig1 but with a 50 gram aluminum cathode pool the nernst potentials and weight percent of lithium over time are depicted in fig2 as can be seen from fig2 initially the cell has a negative nernst potential which acts as a cell driving force to equalize the lithium potentials in the two aluminum pools however over time and as lithium concentration increases in the cathodic region the cell emf becomes positive all other cell components being equal this cell would operate at a lower cell voltage than the previously described electrorefining cell in one aspect the inventive process provides improvements over these prior art processes regarding cell emf by using a pure tin pool as the cathode in the electrorefining cell tin has a very high affinity for lithium as evidenced by the very low activity coefficient for lithium in tin at a temperature of 670 u00b0 c the activity coefficient for infinitely dilute lithium in tin is.