As part of its goal to help maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines, U.S. Department of the Interior, is investigating a fused-salt electrolytic procedure for producing zinc metal. A previous report described preliminary, small-scale work on the fused-salt electrolysis of zncl2. The present report covers a more detailed investigation of the properties of zncl2-alkali metal chloride electrolyte systems in relation to the production of zinc metal and also discusses electrolysis in large-scale, internally heated cells. The effect of composition on bath stability, current efficiency, cell voltage, and liquidus temperature was determined for the zncl2- nacl-kcl, zncl2-nacl-licl, and zncl2-kcl-licl electrolyte systems. An electrolyte composed of 38 mole-pct zncl2, 31 mole-pct nacl, and 31 mole-pct kcl gave the best overall results. Sludge (zno) formation in the zncl2-nacl-kcl, zncl2-kcl-licl, and zncl2-kcl systems was investigated during prolonged electrolysis. The zncl2- kcl-nacl electrolyte showed the least sludge formation. A 1,500-amp cell was operated using the zncl2-nacl-kcl electrolyte at 500 deg c. Zinc metal was produced at the rate of 4.0 Lb/hr with a current efficiency of 95 pct.