A problem of protection of electrolytic cell members against affecting the aggressive salt and liquid metal phases during preparation of current-supplier master alloys with simultaneous good contact of liquid cathode and current supplier is considered. The thermal characteristics of skull electrolytic cell with liquid cathode under steady state conditions are measured for preparation of Al and Zn alloys with rare earth metals. The results of measurements are used in simulation of heat balance of apparatus. The computations showed that the energy consumption changes proportionally to the variation of linear dimension of apparatus.