Abstract: A process and apparatus for producing hydraulic cements such as portland cement utilizing electrical energy as the heat source is described. The electrical heat source includes a plasma arc torch operating in the transferred mode. A feature of the apparatus and process is in utilizing a liner within the furnace composed of a material having substantially the same chemical composition of the cement that is to be produced in the furnace. Preferably the feed materials properly proportioned to have the desired constituency of cement are fed below the melt of the furnace. The process is compact and efficient relative to the conventional rotary kiln used for producing cement.