Abstract: A plasma arc waste treatment furnace is equipped with a plasma arc torch having an electrode formed from a conductive refractory material. The refractory electrode can be operated at very high temperatures and does not need to be water-cooled. This eliminates a need for de-ionized water used in prior art furnaces. Arc erosion takes place very slowly and this results in long operating intervals of the furnace between shutdowns needed for electrode replacement. The electrode can be successfully operated as a cathode and this mode of operation improves melting efficiency.