Abstract: A plasma torch electrode has a copper outer shell on an inner portion of which is provided a more durable composition of a silver alloy by pressing or casting to achieve longer lifetime under arcing conditions in air or oxygen while minimizing the cost of materials and fabrication.

Abstract: Excavatged landfill material is treated in a plasma fired cupola in a process wherein hazardous material such as PCB's are volatilized and consumed in an afterburner above the cupola and hazardous materials containing heavy metals are fixed in vitreous material made molten within the cupola and resulting in a non-leachable solid product.

Abstract: This invention relates to an electric arc heater process and apparatus for the essentially complete decomposition of hazardous materials including polychlorinated biphenyls. Finely divided liquid or gaseous hazardous material is injected into a primary gas stream which has been superheated in an electric arc heater. The mixture is directed into a primary reactor for complete decomposition with dwell times in the reactor being in the order of 0.05 to 0.15 seconds. The decomposition products are neutralized with the gases being released to atmosphere and any remaining particulates being collected for ultimate disposal. Large solid hazardous material is first shredded then heated in a roaster or rotary kiln to vaporize the primary gas stream. A soaking reactor is provided where increased dwell times are required for the decomposition of thermally stable compounds which may be formed in the primary reactor. When these compounds are absent the soaking reactor can be by-passed.