Thermal treatment process for organically contaminated material

摘要

A thermal treatment process employs an indirectly fired rotary kiln in which matrix material contaminated with organic substances such as dioxins, PCBs, PAHs, fuel oils, and the like is heated as the material is advanced through the kiln to cause components of the organics to be released as vapor. Purge gas of low oxygen content is conducted through the kiln at a relatively low velocity of from about 0.5 ft./sec. to about 10 ft./sec. to gently sweep the vaporized components of the organic substances from the kiln and to minimize the entrainment of solid particulates, and to produce an off gas mixture including the vaporized components. The off gas is conditioned after removal from the kiln to render it acceptable for discharge to the atmosphere. The oxygen concentration in the kiln is maintained at a sufficiently low level to substantially prevent combustion of the vaporized organic components in the kiln.