Process for the thermal purification of contaminated materials

摘要

A process for the thermal purification of contaminated materials, preferably bulk solids rich in ash is described. It comprises driving off, in a first evaporation step, low-boiling point contaminants and water, and subjecting the gases/vapours driven off in this first evaporation step to secondary combustion in a combustion machine, in order to destroy the contaminants. The higher-boiling point contaminants are driven off in a second evaporation step by means of the contaminants being subjected, for the purpose of evaporation, to appropriate individual temperature profiles/final temperatures and residence times. The gases driven off in this second evaporation step then undergo secondary combustion in a directly fired thermal secondary combustion plant. One of the advantages of this process is that the amounts of material undergoing the second evaporation step are smaller than in known processes, thus requiring smaller investments to set up an installation suitable for carrying out the process. Furthermore, residual toxic pollution is reduced. Advantageous refinements of the process are described in which, in particular, energy utilisation is optimised by means of combined heat and power generation.