PROCESS FOR DECONTAMINATION OF CHROMATED COPPER ARSENATE TREATED WOOD

摘要

This invention relates to a chemical process of decontamination ofchromated copper arsenate (CCA) treated wood. This process includes: i) atleast one leaching step of metals from CCA-treated wood particles (solidscontent ranging from 20 to 200 g/L) with a diluted inorganic acid solution(0.05 to1 N) at a temperature lower than 100°C and for a period of time (0.5 to24 h)sufficient to adequately solubilize arsenic, chromium and copper; ii) theseparation of the wood particles from the acid solution; iii) at least onewashingstep of the wood particles in a solution in order to remove residual arsenic,chromium and copper; and iv) at least one treatment step for the recovery ofmetals from the acid leachates and washing waters. The decontaminated woodparticles and the metals extracted from the CCA-treated wood can be safelydisposed or recycled.