Basic evaluation of sorting technologies for CCA treated wood waste

Two sorting technologies including an X-ray fluorescence technique and a Laser-induced breakdown spectroscopy (LIBS) technique were investigated for separating chromate copper arsenate (CCA) treated wood from other wood types in the wood waste stream. X-ray fluorescence was tested in the laboratory using a portably available X-ray fluorescence spectrometer. Operational parameters for continuous sorting using LIBS technology were established. These parameters concluded that chromate was the most sensitive metal for analysis, analysis time was less than 1 second per wood sample. LIBS technology shows considerable promise for continuous separation of large quantities of CCA treated wood from other wood types in the field using an on-line sorting system.