Abstract: A method for detoxifying spent CCA (copper, chromium, arsenic) treated wood, from which CCA is efficiently removed from the wood, allowing both the CCA and the wood to be reused has been developed. The method comprises the steps of (1) microwave-enhanced acid extraction of CCA, (2) separation of the acid-containing CCA solution from the wood, (3) separation/precipitation of CCA from the acid extract, (4) recovery and regeneration of CCA-bearing precipitant for reuse in the wood preservation industry, (5) recycling recovered acid solution, (6) microwave-assisted liquefaction of the extracted wood, and (7) use of detoxified liquefied wood to form polymeric materials such as polyurethanes and phenolic resin adhesives. The recovered CCA may be used to treat wood. The recovered acids may be used to extract CCA from CCA-treated wood, and the liquefied wood may be used as phenolic or polyurethane resins.

Abstract: A chemical process for detoxifying spent CCA (copper, chrome, arsenic)—treated wood, from which CCA and detoxified wood are recovered for recycling comprising the steps of (a) treating CCA-treated wood in the presence of a liquefying reagent such as an organic solvent at 100–250° C. with or without ferrous ions to form liquefied CCA-treated wood (b) adding water or an aqueous solution of an organic solvent to the liquefied CCA-treated wood with stirring to obtain an aqueous solution of liquefied CCA-treated wood (c) adding complexing or precipitating agents, such as phosphoric acid or calcium hydroxide to the aqueous solution of step (b) thereby precipitating insoluble heavy metal complexes or precipitates and forming a solution of detoxified CCA-treated wood (d) separating said heavy metal complexes or precipitates from the solution of detoxified liquefied CCA-treated wood and (e) isolating chromated copper arsenate from said heavy metal complex or precipitate.

Abstract: A chemical process for detoxifying spent CCA (copper, chrome, arsenic)—treated wood, from which CCA and detoxified wood are recovered for recycling comprising the steps of (a) treating CCA-treated wood in the presence of a liquefying reagent such as an organic solvent at 100-250° C. with or without ferrous ions to form liquefied CCA-treated wood (b) adding water or an aqueous solution of an organic solvent to the liquefied CCA-treated wood with stirring to obtain an aqueous solution of liquefied CCA-treated wood (c) adding complexing or precipitating agents, such as phosphoric acid or calcium hydroxide to the aqueous solution of step (b) thereby precipitating insoluble heavy metal complexes or precipitates and forming a solution of detoxified CCA-treated wood (d) separating said heavy metal complexes or precipitates from the solution of detoxified liquefied CCA-treated wood and (e) isolating chromated copper arsenate from said heavy metal complex or precipitate.

Abstract: A method of forming particle board characterized by the use of an adhesive comprising a polyisocyanate and a phenolic adhesive. Enhanced adhesive characteristics and other advantages are associated with the method in which the polyisocyanate is added to the wood particles, etc. prior to application of the phenolic adhesive.