METHOD AND APPARATUS FOR PYROLYZING METAL-MIXED PLASTIC WASTE AND RECOVERING METAL

PROBLEM TO BE SOLVED: To provide a method for pyrolyzing metal-mixed plastic waste as it is in a glass-fused liquid and recovering metals precipitated in the glass-fused liquid, metals dissolved in the glass-fused liquid, metals volatilized/dispersed in a pyrolysis gas and metals dissolved in cooling water. SOLUTION: The metal-mixed plastic waste is pyrolyzed in a pyrolysis apparatus 21 at stable temperature so that the calorie to be absorbed when the metal-mixed plastic waste is pyrolyzed is complemented with the calorie to be generated when plastics are burned and the calorie to be generated when the combustion gas is reacted with constituent substances of the glass-fused liquid and the calorie retained in the pyrolysis apparatus is adjusted by the volume of the glass-fused liquid. Metals precipitated in the glass-fused liquid are recovered in a precipitated metal recovery apparatus 10 together with the glass-fused liquid. Metals dissolved in the glass-fused liquid are precipitated on a DC electrode and the precipitated metals are recovered in a water-cooled dissolved metal recovery apparatus 18 together with the glass-fused liquid. Metals volatilized/dispersed in the pyrolysis gas are solidified/recovered by cooling the metal-containing pyrolysis gas with water in cooling tanks 23-27. Active substances contained in the pyrolysis gas are oxidized/burned to obtain stable gas and the stable gas is discharged. Metals dissolved in cooling water are neutralized in a neutralization tank 32 and recovered as precipitates and the water is recovered and reused. COPYRIGHT: (C)2010,JPO&INPIT