METHOD FOR RECOVERING METAL FROM TIN-BASED PLATED COPPER OR COPPER ALLOY STRIP, OR SCRAP THEREOF

摘要

PROBLEM TO BE SOLVED: To easily and highly efficiently melt and recover high purity Sn-based metal and Cu-Sn-based intermetallic compound individually, from a copper or copper alloy plate the surface of which has been subjected to a reflow Sn-based plating, or from scrap thereof without using exclusive peeling liquid.SOLUTION: Superheated steam at 230-400°C is jetted from a jetting nozzle at a jetting pressure of 0.3-2.0 MPa and at a jetting quantity of 1-20 kg/h for 5-180 sec under an atmosphere of 0.2-3.0% oxygen concentration, onto the whole surface area of an Sn-based metallic surface layer of a copper or copper alloy strip or scrap thereof, the copper or copper alloy strip being provided with a Cu-Sn-based intermetallic compound layer having a thickness of 0.1-2.0 m and the Sn-based metallic surface layer having a thickness of 0.1-10.0, thereby melting and recovering the Sn-based metal. Thereafter, onto the whole surface area of the Cu-Sn-based intermetallic compound layer, superheated steam at 400°C to 600°C, is jetted from the jetting nozzle under the atmosphere of the above oxygen concentration, and at the above jetting pressure and jetting quantity to melt and recover the Cu-Sn-based intermetallic compound.