Method for recovering copper from acid etching liquid and special device for method

The invention relates to a method for recovering copper from an acid etching liquid and a special device for the method, belonging to the fields of resourceful treatment of waste liquid and recovery of nonferrous metal. The special device comprises an electrolytic bath and an anode chamber arranged in the electrolytic bath, wherein a cation exchange member is arranged in the anode chamber; a dilute sulfuric acid solution is accommodated in the anode chamber; an iridic oxide coating titanium plate is used as an anode electrolytic plate; the acid etching liquid is accommodated in the electrolytic bath; a coating-free titanium plate is used as a cathode electrolytic plate; the cathode electrolytic plate and the anode electrolytic plate are respectively inserted into the electrolytic bath and the anode chamber and are connected with a negative electrode and a positive electrode of a direct-current and voltage-stabilizing power supply; the space between the cathode electrolytic plate and the anode electrolytic plate is 50-70mm; and the voltage of the direct-current and voltage-stabilizing power supply is 3.6-4.2V. The electrochemical reaction mechanism of the method for recovering the copper is as follows: anode: 2 obtains 2e to generate H2O and 1/2O2 (gas); and cathode: Cu loses 2e to generate Cu and Cu loses e to generate Cu. The method has the advantages of simple process, low cost, no pollution, high purity of recovered metallic copper and high electrolysis efficiency.