Method and device for recycling acidic etching waste solution through progressive electrolysis

Abstract

Disclosed is a method and device for recycling an acidic etching waste solution through progressive electrolysis. The method includes: introducing at least one electrolytic cell A, where the electrolytic cell A is divided into an anode chamber and a cathode chamber; during an electrolysis operation, a cathode electrolyte of the electrolytic cell A includes the acidic etching waste solution; and introducing at least one electrolytic cell B, where the electrolytic cell B is divided into an anode chamber and a cathode chamber; the cathode electrolyte of the electrolytic cell B includes a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell A or a mixed solution of the cathode electrolyte undergoing the electrolytic treatment with the acidic etching waste solution. With the present disclosure, PCB manufacturers can avoid the introduction of new impurities and reduce the electrolysis energy consumption during an electrolytic copper recovery process.

What is claimed is: 
     
         1 . A method for recycling an acidic etching waste solution from PCB production through progressive electrolysis, comprising the following steps:
 step  1 , introducing at least one electrolytic cell A, wherein the electrolytic cell A is divided with an electrolytic cell separator into an anode chamber and a cathode chamber; during an electrolysis operation, the anode chamber and the cathode chamber of the electrolytic cell A are provided with an electrolytic anode and an electrolytic cathode respectively to allow electrolysis for an anode electrolyte and a cathode electrolyte of the electrolytic cell A respectively; and the cathode electrolyte of the electrolytic cell A comprises the acidic etching waste solution;   step  2 , introducing at least one electrolytic cell B to conduct the progressive electrolysis for copper recovery, wherein the electrolytic cell B is divided into an anode chamber and a cathode chamber; during an electrolysis operation, the anode chamber and the cathode chamber of the electrolytic cell B are provided with an electrolytic anode and an electrolytic cathode respectively to allow electrolysis for an anode electrolyte and a cathode electrolyte of the electrolytic cell B respectively, such that an electrochemical reaction of reducing a copper ion into metallic copper occurs at the electrolytic cathode of the electrolytic cell B; and the cathode electrolyte of the electrolytic cell B comprises a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell A or a mixed solution of the cathode electrolyte undergoing the electrolytic treatment from the electrolytic cell A with the acidic etching waste solution; and   step  3 , when an amount of metallic copper deposited at the electrolytic cathode of the electrolytic cell B due to the electrochemical reaction reaches a preset target electroprecipitated amount, taking the electrolytic cathode of the electrolytic cell B out from the electrolytic cell B.   
     
     
         2 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 1 , wherein the anode electrolyte of the electrolytic cell A comprises at least one selected from the group consisting of a working etching solution, an etching waste solution, and a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B; and the anode electrolyte of the electrolytic cell B comprises at least one selected from the group consisting of a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B, a working etching solution, and an etching waste solution. 
     
     
         3 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 1 , wherein according to an oxidation-reduction potential (ORP) value of the cathode electrolyte in the cathode chamber of the electrolytic cell A and process requirements, an output current of an electrolytic power supply for the electrolytic cell A is adjusted or the electrolytic power supply for the electrolytic cell A is powered on/off, and/or a solution comprising the acidic etching waste solution is supplemented to the cathode chamber of the electrolytic cell A to maintain a concentration of a copper-etching agent in the cathode electrolyte of the electrolytic cell A, such that only a small amount of metallic copper or even no metallic copper is electroprecipitated on the electrolytic cathode of the electrolytic cell A, and an electrochemical reduction reaction mainly occurs at the electrolytic cathode of the electrolytic cell A to reduce a concentration of the copper-etching agent CuCl 2  or CuCl 2 +FeCl 3  in the cathode electrolyte of the electrolytic cell A or even eliminate the copper-etching ability of the cathode electrolyte. 
     
     
         4 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 1 , wherein in an electrolysis process, an ORP value of the cathode electrolyte of the electrolytic cell A is controlled at 200 mV to 580 mV, that is, an ORP value range is controlled at 200 mV to 580 mV by externally adding an etching waste solution. 
     
     
         5 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 1 , wherein at least one electrolytic cell C is additionally provided after the electrolytic cell B; the electrolytic cell C is divided into an anode chamber and a cathode chamber; during an electrolysis operation, the anode chamber and the cathode chamber of the electrolytic cell C are provided with an electrolytic anode and an electrolytic cathode respectively to allow electrolysis for an anode electrolyte and a cathode electrolyte of the electrolytic cell C respectively; the anode electrolyte of the electrolytic cell C comprises at least one selected from the group consisting of an acidic working etching solution, a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B, and a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell C, or, the anode electrolyte of the electrolytic cell C further comprises a etching waste solution; and the cathode electrolyte of the electrolytic cell C comprises a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B, or, the cathode electrolyte of the electrolytic cell C further comprises the cathode electrolyte of the electrolytic cell A and/or an etching waste solution. 
     
     
         6 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 5 , wherein copper ion concentrations in the cathode electrolyte of the electrolytic cell B and the cathode electrolyte of the electrolytic cell C are not less than 5 g/L. 
     
     
         7 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 5 , wherein a parameter value of at least one electrolyte in the method is detected, and on the basis of data measured on site, an output current of an electrolytic power supply for the electrolytic cell A and/or an electrolytic power supply for the electrolytic cell B and/or an electrolytic power supply for the electrolytic cell C is controlled and/or the electrolytic power supply for the electrolytic cell A and/or the electrolytic power supply for the electrolytic cell B and/or the electrolytic power supply for the electrolytic cell C is/are powered on/off, and/or addition of each material is controlled; and the parameter value comprises, but is not limited to, any one or more selected from the group consisting of an acidity value, a specific gravity value, an ORP value, a photoelectric colorimetric value, a liquid level, a temperature, a flow rate, and a harmful gas concentration. 
     
     
         8 . The method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 5 , wherein the anode electrolyte of the electrolytic cell A provided with the electrolytic cell separator and/or the anode electrolyte of the electrolytic cell B and/or the anode electrolyte of the electrolytic cell C is/are circularly mixed with a working etching solution on an etching production line, such that a copper-etching agent is supplemented to the working etching solution on the etching production line on line. 
     
     
         9 . A device to implement the method for recycling an acidic etching waste solution from PCB production through progressive electrolysis according to  claim 1 , comprising:
 at least one electrolytic cell A and at least one electrolytic cell B, wherein the electrolytic cell A is divided with an electrolytic cell separator into an anode chamber and a cathode chamber; the electrolytic cell B is divided into an anode chamber and a cathode chamber; an ORP meter is provided in the cathode chamber of the electrolytic cell A; the cathode chamber of the electrolytic cell A is connected with the cathode chamber of the electrolytic cell B through a liquid pipeline, such that a solution undergoing an electrolytic reaction in the cathode chamber of the electrolytic cell A is added to the cathode chamber of the electrolytic cell B to allow progressive electrolysis for copper recovery; the anode chamber of the electrolytic cell A and the cathode chamber of the electrolytic cell A are provided with an electrolytic anode and an electrolytic cathode respectively, and the electrolytic anode and the electrolytic cathode of the electrolytic cell A are connected with a positive electrode and a negative electrode of an electrolytic power supply for the electrolytic cell A respectively; and the anode chamber of the electrolytic cell B and the cathode chamber of the electrolytic cell B are provided with an electrolytic anode and an electrolytic cathode of the electrolytic cell B respectively, and the electrolytic anode and the electrolytic cathode of the electrolytic cell B are connected with a positive electrode and a negative electrode of an electrolytic power supply for the electrolytic cell B respectively.   
     
     
         10 . The device according to  claim 9 , wherein at least one electrolytic cell C is additionally provided after the electrolytic cell B; the electrolytic cell C is divided into an anode chamber and a cathode chamber; the cathode chamber of the electrolytic cell B is connected with the cathode chamber of the electrolytic cell C through a liquid pipeline, such that a solution undergoing an electrolytic treatment in the cathode chamber of the electrolytic cell B is added to the cathode chamber of the electrolytic cell C; the anode chamber of the electrolytic cell C and the cathode chamber of the electrolytic cell C are provided with an electrolytic anode and an electrolytic cathode respectively, and the electrolytic anode and the electrolytic cathode of the electrolytic cell C are connected with a positive electrode and a negative electrode of an electrolytic power supply for the electrolytic cell C respectively; during an electrolysis process, an anode electrolyte and a cathode electrolyte are provided in the anode chamber and the cathode chamber of the electrolytic cell C respectively; the anode electrolyte of the electrolytic cell C comprises at least one selected from the group consisting of a working etching solution, a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B, and a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell C, or, the anode electrolyte of the electrolytic cell C further comprises a etching waste solution; and the cathode electrolyte of the electrolytic cell C comprises a cathode electrolyte undergoing an electrolytic treatment from the electrolytic cell B, or, the cathode electrolyte of the electrolytic cell C further comprises the cathode electrolyte of the electrolytic cell A and/or an etching waste solution.