What is the principle of electrolytic copper recovery?
Jul 20, 2022
Copper is a commonly used non-ferrous metal. Copper is widely used in the electric power industry, electronic industry, and daily life. Extracting copper from ore is costly and requires a long process. Extracting copper from copper-containing waste liquid and waste (including plating and mixed materials) has less pollution and high efficiency, and can purify other raw materials at the same time, with a win-win effect.
The copper in the waste (liquid) is recovered by the leaching-electrolysis method, which has the advantages of fast speed, high speed, recyclable liquid medicine, and automatic operation. At the same time, this method of metal recovery is in line with the world development trend of environmental protection and resource recycling. It is divided by the acidity and alkalinity of the leaching solution. The copper leaching solution can be divided into two types: acid leaching solution and ammonia leaching solution.
Acid leachate has the following types and applications:
1. Ferric chloride-hydrochloric acid immersion copper solution is more commonly used for circuit board etching.
2. Copper chloride hydrochloric acid immersion copper solution is more commonly used for etching circuit boards.
3. Sulfuric acid hydrogen peroxide immersion copper solution is often used for micro-etching of copper surface in circuit board manufacturing and recovery of copper-containing circuit board scrap copper.
Ammonium salt-ammonia leaching solution is more commonly used for the separation of copper in copper-clad steel (aluminum).
A: The principle of leaching in acid solution-electrolysis recovery plating leaching and electrolysis.
1. Ferric chloride-hydrochloric acid system
Leaching copper FeCl+Cu--→FeCl2+CuCL
Electrolytic extraction of copper Cu2+2e--→Cu (cathode)
Fe2+-e--→Fe3+ (anode)
2. Copper chloride----hydrochloric acid system
Leached copper CuCl2+Cu--→CuCl CuCl+HCl-_→HCuCl
Electrolytic extraction of copper Cu*+e--→Cu (cathode)
Cu-e--→Cu+ (anode)
3. Sulfuric acid-hydrogen peroxide system
Leaching copper H2SO+O2+Cu--→CuSO
Electrolysis Cu2++2e--→Cu (cathode)
2HO-4e--→O2+4H+ (anode)
B. Ammonia system
Leached copper Cu+[Cu(NH3)4]2++4NH--→2[Cu(NH)4]+
Oxidation 2【Cu(NH)4】++1/2+H2O-→
→2【Cu(NH3)4】2+ +20H
Since the potential of copper is negative in ammonia solution, copper can be oxidized in air. In an acidic solution, the potential of copper is positive, and only in the presence of an oxidant can copper dissolve. Therefore, in terms of technology, the first consideration is to extract copper from an acidic solution.
