In the circuit board etching, electroplating and other industries, a large amount of copper-containing waste liquid is generated, and in particular, the amount of copper-containing ferric chloride etching waste liquid is large, and the copper recovery process is very complicated. The technology can separate the copper in the etching liquid in the form of cuprous oxide, fully utilize the resources, and has high efficiency, and is especially suitable for the ferric chloride etching waste liquid.
Cuprous oxide is a yellow to red solid that is mainly used in marine anti-corrosion coatings to prevent the attachment of aquatic organisms to the bottom of the ship. Other copper products such as cuprous chloride, copper sulfate, copper powder, etc. can be easily produced on the basis of cuprous oxide.
The cuprous ion is unstable in an aqueous solution, is easily oxidized by air to copper ions, and is easily reduced to pure copper by a reducing agent and an electric current, so that it is difficult to prepare high-quality cuprous oxide. Cuprous oxide has been commonly used in China for the reduction of inorganic or organic reducing agents. At present, the most advanced preparation method in the world is the method of electrolysis of pure copper in an alkaline solution. The advantage is that there is no waste, but the price of pure copper is high. The power consumption is large, and the condition control of product quality is very demanding.
The introduction of ferrous iron technology
The reduction of ferrous ions is much weaker than that of cuprous ions, so in general ferrous ions cannot reduce divalent copper ions to cuprous ions. After extensive experimentation and theoretical research, I found a special way to make the reaction of ferrous ions to reduce copper ions:
CuCl2+Fe2+→Cu2O↓+ FeCl3
Since ferrous ions are unlikely to continue to reduce cuprous copper to pure copper, contamination of the product is avoided. If the ferric chloride etching waste liquid is used as a raw material, the method directly separates the copper element in the presence of a large amount of ferric chloride, and the efficiency is high, and the remaining ferric chloride is partially reused, and partially used as a water purifying agent. Sold out.
Because the liquid phase reaction is used, the raw material is not required to be pure. In addition to using the ferric chloride etching solution as the raw material, the copper chloride etching solution, the sponge copper, the electrolytic copper, the electroplating waste liquid, the waste copper, the sponge copper, etc. can be used as the raw material. Good raw materials are much cheaper than existing methods.