Method for reclaiming hydrochloric acid and metal copper from printed circuit acidic etching waste liquid

Abstract

The invention relates to a method to recycle hydrochloric acid and copper from acidic waste etching liquid of printing circuit, comprising the equipment: a heater, an evaporator, a stuffing tower, a separator, a condenser, a liquid receiving tank, an extraction box, a corrosion resistant pump, a flux meter, an electrobath, a commutator, an anode plate and conductive copper strips, etc. The technique steps are: 1. Recycling hydrochloric acid through a distillation method; 2. extracting and repairing copper sulfate through an extraction method. 3. recycling copper through an electrolysis method. The recovery rate of hydrochloric acid of the invention is as high as 80 percent, copper as high as 99.5 percents, which not only is beneficial to environment protection but also can recycle hydrochloric acid and electrolyze copper. The recycled hydrochloric acid can be reused in PCB production line by adding a little etching additive, which realizes the circulation economy model of decreasing pollution and recycling waste in the industry at the same time.

Description

Technical field: [0001] The invention relates to a recycling method for acidic etching waste liquid in the production process of printed circuit boards, in particular to a method for recycling hydrochloric acid and electrolytic metal copper in the acidic etching waste liquid. Background technique: [0002] In the production process of printed circuit boards, acid and alkaline etching processes are usually used to produce circuit boards. These enterprises produce a large amount of corrosion waste liquid every year. Acid etching liquids include hydrochloric acid, hydrochloric acid + sodium chlorate, hydrochloric acid + hydrogen peroxide and other processes. The main components CuCl 2 and HCl, the copper content of which can reach 130g / L, which is a hazardous waste. At present, there are several ways to recover copper from waste etching solution: [0003] 1. Replacement method; this method is to put pig iron powder into the acidic etching waste liquid, and use the activity of...

AI Technical Summary

Problems solved by technology

Etching solution can not be regenerated, resulting in waste

[0004] 2. Dilution and neutralization extraction method: This method is to put a large amount of NaOH into the etching waste liquid of the acid etching solution such as hydrochloric acid, hydrochloric acid+sodium chlorate, hydrochloric acid+hydrogen peroxide, etc., and extract copper when it is neutralized to PH=2-3. Although this method does not produce chlorine gas, it will produce a large amount of waste water, which also contains a large amount of NaCl, and its etching solution is difficult to regenerate and recycle, resulting in waste

[0005] 3. Diaphragm electrolysis method: This method uses active Cl - The anode performs diaphragm electrolysis on the acidic etching waste liquid, but the metal copper recovered by electrolysis is in the form of powder, and a large amount of hydrogen and chlorine gas are generated when the hydrochloric acid solution is electrolyzed, which is extremely dangerous, and the anode is consumed very quickly, and the production and operation costs are extremely high

[0006] 4. Sulfuric acid extraction distillation method: This method is to add sulfuric acid to the acidic etching waste liquid for high-temperature distillation, use the different boiling points of sulfuric acid and hydrochloric acid to distill, separate and recover HCl and produce copper sulfate. This method needs to add a large amount of sulfuric acid to replace CuCl with copper sulfate. , since copper sulfate is a chemical product, special chemical production qualifications are required, and circuit board manufacturers do not have production qualifications