Method for recovering brownification waste liquid

Abstract

The invention provides a method for recovering brownification waste liquid. The method comprises the following steps: complexation and impurity removal: adding alkaline substances into the brownification waste liquid, adjusting the pH value to be 0-2, introducing SO2 gas to react to generate a precipitate, and filtering to obtain the precipitate and first filtrate; metal copper reduction: adding deionized water into the precipitate, stirring and slurrying, adding an alkaline solution to adjust the pH value to obtain a neutral solution, then adding hydrazine hydrate, fully stirring, reacting to generate copper sponge and nitrogen, and filtering to obtain the copper sponge and second filtrate; and preparation of regenerated brownification liquid: adding an additive into the second filtrate to obtain additive sub-liquid, and adding sulfuric acid, hydrogen peroxide and a stabilizer into the additive sub-liquid to obtain the regenerated brownification liquid. By means of the method, the problem that a large amount of brownification waste liquid in a PCB factory needs to be treated in an outsourced mode can be solved, meanwhile, the purpose of recycling part of the waste liquid can be achieved, and implementation of circular economy is facilitated.

Description

technical field [0001] The invention relates to the technical field of waste liquid treatment, in particular to a recovery method of browning waste liquid. Background technique [0002] In the manufacturing process of PCB (Printed circuit board, printed circuit board) multilayer board, the browning process of inner layer board is more and more widely used. The browning treatment process is a chemical copper corrosion reaction process. When the amount of copper dissolved in the browning solution exceeds the standard and the browning effect fails, browning waste liquid is produced. The main components of browning waste liquid are high-concentration sulfuric acid, hydrogen peroxide, copper microetching agent, stabilizer and a large amount of copper ions and other complex compounds and reaction products. Browning waste liquid contains a large amount of harmful substances, which can be directly Emissions will destroy the ecological balance and endanger human health. And these w...

AI Technical Summary

Problems solved by technology

However, because the browning waste liquid has strong film-forming ability, strong complexing ability, stable existence under strong acidic and weak oxidant conditions and is not easy to be oxidized and degraded, the above treatment methods have their own defects.

In the process of electrolysis and electroosmosis, the browning waste liquid is easy to form a film on the surface of the electrode and the ion exchange membrane, and the treatment efficiency is low; in the extraction and resin adsorption treatment, the organic matter and copper ions cannot be separated well; after adding NaOH, Na 2 In the sedimentation treatment of browning waste liquid by reagents such as S, the purity of the precipitate produced is low and difficult to separate, which is not an ideal copper precipitation method; the cost of oxidation degradation method is too high; distillation method will decompose part of the low boiling point additives or some additives in the place Interaction under controlled temperature, resulting in the loss of some active ingredients in the browning solution and the imbalance of the effective component distribution of the original browning solution; the use of chemical precipitation method, that is, the acid-base neutralization method, this method is simple in process and consumes a lot of alkali , waste water is difficult to discharge, and the degree of copper resource utilization is low; because the content of inorganic salts such as copper sulfate in the waste browning liquid is too high, which is not conducive to the growth and reproduction of microorganisms, it is not suitable to use biological degradation

Images