Treatment method of waste liquid after cleaning copper plated layer of printed circuit board

Abstract

The invention relates to a treatment method of waste liquid after cleaning a copper plated layer of a printed circuit board. The treatment method comprises the following steps: adding zinc powder of 50-80 meshes and percentage by weight of 99.9% into the waste liquid obtained after cleaning the copper plated layer of the printed circuit board for reaction, wherein the adding amount of the zinc powder is 260-310g per liter of the waste liquid and the reaction temperature is 70-80 DEG C; performing electromagnetic stirring reaction for 4-4.5 hours while adding the zinc powder to get a zinc chloride solution and copper powder; driving the solution after the reaction into a settling tank for settling for 20-24 hours, performing precipitation separation on supernatant fluid of zinc chloride from copper powder at the bottom layer, performing evaporation and crystallization on the supernatant fluid to obtain anhydrous zinc dichloride, filtering and washing the copper powder separated by precipitation, and drying for 20-24 hours at the temperature of 120-150 DEG C under the protection of inert gas to obtain a copper powder product. The anhydrous zinc dichloride obtained by adopting the treatment method disclosed by the invention is tested to completely conform to indexes of industrial stage II anhydrous zinc dichloride; and the copper amount in the obtained copper powder is not less than 98%, and the process is simple and significant in recovery value.

Description

technical field [0001] The invention relates to a treatment method for copper-containing waste liquid, in particular to a treatment method for waste liquid produced by cleaning remaining copper plating in the preparation of printed circuit boards. Background technique [0002] The copper-layer plastic composite board is the raw material of the printed circuit integrated board. During the preparation process, the excess copper plating is cleaned off, and the remaining copper plating and plastic board form the printed circuit integrated board required by the design. The copper-containing acid waste liquid produced by the cleaned copper plating layer contains a large amount of metallic copper components. It is currently a technical difficulty to economically and effectively recover valuable metal copper without any excessive discharge to the environment. [0003] The waste liquid produced by cleaning the remaining copper plating layer with hydrochloric acid in the preparation o...

AI Technical Summary

Problems solved by technology

[0003] The waste liquid produced by cleaning the remaining copper plating layer with hydrochloric acid in the preparation of printed circuit integrated boards contains about 122.53g / l of copper ions, about 266.06g / L of chloride ions, and about 0.83g / L of ferrous ions. Corrosion is very strong. Titanium plates and stainless steels with strong corrosion resistance in the conventional electrowinning method are severely corroded and cannot be used. Therefore, it is necessary to find an unconventional process that can overcome chloride ion erosion and extract metallic copper. There is no relevant information at home and abroad