Method for treating acidic copper-containing waste liquid

Abstract

The invention relates to the field of acidic copper-containing waste liquid treatment and provides a method for treating an acidic copper-containing waste liquid. The method includes the steps that an oxidizing agent is added into the acidic copper-containing waste liquid to enable cupric ions to be converted to bivalence, so that a mother liquid is obtained, and the concentration of cuprous ions in the mother liquid is smaller than or equal to 0.5g / L; a part of copper in the solution is separated from the mother liquid in a mode of a cupric compound crystal substance to obtain a separating medium, and the soluble copper volume of the separating medium is released; and the separating medium is subjected to component adjusting and purifying treatment to enable the separating medium to recover to the condition after a copper acidic etching solution is prepared and before the copper acidic etching solution is used, an acidic etching regenerated solution is obtained to be used in a recycling mode.

Description

technical field [0001] The invention belongs to the field of treatment of acidic copper-containing waste liquid, and in particular relates to a treatment method for copper etching waste liquid produced in the production of printed circuit boards with high copper content. Background technique [0002] Printed circuit board (PCB) manufacturing, metal cleaning and surface treatment, inorganic salt production, electroplating, sign making, copper hydrometallurgy and other industries will use copper-containing solutions and / or produce copper-containing waste liquids. The specific copper content is between 0.2-200 g / L, which can be divided into two types: alkaline system and acidic system, as shown in USP3999564 and USP4130454. The former is a copper solution containing ammonia, ammonium salt and chloride ions, which is commonly known as copper Ammonia solution, also known as alkaline etching solution; the latter, such as copper solution containing chloride ions and hydrochloric ac...

AI Technical Summary

Problems solved by technology

However, technical personnel familiar with the PCB industry know that the copper etching solution has high technical requirements when working, and the quality index of the etching process of the etching solution recycling technology based on the recovery of copper and copper oxide cannot be guaranteed, because during the electrolysis process In the regenerative etching solution, new substances that have a negative impact on the etching quality (such as side etching factor) will be produced and accumulated continuously, and the cracking and dissolution of the resist layer (such as dry film, film formed after drying the wet film, etc.) substances can also pollute the copper etching solution, so the number of recycling times of the above-mentioned etching solution recycling technology is very limited, and the quality effect of its recycling use is also uncertain; in addition, copper is recovered based on electrochemical methods. There is also a fatal weakness of the current etching solution recycling technology: it produces chlorine gas (escaping) during the production process, and the phenomenon of chlorine gas produced in the recovery of copper from acidic copper etching solution is especially serious, which makes the safety hazards of the production process very serious. , The equipment is severely corroded, and has serious hazards to the relevant work site and its surrounding environment and the health of the staff