SU1700099A1 - Method of regeneration of spent copper chloride base pickling solutions - Google Patents

Abstract

This invention relates to the regeneration of spent pickling solutions on a light copper copper. The purpose of the invention is to ensure the possibility of regeneration of aluminum after etching tin coatings. The proposed method includes cemeggsts: tin metal, electrochemical osax; some of them using a membrane ccpiooo eksn and dissolution of the obtained copper powder by blowing air through a pre-heated solution, after electrolytic treatment, Implementation (by cementation on tin gives rise to the heat, after heating the electrolytic treatment, Realization (cementation on the tin gives rise to the solution). etched metal is more electronegative than the main. 2 table

Description

This invention relates to the regeneration of spent pickling solutions.

The aim of the invention is to enable the solution to be regenerated after etching tin coatings.

P r i m e r. In an etching solution containing initially 130 ml / l of hydrochloric acid (density 1.19 g / sig), 3 g / l of chlorine copper (in terms of metal) and 10 g / l of tin salt (in terms of metal), removed Tin coating from printed circuit boards. After increasing the concentration of tin to 12-13 g / l, the solution is subjected to regeneration. The copper is removed from the solution by mixing it in a container with tin sheets suspended in it. After complete removal of copper (determined by qualitative reaction with potassium ferrocyanide), the solution is drained from the copper precipitate and sent to the cathode space

electrolytic cell, the anodic space of which is filled with 30% sulfuric acid solution is separated from the cathode chion-membrane by an erolmz at a density of 1-2 A / dm until the concentration of tin is reduced to 8-9 g / l. Tin from cathodes is used to make anodes for electroplating baths and sheets for carburizing The solution after electrolysis with previously extracted copper powder containing up to 30% oioea trapped in it during carburization, and air is blown through it to completely dissolve the powder and oxidize the metal ions. The end of the process is fixed by changing the color of the solution - the color of the colorless becomes green-blue. More precisely, the MGJKHO process is defined by the magnitude of the redox potential. Potential of the electrode pair,

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consisting of platinum and glass electrodes, in a fully oxidized solution is 0.10 V.

The balance of tin in the process of regeneration of the etching solution is presented in table 1.

Kick can be seen from Table 1, regeneration of the solution passes with almost no loss of tin. In this case, a significant part of tin (2.7) is returned to the solution during the oxidation of the suspension, which eliminates the discharge of the solution, i.e. get an environmental effect.

The herbal ability of the solution does not deteriorate after regeneration, which is confirmed by the data in Table. 2 according to the determination of the duration of etching of tin coatings in the regenerated solution in comparison with the freshly prepared one.

From Table 2, it can be seen that the herbal ability of the solution does not deteriorate after regeneration.

In the proposed method, ions of the base metal — copper — are removed by cementation in order to preserve it for subsequent return to solution at the final stage of regeneration after removal of tin from the solution. In this case, the cementation is carried out on tin, which makes it possible to exclude other metals from the solution besides those already present in it. Then the etched metal - tin is removed from the solution by electrolysis, after which the previously removed copper is returned to the solution, its solution is blown up with air, and the solution restores the etching properties, i.e. the regeneration process is complete.

Claims (1)

In the proposed method, it is possible to regenerate the solution, in which the etched metal is more electronegative than the main one. Formula of isobring A method of regenerating spent pickling solutions based on chlorine copper, including copper cementation and subsequent electrochemical treatment of the solution using a katon-exchange membrane, characterized in that, in order to allow the solution to be regenerated after etching of the gold coatings, copper cementation is carried out The tin and the resulting copper powder are dissolved by blowing air through the regenerated solution after its electrochemical treatment. The number of regenerations Table 1 .Table 2 Duration of removal of tin coating with a thickness of 10 µm, s