Tin stripping liquid, method for removing tin-containing layer on base material and method for recycling simple substance tin

Abstract

The invention discloses a method for recycling simple substance tin. The method for recycling the simple substance tin comprises the steps that a tin-containing layer on a base material is removed byusing tin stripping liquid to obtain tin stripping waste liquid, wherein the tin stripping liquid comprises nitric acid with the concentration being 5 g / L-100 g / L, a complexing agent with the concentration being 70 g / L-640 g / L, a stabilizer with the concentration being 10 g / L-150 g / L and an antioxidant with the concentration being 0.5 g / L-25 g / L, wherein the stabilizer comprises at least one of carboxylic acid compounds, urea compounds and amino acids; an extractant and the tin stripping waste liquid are mixed to make the nitric acid in the tin stripping waste liquid enter the extractant, andseparation is conducted to obtain the extracted tin stripping waste liquid and extraction liquid containing the extractant and the nitric acid; and diaphragm electrolysis is conducted on the extractedtin stripping waste liquid to obtain the simple substance tin. The method for recycling the simple substance tin has the advantages of regenerating and recycling of the waste liquid and zero discharge of the waste liquid.

Description

technical field [0001] The invention relates to a method for recovering elemental tin, in particular to a method for recovering elemental tin from tin-stripping waste liquid by using diaphragm electrolysis. Background technique [0002] Printed Circuit Board (PCB) is one of the important parts of the electronics industry and is the support of electronic components. Generally, the process of manufacturing printed circuit boards includes using a tin stripping solution to remove the tin-containing layer on the circuit board, thereby generating a large amount of tin stripping waste solution. At present, tin stripping solutions can be divided into three types according to their main components: fluoride type, strong alkali type and nitric acid type. The fluoride-type tin stripping solution has basically been eliminated due to its poor environmental indicators (fluoride is highly volatile and extremely polluting) and its technical and economic indicators are poor. Due to its gen...

AI Technical Summary

Problems solved by technology

This not only produces a large amount of waste residue, insufficient utilization of resources, but also high processing costs

In recent years, there have been distillation recovery methods, acid precipitant treatment methods, etc., but these methods will generate a large amount of other waste liquids, causing secondary pollution, and the process is complicated, the conditions are strictly controlled, and the treatment cost is high.

Images