Recovery method of lead in waste circuit board

Abstract

A recovery method of lead in a waste circuit board includes the steps as follows: first crushing the waste circuit board, the particle diameter ranging from 0.08mm to 1.2mm, and enabling metal materials (copper, soldering tin and the like) in the circuit board to be separated from non-metal materials in the circuit board; separating mixed materials obtained after crushing in high-voltage static mode, enabling metal parts to be separated from non-metal parts, and obtaining mixed metal enrichment bodies; performing lead evaporation in a vacuum furnace with mixed metal enrichment bodies containing lead serving as raw materials, and finally condensing lead steam on the condenser. Lead recovery can reach over 90%, and purity can reach over 99%. Therefore, lead is separated from mixed metal, tin can be enriched, simultaneously, purity of copper is improved, and mixed metal after vacuum separation can be continuously used in targeted purification separating in the next step. The recovery method of lead in the waste circuit board particularly has the advantages in the aspect of environment pollution decreasing, avoids secondary pollution of toxic heavy metal lead to the largest extent, and has the advantages of being low in cost, high in efficiency, free of pollution and the like.

Description

technical field [0001] The invention relates to waste circuit boards, in particular to a method for recovering lead in waste circuit boards. Background technique [0002] With the rapid development of the electronic information industry, a new type of industrial waste - electronic waste: including various waste computers, communication equipment, televisions, refrigerators, washing machines, and electronic instruments and meters eliminated by the unit. According to expert estimates, there are about 28 million sets of electrical appliances such as refrigerators, washing machines, computers, and air conditioners scrapped every year in my country, and the total amount of discarded electronic appliances reaches 1 million tons. [0003] In electronic waste, the metal content is as high as about 60%, while the rich ore metal content in nature is only 3-5%. Discarded circuit boards are one type of electronic waste, and the metals contained in them are dozens or even hundreds of ti...

AI Technical Summary

Problems solved by technology

But the main problem of existence is that the consumption of chemical agent is big, and the treatment of waste liquid will cause secondary pollution, document " present situation of domestic and foreign electronic waste and resource technology thereof " (Wei Jinxiu etc., " Journal of Donghua University " 2005 the 3rd period ) introduced the separation of mixed metals by electrolysis

However, harmful gases such as hydrogen fluoride, carbon monoxide, and sulfur dioxide are produced during the electrolysis process, and waste electrolyte seriously pollutes the environment.

[0005] More importantly, these methods mainly focus on extracting precious metals and rare metals from circuit boards. With the improvement of production level and production process, the content of precious metals and rare metals in circuit boards is relatively gradually reduced. Pollution incidents caused by heavy metals such as heavy metals occur from time to time, leading to lead pollution in water bodies, soil, and the atmosphere, which in turn causes blood lead in humans, especially children, to seriously exceed the standard

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