All-wet recovery process for waste circuit boards

Abstract

The invention discloses an all-wet recovery process for waste circuit boards. The all-wet recovery process comprises the following steps of crushing and reselecting the waste circuit boards to obtain multi-metal powder of the waste circuit boards; performing leaching on the multi-metal powder of the waste circuit boards with an acid solution with the concentration of 0.1-4 mol/L, and obtaining leach liquid and leach residues after solid-liquid separation; adding copper compounds and an acid solution with the concentration of 0.5-5 mol/L into the leach residues to replace and strip tin, and obtaining tin-bearing liquid and tin-separated residues after solid-liquid separation; adding an acid solution with the concentration of 0.2-6 mol/L into the tin-separated residues, leading oxygen and/or air into the mixture for an oxidation reaction, and obtaining copper-bearing liquid and precious metal residues after solid-liquid separation; and performing vortex electrodeposition on the copper-bearing liquid to obtain cathode copper. According to the all-wet recovery process for the waste circuit boards, the all-wet recovery process is provided for treating the waste circuit boards, so that directional separation, gathering and extraction of valuable metal in the process steps are achieved, and the problems of the dispersed moving of valuable metal elements of the waste circuit boards, the difficulty in subsequent separation and extraction and the like are solved.

Description

technical field [0001] The invention relates to the field of recycling waste resources, in particular to a full wet recycling process for waste circuit boards. Background technique [0002] In recent years, the production of electronic products has maintained a steady growth. According to data released by the Ministry of Industry and Information Technology of China, from January to November 2013, my country's electronic product manufacturing industry above designated size increased by 11.2%. However, the life cycle of electronic products is getting shorter and shorter with the continuous development of electronic technology. Since 1997, the average lifespan of computers and CPUs has dropped from 4 to 6 years to only 2 years. The rapid rise and replacement of new electronic products such as mobile phones has accelerated the elimination of electronic products. According to relevant reports from the European Union, the growth rate of electronic waste remained at about 11% fr...

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Problems solved by technology

[0003] The Chinese patent with the patent publication number CN101049955A discloses a method for preparing copper sulfate from copper in waste circuit boards, using dilute sulfuric acid, sodium chloride and copper sulfate system air oxidation to leaching copper in waste circuit boards at room temperature, filtering The resulting filtrate was evaporated and crystallized; sodium salt was introduced into the leaching system, and only the element behavior of copper was considered, and other metal elements were not studied

The U.S. patent with the patent publication number US20120318681A1 discloses a green cyanide-free wet process for recycling waste circuit boards. This process uses physical methods to separate metal and non-metal in waste circuit boards, and the obtained metal copper powder is cast into an anode After electrolytic purification, precious metals are recovered from anode slime; this method requires high physical separation, and it is difficult to meet the requirements of direct casting electrolysis through physical separation according to the current domestic research situation

The Chinese patent with the patent publication number CN101049955A discloses that waste circuit boards are placed in a vacuum container, heated and pyrolyzed, most of the pyrolysis volatiles are cooled and liquefied into liquid oil, and the other part enters the gas collector; during pyrolysis, centrifugal separation is used to The device separates the solder from the circuit board; the pyrolyzed circuit board substrate and electronic components are collected by classification for further separation and recycling; this method has high requirements for equipment temperature control and correspondingly high energy consumption

At the same time, the above-mentioned patents failed to consider the influence of other metal elements in the discarded circuit boards, and they were all concentrated on one or several metals, which would inevitably lead to the unknown direction of other metal elements and the comprehensive recovery of each element in industrial applications. Difficulty and other issues

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