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Two-step debromination method for waste printed circuit board

A technology for waste printed circuits and printed circuit boards, which is applied in the field of two-step debromination of waste printed circuit boards, can solve the problems of unfavorable pyrolysis oil resource utilization, high cost, expensive catalysts, etc., so as to solve the bottleneck of recycling and save electricity. , the effect of increasing the feasibility

Inactive Publication Date: 2014-06-11
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In the above-mentioned pyrolysis debromination method of waste printed circuit boards, the selected catalyst is relatively expensive and the cost is high, and the obtained pyrolysis oil still contains a relatively high content of bromine, which is not conducive to the further resource utilization of the pyrolysis oil

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] (1) Raw material pretreatment

[0031] Remove the electronic components on the waste printed circuit board, and then use a shear to cut the whole piece of waste printed circuit board into 5 × 5cm sheets, and store them as raw materials.

[0032] (2) One-step debromination method

[0033] Add the 5×5cm waste printed circuit board and 150g of FeOOH obtained in step (1) into the fixed-bed pyrolysis reactor at a mass ratio of 1:0.1. The heating rate of ℃ / min is raised to 500 ℃, the constant temperature pyrolysis reaction is 1.5 hours, and naturally cooled to room temperature, the low-bromine liquid products and solid products produced by pyrolysis are collected, and the gas products are absorbed through the NaOH solution absorption tank, calculated by mass percentage, The bromine content in the obtained low-bromine liquid product is 5%.

[0034] (3) Two-step debromination method

[0035] In the low-bromine liquid product obtained in step (2), add 30 ml of an alcoho...

Embodiment 2

[0037] With embodiment 1, difference is that in step (2) additive is Fe 3 o 4 , according to waste printed circuit board and Fe 3 o 4 The mass ratio is 1: 0.02, and the constant temperature pyrolysis reaction is 1 hour, and the bromine content in the obtained low-bromine liquid product is 7% by mass percentage. The catalyst in step (3) is palladium carbon.

Embodiment 3

[0039] Same as Example 1, the difference is that the additive in step (2) is diatomite, the mass ratio of waste printed circuit board and diatomite is 1: 0.05, constant temperature pyrolysis reaction is 1 hour, and the obtained The bromine content in the low bromine liquid product is 8%. The catalyst in step (3) is HZSM-5 molecular sieve.

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PUM

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Abstract

The invention discloses a two-step debromination method for a waste printed circuit board. The method comprises the following steps: adding the waste printed circuit board and an additive into a fixed bed pyrolysis reactor; raising the temperature to 450-600 DEG C in a vacuum atmosphere and carrying out a constant-temperature pyrolysis reaction; naturally cooling to a room temperature and collecting a low-bromine liquid product and a solid product which are generated by pyrolysis; adding the collected low-bromine liquid product into an alcohol alkali solution; adjusting the pH value to 11 by sodium hydroxide or potassium hydroxide; adding a catalyst and controlling a reaction temperature at 50+ / -5 DEG C; and magnetically agitating for reacting for 3 hours. Compared with other debromination manners, the two-step debromination method has the advantages that bromine can be completely removed to obtain purified bromine-free pyrolysis oil which can be directly used for extracting chemical raw materials or can be used as fuel oil, and the bottleneck of full component recycling through vacuum pyrolysis of the waste printed circuit board is overcome.

Description

technical field [0001] The invention relates to a two-step debromination method for waste printed circuit boards, and belongs to the technical field of harmless and resourceful utilization of electronic waste. Background technique [0002] At present, the disposal of waste printed circuit boards (WPCB) is mainly through physical crushing and recycling of metals, while the main treatment methods for WPCB plastics are landfill, simple physical regeneration and incineration. However, due to the complex composition of WEEE plastics, it is difficult to identify and separate them. Impurities of various materials are mixed together, resulting in a significant decline in the performance of the material obtained by physical melting regeneration, and the value is not high. On the other hand, WPCB plastics generally contain halogen flame retardants, mainly brominated flame retardants. Brominated hydrocarbons and polybrominated aromatic hydrocarbons, especially dioxins and furans, are f...

Claims

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Application Information

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IPC IPC(8): B09B3/00C08J11/24C08J11/16
CPCY02W30/62Y02W30/82
Inventor 孙水裕李神勇刘敬勇钟胜宋卫锋戴文灿谢武明杨帆
Owner GUANGDONG UNIV OF TECH