废弃线路板再资源化关键技术探讨

通过对目前国内外处理废弃线路板工艺技术的分析,指出废弃线路板再资源化的关键在于对其中的非金属组分的回收利用.结合废弃线路板资源的处理状况,针对不同的物料,提出相应的最佳处理办法分别为:改进的物理回收和真空热解.     

废弃印刷线路板综合回收技术评述

废弃的印刷线路板具有污染环境和潜在资源的双重特性.因此无论从环境保护,还是从资源利用上来讲,对废弃印刷线路板的综合回收再利用都具有极其重要的意义.本文主要介绍了当前废弃印刷线路板的各种综合回收技术.     

废旧印刷线路板的再资源化技术及新进展

废旧印刷线路板作为一种重要的二次资源,它的再资源化利用,符合当今对资源高效利用和环境保护的要求。本文对现阶段废旧印刷线路板的再资源化技术作了评述,着重介绍了再资源化废旧印刷线路板的超临界CO_2流体新技术,并将其与常规的资源化技术作了对比,指出了超临界CO_2流体在废旧印刷线路板再资源化方面的显著优势。     

微生物在废弃印刷线路板资源化中的应用研究进展

废弃印刷线路板（WPCBs）成分复杂,富含多种有色、稀贵金属,具有环境危害大、潜在价值高等特点。为使业界较全面地了解微生物在WPCBs资源化利用中的应用状况,推动该技术的发展,介绍了化能自养菌和异养菌浸出WPCBs中有价金属、微生物吸附法回收WPCBs浸出液中金属离子等3方面的发展,指出今后应加强高效菌种的选育、WPCBs微生物柱浸或搅拌浸出理论研究以及大颗粒WPCBs微生物搅拌反应器的研发等工作。     

降低线路板破碎过程中热解污染的资源化技术

随着电子产业的迅猛发展,印刷线路板(PCB)的报废量也大幅度上升。由于机械物理法对线路板的处理效率高、污染小,因而被广泛应用于工业生产。但实际生产设备多采用矿料破碎设备或稍作改进的设备,破碎完成后线路板粒度大,并没有实现完全解离,且破碎过程中易产生粉尘及少量有毒气体等污染物。针对这一技术现状和问题,自主开发了一套经济、绿色的线路板物理回收方法。该工艺采用两级破碎和三级分选实现了金属和非金属的高比例解离,并以水为介质降低破碎过程中局部的过高温度,解决了破碎中的热解污染和粉尘污染。     

碘化法从废弃印刷线路板中浸取金

研究用碘化法从废弃印刷线路板中浸取金的过程.结果表明,碘化法从废弃印刷线路板中浸取金的合理条件为:碘的质量分数为1.0%～1.2%,n(I2)∶n(I-)=1∶8～1∶10,助氧化剂双氧水的质量分数1%～2%,浸出时间4h,固液比为1∶10,浸出温度为常温(25℃),溶液pH值控制在中性.此时金浸出率可达95%.碘化法浸取金具有环保、高效、药剂易回收等优点.     

FXS废旧线路板回收处理成套设备

国家重点高新技术浙江丰利粉碎设备有限公司研发的国家专利产品、省级新产品，列入2005年浙江省重点技术创新项目计划，荣获国家技术创新基金支持。该设备采用先进的物理法回收工艺，所研制的设备创新性强，其资源化的处理工艺路线先进合理。该设备能对各类废旧印刷线路板及加工废料、废旧电器等进行机械粉碎回收处理，其金属回收率高，回收金属的纯度高达97％。     

废弃印刷线路板Pb,Cd和Cr的测定

研究用原子吸收分光光度计测定废弃印刷线路板中重金属元素Pb，Cd和Cr的含量。结果表明，方法灵敏、快速、准确、操作方便，实用性强。Pb，Cd和Cr的回收率在98．9％～103．6％之间，相对标准偏差RSD〈1．45％。     

硫代硫酸盐从废弃印刷线路板中浸金实验研究

硫代硫酸盐浸金的主要影响因素有: 浸取温度、反应时间、硫代硫酸盐浓度、二价铜离子浓度、氨浓度。合适的浸金条件是: 固液比为1∶5, 浸取温度60 ℃, 反应时间2 h, 硫代硫酸盐浓度0.4 mol/L, 二价铜离子浓度0.04 mol/L, 氨浓度0.45 mol/L, pH=9.5, 添加0.2%的SO₃^2-, 空气进气速率1 L/min。研究表明, 硫代硫酸盐能够非常有效地从废弃印刷线路板中浸取金。     

我国废弃线路板的物理处理技术评述

废弃线路板具有数量大、潜在价值高和环境危害大等特点,使得废弃线路板的资源化具有重要的经济回收价值和环境保护意义。机械物理法处理废弃线路板具有投资小、运行成本低、二次污染少等特点,成为当前研究的重点。本文介绍了我国近几年发展起来的采用机械物理法处理废弃线路板的主要工艺,分析、比较了各种工艺的优缺点及其关键技术与设备,并提出按照回收物料综合效率和环境权重来评价回收效果的好坏。     

Liberation of valuable materials in waste printed circuit boards by high-voltage electrical pulses

Printed circuit boards (PCBs) are found in every electrical and electronic equipment. In this study, epoxy resin was employed as the model material to conduct high-voltage (HV) electrical pulse experiments. A complete liberation of PCBs was achieved using SELFRAG Lab, and the surface morphology and chemical composition of suspended particles were analyzed by SEM. The results show that the liberation and crushing mechanism of PCBs mainly include the formation and expansion of discharge channels, transformation of shock wave, reflection and refraction effects, and physical and chemical reactions under the high-pressure environment; among all of them, the physical and chemical reactions between metal and organics are specific phenomena, which only exist when using HV electrical pulses for the crushing process of waste PCBs. Furthermore, the results also show that HV electrical pulses can achieve a narrow-fraction metal concentration; this feature is conducive for the separation of metals from epoxy resin in the future. In particular, the crushing performance reaches its best level when the electrical pulse reaches 400, during which 97.92% copper was accumulated in −2 mm products.     

Distribution of heavy metals during pyrolysis of waste printed circuit boards

The volatilization behavior of Cu, Pb, Sn, Sb, Ni, Zn, Mn, Co, Cr, Cd during pyrolysis of waste printed circuit boards was investigated in a bench-scale fixed-bed pyrolysis system. It was found that volatility of heavy metals increases with operating temperature elevating, and bromine and vacuum have an obvious promoting effect on volatility of most of heavy metals. Over 99% weight of Cu and Ni are still remained in solid residue after pyrolysis, about 20% weight of Sb, Zn and Cd are transfered into liquid and gas during a pyrolysis process at 600 ℃, volatilization fractions of Pb, Sn, Mn, Co, Cr are less than 10% at the same conditions. The contents of heavy metals in liquid and gas products depend on not only volatility of metals, but also their initial contents in printed circuit boards, pyrolysis liquid and gas are primarily contaminated by Cu, Pb, Sn, Sb and Zn, their contents in liquid vary from 10^2 to 10^3 pg/mL, Mn, Co, Cr, Cd were detected only at very low level, less than 10 μg/mL.     

废旧印刷电路板火法冶金处理技术的研究进展

废旧印刷电路板既属于危险废弃物,又是重要的有色金属二次资源,寻求一种清洁高效的工业化回收处理方法,对保护生态环境、发展循环经济以及实现铜工业“双碳”目标都具有重要意义。本文系统梳理了焚烧法、热解法以及熔炼法等火法冶金处理技术的国内外最新研究成果,指出了影响其工业化应用的关键问题,并对未来的发展趋势进行了展望,旨在为废旧印刷电路板的大规模工业化回收处理提供参考。     

氨浸工艺从废弃线路板中回收铜的试验研究

电子废弃物中含有多种重金属及有毒有害物质,也含有一定量的铜、金、银、锌等有价金属,大量电子废弃物的肆意堆存不仅占用了大量土地,也造成了严重的环境污染,导致了资源的严重浪费。从电子废弃物中回收有价金属元素具有重要经济和社会意义。本试验以废弃电脑主板为原料,采用氨水-氯化铵为浸出剂进行湿法浸铜工艺研究。研究表明:最较浸出工艺条件为粉碎时间为30 s、氨水浓度为3 mol/L、氯化铵浓度为2 mol/L、浸出温度为45℃、搅拌速度为450 rpm、浸出时间为2 h。在较佳工艺条件下进行废弃线路板氨浸试验,铜浸出率大于88%,铁不浸出,实现了铜的高效选择性浸出。     

废电路板中金属富集体及铜的浮选回收

基于响应面曲线法对-0.45mm废电路板物料中金属与非金属浮选分离条件进行优化,结果表明,-0.45mm物料最佳浮选条件为：浓度为100g/L、转速为2100rpm、充气量为100L/h、入料粒度0.3mm～0.15mm,该条件下回收沉物中金属质量分数为89.7%,金属回收率达90.28%。在该优化条件下,对-0.074mm金属富集体中铜进行浮选研究,确定最佳药剂用量为:活化剂(Na2S)150g/t、起泡剂(C8H18O)200g/t、捕收剂(C4H9OCS2Na)200g/t,浮选得到铜精矿中铜的回收率为95.99%。金属混合物以及金属混合物中铜的回收率均在90%以上,实现了废电路板中金属混合物及铜的高效浮选回收。     

The effect of flotation and parameters for bioleaching of printed circuit boards

Waste electrical and electronic equipment (WEEE) is currently one of the fastest growing waste streams in the world. Typical for WEEE is the high content of valuable and precious metals, as well as harmful contaminants like halogens, flame retardant chemicals and plastics. Currently, WEEE treatment and metal recovery methods are imperfect, polluting and energy intensive. In this paper, novel treatment possibilities are outlined for printed circuit boards (PCB) utilizing both the flotation separation technique and acid bioleaching. Flotation, conducted after crushing and sieving of PCB, produced two fractions: metal-rich concentrate, which is more suitable for pyrometallurgical treatment than untreated PCB, and metal-poor froth suitable for acid bioleaching. It was seen that especially low pH (1.6), high initial Fe²⁺ concentration (7.8 g/l) and low PCB froth concentration in the bioleaching solution (50 g/l) were beneficial for the rapid and selective dissolution of copper. With these parameters, 99% of copper was solubilized from PCB froth in bioreactor treatment, with Cu (6.8 g/l) and Fe (7.0 g/l) being the only major metallic elements in bioleaching solution.     

废弃线路板尾渣选冶联合提纯新工艺

采用“粉碎-重力分选-生物浸出”工艺对一种铜含量为0.93％的废弃线路板尾渣进行处理.结果表明,将废弃线路板尾渣深度粉碎到粒径小于0.1 mm,经细粒摇床重选后,金属粉末中铜含量为60.21％,非金属粉末中铜含量为0.23％;采用T.f菌在25～35℃,浸出液pH=2的条件下,对非金属粉末浸出48 h,浸出渣中铜含量降...     

废弃线路板中金属资源的物理回收

电路板或线路板作为电子电气设备的核心组成部分,是电子工业的基础。废弃线路板因具有资源性和危害性,近年来备受关注:无论是在发达还是发展中国家,从废弃线路板中回收金属的做法已盛行,然而废弃线路板中有毒有害组分对环境的污染不容忽视。因此,经济高效地回收WPCBs中的有用部分,尤其是贵重金属,并安全妥善地处置有害部分具有重要的现实意义。采用如破碎、筛分、重力分选、磁力分选或静电分选等物理方法,对废弃线路板进行破碎解离及金属富集是所有回收工艺中必要的前提步骤,相比其他方法也更为灵活有效。