(中南大学 冶金与环境学院，长沙 410083)
摘 要: 针对现有废旧线路板元器件分离及锡回收工艺所存在环境污染严重、效率低、难以大规模推广应用等问题，采用超声辅助下SnCl4-HCl体系退除元器件管脚处焊锡，达到废线路板元器件分离的目的；同时，采用隔膜电积技术回收退锡液中的锡并再生出SnCl4-HCl退锡剂。结果表明：在反应温度50 ℃、Sn4+浓度30 g/L、盐酸浓度4.0 mol/L、超声频率40 kHz、超声功率100 W的条件下，反应20 min后废线路板元器件管脚及过孔处的焊锡全被退除。以退锡后的液体为电解液，采用隔膜电积技术回收退锡液中的锡；在温度35 ℃、电流密度200 A/m2、异极距5 cm、石墨板为阳极、不锈钢板为阴极的条件下进行隔膜电积8 h，阴极得到了平整致密的电积锡，阴极电流效率97.3%，电锡纯度99.9%，阳极电流效率为88.8%，阳极液再生出SnCl4-HCl溶液，可作为退锡液返回用于超声退锡。
关键字: 废线路板；元器件分离；锡；再生；隔膜电积技术
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Addressing the problems of serious environmental pollution, low efficiency, difficult to large-scale application and other issues in the separation of waste circuit board components and tin recycling process, a novel technology using an ultrasonic assisted process based on the SnCl4-HCl system was proposed. The technology adoption diaphragm electrowinning method recovered the tin from the tin stripping solution and regenerated the SnCl4-HCl stripping agent. The results show that, after 20 min at the reaction temperature of 50 ℃, Sn4+ concentration of 30 g/L, hydrochloric acid concentration of 4.0 mol/L, ultrasonic frequency of 40 kHz and ultrasonic power of 100 W, the waste circuit board components are separated completely. Under the conditions of temperature of 35 ℃, current density of 200 A/m2, heteropolar distance of 5 cm, graphite as anode and stainless-steel as cathode, the diaphragm electrowinning was carried out for 8 h. The cathode obtained flat and compact tin with cathode current efficiency of 97.3% and tin purity of 99.9%. The SnCl4-HCl solution is regenerated from the anode liquid and the anode current efficiency is 88.8%, which can be used as the reaction liquid for ultrasonic stripping tin.
Key words: waste printed circuit board; components separation; tin; recovery; membrane electro-deposition
