(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 針對(duì)現(xiàn)有廢舊線路板元器件分離及錫回收工藝所存在環(huán)境污染嚴(yán)重、效率低、難以大規(guī)模推廣應(yīng)用等問(wèn)題，采用超聲輔助下SnCl4-HCl體系退除元器件管腳處焊錫，達(dá)到廢線路板元器件分離的目的；同時(shí)，采用隔膜電積技術(shù)回收退錫液中的錫并再生出SnCl4-HCl退錫劑。結(jié)果表明：在反應(yīng)溫度50 ℃、Sn4+濃度30 g/L、鹽酸濃度4.0 mol/L、超聲頻率40 kHz、超聲功率100 W的條件下，反應(yīng)20 min后廢線路板元器件管腳及過(guò)孔處的焊錫全被退除。以退錫后的液體為電解液，采用隔膜電積技術(shù)回收退錫液中的錫；在溫度35 ℃、電流密度200 A/m2、異極距5 cm、石墨板為陽(yáng)極、不銹鋼板為陰極的條件下進(jìn)行隔膜電積8 h，陰極得到了平整致密的電積錫，陰極電流效率97.3%，電錫純度99.9%，陽(yáng)極電流效率為88.8%，陽(yáng)極液再生出SnCl4-HCl溶液，可作為退錫液返回用于超聲退錫。
關(guān)鍵字: 廢線路板；元器件分離；錫；再生；隔膜電積技術(shù)
（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
