Mansur Marcelo Borges, Rocha Sônia Denise Ferreira, Magalhães Fernando Silva, Benedetto Jeaneth dos Santos
Department Engenharia Metalúrgica e de Materiais, Universidade Federal de Minas Gerais, Rua Espírito Santo, 35, # 2 andar, Centro, 30130-090 Belo Horizonte, MG, Brazil.
J Hazard Mater. 2008 Feb 11;150(3):669-78. doi: 10.1016/j.jhazmat.2007.05.019. Epub 2007 May 13.
The selective removal of zinc(II) over iron(II) by liquid-liquid extraction from spent hydrochloric acid pickling effluents produced by the zinc hot-dip galvanizing industry was studied at room temperature. Two distinct effluents were investigated: effluent 1 containing 70.2g/L of Zn, 92.2g/L of Fe and pH 0.6, and effluent 2 containing 33.9 g/L of Zn, 203.9g/L of Fe and 2M HCl. The following extractants were compared: TBP (tri-n-butyl phosphate), Cyanex 272 [bis(2,4,4-trimethylpentyl)phosphinic acid], Cyanex 301 [bis(2,4,4-trimethylpentyl) dithiophosphinic acid] and Cyanex 302 [bis(2,4,4-trimethylpentyl) monothiophosphinic acid]. The best separation results were obtained for extractants TBP and Cyanex 301. Around 92.5% of zinc and 11.2% of iron were extracted from effluent 1 in one single contact using 100% (v/v) of TBP. With Cyanex 301, around 80-95% of zinc and less than 10% of iron were extracted from effluent 2 at pH 0.3-1.0. For Cyanex 272, the highest extraction yield for zinc (70% of zinc with 20% of iron extraction) was found at pH 2.4. Cyanex 302 presented low metal extraction levels (below 10%) and slow phase disengagement characteristics. Reactions for the extraction of zinc with TBP and Cyanex 301 from hydrochloric acid solution were proposed.
在室温下，研究了通过液液萃取从锌热浸镀锌行业产生的废盐酸酸洗废水中选择性去除锌（II）而非铁（II）的方法。研究了两种不同的废水：废水1含有70.2g/L的锌、92.2g/L的铁，pH值为0.6；废水2含有33.9g/L的锌、203.9g/L的铁和2M盐酸。比较了以下萃取剂：磷酸三丁酯（TBP）、Cyanex 272 [双（2,4,4-三甲基戊基）次膦酸]、Cyanex 301 [双（2,4,4-三甲基戊基）二硫代次膦酸]和Cyanex 302 [双（2,4,4-三甲基戊基）单硫代次膦酸]。萃取剂TBP和Cyanex 301获得了最佳分离效果。使用100%（v/v）的TBP，通过一次接触从废水1中萃取了约92.5%的锌和11.2%的铁。使用Cyanex 301时，在pH值为0.3 - 1.0的条件下，从废水2中萃取了约80 - 95%的锌和不到10%的铁。对于Cyanex 272，在pH值为2.4时发现锌的最高萃取率（70%的锌，20%的铁被萃取）。Cyanex 302的金属萃取水平较低（低于10%），且相分离缓慢。提出了用TBP和Cyanex 301从盐酸溶液中萃取锌的反应。
