盐酸体系N503萃取分离铟铁行为研究

Behaviors of solvent extraction of indium and iron indium from hydrochloric acidwith N,N′- di(1-methyl-heptyl) acetamide (N503)

摘要:

研究了酰胺类萃取剂N503(N,N′?二(1?甲基庚基)乙酰胺)从盐酸溶液中萃取铟和铁的行为，考察了盐酸浓度、萃取剂浓度和氯离子浓度对铟、铁萃取率的影响。结果表明：盐酸浓度、萃取剂浓度对In(III)和Fe(III)的萃取率影响较显著，在研究的盐酸浓度范围内，溶液中铟、铁的萃取顺序为Fe(III)>In(III)>Fe(II)。当盐酸浓度为3 mol?L-1，N503浓度为20 %时，Fe(III)的萃取率接近100 %，In(III)的萃取率约为70 %，Fe(II)的萃取率小于1 %。因此Fe(III)与In(III)难以选择性萃取分离，Fe(II)与In(III)可以实现选择性萃取分离。且Fe(III)、In(III)萃合物反萃性能接近，均能被稀盐酸反萃，难以实现选择性反萃分离。因而，获得从盐酸溶液中萃取分离铟铁的工艺为：先采用铁粉将Fe(III)还原为Fe(II)，再采用N503选择性萃取，0.1 mol?L-1盐酸溶液反萃In(III)，铟铁的分离系数可以达到1400，为铟、铁的分离提供数据基础和理论指导。

Abstract:

The extraction behaviors of indium and iron by amide extractant named as N,N′- di(1-methyl-heptyl)acetamide (N503), from hydrochloric acid solution were studied. The effects of hydrochloric acid concentration, extractant concentration and chloride ions of aqueous phase on the indium and iron extraction were examined. The results show that hydrochloric acid concentration and extractant concentration are more significant to the extraction. In the range of hydrochloric acid investigated, the sequence of extracted ions in the solutionis Fe(III)>In(III)>Fe(II). The efficiency of Fe(III) and In(III) is almost 100 % and 70 %, however, Fe(II) is almost not be extracted, when the chloride acid concentration is 3 mg?L-1 and the extractant concentration is 20 %. So it is difficult to separate Fe(III) and In(III) by extraction, but Fe(II) and In(III) can be achieved by this process. Beside, due to the similar character of Fe(III) and In(III)-containing complex (easy stripping), separation of Fe(III) and In(III) cannot be achieved by stripping. Hence, the craft of separation of indium and iron from hydrochloric acid solution contains reducing Fe(III) to Fe(II) with iron powder, extracting with N503 and stripping by 0.1 mol?L-1HCl. The separation factor is 1400, which provides a basic data and theory instruction for the separation of indium and iron.