Solvent extraction equilibria of nickel from ammonium nitrate solution with LIX84I

The equilibrium distribution ratios of nickel(11) ion between LIX84I (active component 2-hydroxy-5-nonylacetophenone oxime (HNAPO)), dissolved in a non-polar diluent and 3 kmol m(-3) ammonium nitrate solution are measured in the pH range 2-10 at 298 K. The effect of pH on the distribution ratio of nickel is analyzed based on the extraction equilibrium model assuming that the extracted complex has the stoichiometry of 1:2 (Ni:HNAPO). The successive aggregation of HNAPO in the organic phase and the nickel-ammine complex formation in the aqueous phase are considered, where the acid dissociation constant of ammonium ion, measured by the half-neutralization method, is used. The equilibrium constants for the extraction, successive aggregation, and distribution of the nickel extractant complex between the aqueous and organic phases are determined to be 4.90 x 10(-5), 9.9 (kmol m(-3))(-1) and 1 x 10(-4), respectively. These constants reproduce the experimental distribution data with good accuracy. (C) 2010 Elsevier B.V. All rights reserved.

在298 K下，在pH值为2 - 10的范围内，测量了溶解在非极性稀释剂中的LIX84I（活性成分2 - 羟基 - 5 - 壬基苯乙酮肟（HNAPO））与3 kmol/m³硝酸铵溶液之间镍（II）离子的平衡分配比。基于萃取平衡模型分析了pH值对镍分配比的影响，假设萃取配合物的化学计量比为1:2（镍:HNAPO）。考虑了HNAPO在有机相中的连续聚集以及水相中镍 - 氨配合物的形成，其中使用了通过半中和法测量的铵离子的酸解离常数。水相和有机相之间镍萃取剂配合物的萃取、连续聚集和分配的平衡常数分别确定为4.90×10⁻⁵、9.9（kmol/m³）⁻¹和1×10⁻⁴。这些常数能很好地重现实验分配数据。© 2010 Elsevier B.V.保留所有权利。