Simultaneous Partition Experiment of Divalent Metal Ions between Sphalerite and 1 mol/L (Ni, Mg, Co, Fe, Mn)Cl2 Aqueous Solution under Supercritical Conditions

Etsuo Uchida, Keiko Wakamatsu, Naoki Takamatsu
2021 Minerals  
A simultaneous partition experiment of divalent metal ions was performed between sphalerite and 1 mol/L (Ni, Mg, Co, Fe, Mn)Cl2 aqueous solution under supercritical hydrothermal conditions of 500–800 °C and 100 MPa. The bulk partition coefficient that was defined by KPB(ZnS) = (xMeS/xZnS)/(mMeaq/mZnaq) followed the order of Zn ≑ Co ≑ Ni > Fe > Mn > Mg at all temperatures. In the partition coefficient versus ionic radius (PC–IR) diagrams with the logarithmic value of the bulk partition
more » ... t (log KPB(ZnS)) on the vertical axis, and the ionic radius of the six-fold coordinated site on the horizontal axis, Ni shows a positive partition anomaly, and the other elements were almost on the PC–IR curve. Based on the PC–IR curve, the optimum ionic radius for sphalerite existed where the ionic radius was slightly larger than Zn (~0.76 Å). A Ni positive partition anomaly may result from its large electronegativity.
doi:10.3390/min11040435 fatcat:j6i62pgj2zet3e3iu3s3l6gxmu