Abstract
Organophosphorus reagents are well known in solvent extraction. Commercial operations for the separation of cobalt from nickel have been successfully carried out using organophosphoric, -phosphonic, and -phosphinic acid extractants. Two new reagents in this class are the mono and dithio analogs of the commercial dialkylphosphinic acid, Cyanex 272. The replacement of oxygen by sulfur in these reagents enables extraction to be carried out at much lower pH. Characterization of Cyanex 272, Cyanex 302 (bis-(2,4,4-trimethylpentyl)-thiophosphinic acid), and Cyanex 301 (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid) has been undertaken. A comparison of the solvent extraction behavior of metallurgically important first-row transition metal ions from acidic sulfate solution by these reagents is reported. Distribution coefficients shift to lower pH with increasing sulfur substitution and decreasing pKa of the extractant, the greatest effect being observed for nickel. Stoichiometry of the extraction reactions, and the nature of the metal complexes formed have been determined using slope analysis techniques and spectroscopic measurements.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 345-365 |
| Number of pages | 21 |
| Journal | Hydrometallurgy |
| Volume | 30 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - Jun 1992 |
ASJC Scopus subject areas
- Metals and Alloys
- Industrial and Manufacturing Engineering
- Materials Chemistry