Solubility of Palladium in Alumina-Iron Silicate Melts

Dissolution and solubility of palladium in iron silicate melts saturated with alumina-iron spinel at 1300 degrees C has been measured using an equilibration-drop quenching technique combined with electron probe microanalysis and laser ablation-inductive coupled plasma-mass spectrometry analysis from polished sections. Composition of the resulting Fe-Pd alloy allowed estimation of the activity of palladium at different oxygen partial pressures, and, thus, the solubilities of palladium in the studied slags in conditions typical of copper and nickel smelting as well as slag cleaning at p(O2)=10(-5) to 10(-10) atm. The mechanism of palladium dissolution in the studied iron silicate slags was oxidation by formation of the monovalent oxide species PdO0.5 over the entire oxygen activity range of this study. Testing the applicability of the various palladium isotopes for quantitative analyses of Pd in these types of matrices resulted in a good fit of measured concentrations of Pd-104 and Pd-105 with interference-corrected Pd-106 and Pd-108.

Automated summary

The dissolution and solubility of palladium in iron silicate melts saturated with alumina-iron spinel at 1300 degrees C were measured, with findings indicating a relationship between the oxidation and activity of palladium with oxygen partial pressures that are applicable to copper and nickel smelting conditions. The study also revealed the applicability of palladium isotopes for quantitative analyses in these types of matrices.