| Description |
xii, 122 leaves : illustrations ; 29 cm |
| Summary |
"Slag-bullion equilibration tests were carried out to establish tie-lines between lead-rich and oxysulfate phases at several combinations of temperature and SO₂ partial pressure. The results obtained using sampling and quenching techniques were in good agreement and indicated the oxysulfate phase deviated very little from being a PbO-PbSO₄ melt. This deviation became more and more appreciable with increasing SO₂ pressure and/or temperature. However, it was less acute than previously determined. An analytical solution was performed to establish equilibrium tie-lines between Pb-S and PbO-PbSO₄ melts. The solution relied on subregular solution models by Eric and Timucin for the Pb-S melt, and by Jacob and Toguri for the PbO-PbSO₄ melt. The results were used to derive an equation for the standard free energy of formation of PbSO₄(ℓ) in the temperature range of 1200 to 1450 K. The UMR version of SOLGASMIX, STEPSOL, was used in conjunction with the above metal and slag activity models to establish the tie-lines and to extend the results to regions not tested experimentally. The results allowed consideration of possible direct smelting processes for clean lead concentrates, such as a typical Missouri concentrate. Excellent agreement between model predictions and analytical solution was obtained, suggesting confidence in the usefulness of the model. There is, however, a lack of agreement between the experimental data and the model predictions. The sources of this disappointing problem are not fully understood at this point"--Abstract, leaf ii. |
|
