Marian Kucharski

A Study on the Copper Recovery from the Slag of the Outokumpu Direct-to-Copper Process

The work was aimed at the investigation of the influence of the carbon reducer’s surface on the rate of copper removal from the slag obtained from the flash direct-to-blister process at the Głogów smelter in Poland. It was found that, under our experimental conditions, the copper recovery from the slag slightly increases as the slag/carbon interface increases. It is very likely that the results depend on the geometry of the investigated system as well as the slag foaming phenomenon. The increase of the slag/carbon interface does not noticeably change the final copper content in the slag. The obtained results do not follow any of the reaction rate equations. Therefore, it can be suggested that the slag foaming plays the key role in the experiments by increasing the reduction surface. In addition, the investigated slag has a high viscosity, which hampers the mass transfer in this slag. This hypothesis is supported by the fact that the slag layer situated below the graphite penetrator was found to be of a different color than the slag in the vicinity of that penetrator, where it was agitated by the CO and CO2 gases generated by the reactions of the slag reduction. Also, the slag in the layer under the penetrator contained more copper than the slag above this layer.

SnZn system. Correlation between thermodynamic properties, physical properties, structure and phase diagram

Abstract There is a good deal of ambiguity in the thermodynamic data for SnZn alloys reported by various authors. Thermodynamic studies for this system have shown that ΔH > 0, and also a negative deviation of ΔCp from the Neumann-Kopp rule. These facts indicate a transitional character of the SnZn alloys between systems with a miscibility gap and those with a compound-forming tendency. However, the calculated structural parameters of Bhatia-Thornton, Scc(0) and S(0)thermodynamic, do not exhibit any extrema. The isothermal relations of the viscosity and of the surface tension are similar, and decrease for Zn-rich alloys. The surface ‘phase’ is characterized by a pronounced tin enrichment by comparison with the bulk phase. In addition, the thermodynamic properties of the surface ‘phase’ indicate a negative deviation from ideality, while the bulk phase exhibits a positive deviation.

The surface tension and density of Ag–Bi–Sn alloys

Abstract The sessile drop method has been used to measure the density and surface tension of liquid Ag–Bi–Sn mixtures. The density of these alloys shows linear dependence on temperature for all the compositions investigated. However, the surface tension shows curvilinear dependence on temperature for all of the compositions, except for those of a low silver content. The experimental values of the surface tension of Ag–Bi–Sn alloys are compared with those computed from the model, and relatively good agreement is observed.