Pyrometallurgy Innovation Centre (PYROSEARCH)

  • Experimental study of phase equilibria in the PbO-ZnO-"Fe2O3"-(CaO+SiO2) system in air for the lead and zinc blast furnace sinters (CaO/SiO2 weight ratio of 0.933 and PbO/(CaO+SiO2) ratios of 2.0 and 3.2)

    Jak, Evgueni; Zhao, Baojun; Hayes, Peter C.; Harvey, Ian (2007). Experimental studies on phase equilibria and liquidus in the multicomponent system PbO-ZnO-CaO-SiO2-FeO-Fe2O3 in air have been conducted over the temperature range between 1323 K (1050 degreesC) and 1623 K (1350 degreesC) to characterize the phase relations of the complex slag systems encountered in lead and zinc blast furnace sinters. The liquidus in two pseudoternary sections ZnO-Fe2O3-(PbO + CaO + SiO2) with the CaO/SiO2 weight ratio of 0.933 and PbO/(CaO + SiO2) weight ratios of 2.0 and 3.2 have been constructed.

  • Phase equilibrium data and liquidus for the system "MnO"-CaO-(Al2O3+SiO2) at Al2O3/SiO2 of 0.41

    Roghani, G.; Jak, E.; Hayes, P. C. (2007). Phase-equilibrium data and the liquidus for the system. "MnO"-CaO-(Al2O3-SiO2) at a manganese-rich alloy saturation have been determined in the temperature range from 1423 to 1723 K. The results are presented in the form of a pseudoternary section "MnO"-CaO-(Al2O3 + SiO2) with an Al2O3/SiO2 weight ratio of 0.41. The following primary phases are present in the range of conditions investigated:, 3Al(2)O(3).2SiO(2); SiO2; MnO.Al2O3-2SiO(2); (Mn,Ca)O.SiO2; 2(Mn,Ca)O.SiO2; MnO.Al2O3; (Mn,Ca)O; alpha-2CaO.SiO2; alpha'-2CaO.SiO2; 2CaO.Al2O3.SiO2; CaO.SiO2, and CaO.Al2O3.2SiO(2). The presence of alumina in this system is shown to have a significant effect on the liquidus compared to the system "MnO"-CaO-SiO2, leading to, the stabilization of the anorthite and gehlenite phases.

  • Phase equilibrium studies in the "MnO"-Al2O3-SiO2 system

    Roghani, G.; Jak, E.; Hayes, P. C. (2007). Phase relations and the liquidus surface in the system "MnO"-Al2O3-SiO2 at manganese-rich alloy saturation have been investigated in the temperature range from 1373 to 1773 K. This system contains the primary-phase fields of tridymite and cristobalite (SiO2); mullite (3Al(2)O(3).2SiO(2)); corundum (Al2O3); galaxite (MnO.Al2O3); manganosite (MnO); tephroite (2MnO.SiO2); rhodonite (MnO.SiO2); spessartine (3MnO.Al2O3.SiO2); and the compound MnO.Al2O3.2SiO(2).

  • Experimental study of phase equilibria in the "FeO"-ZNO-(CaO+SiO2) system with the CaO/SiO2 weight ratio of 0.71 at metallic iron saturation

    Jak, Evgueni; Zhao, Baojun; Hayes, Peter C. (2007). The pseudoternary section FeO-ZnO-(CaO + SiO2) with a CaO/SiO2 weight ratio of 0.71 in equilibrium with metallic iron has been experimentally investigated in the temperature range from 1000 degreesC to 1300 degreesC (1273 to 1573 K). The liquidus surface in this pseudoternary. section has been determined in the composition range of 0 to 33 wt pct ZnO and 30 to 70 wt pct (CaO + SiO2)The system contains primary-phase fields of wustite (FexZn1-xO1+y), zincite (ZnzFe1-zO), fayalite (FewZn2-wSiO4), melilite (Ca2ZnuFe1-uSi2O7), and pseudowollastonite (CaSiO3). The phase equilibria involving the liquid phase and the solid solutions have also been measured.

  • Phase equilibria and thermodynamics of zinc fuming slags

    Jak, E.; Hayes, P. (2007). A range of materials is treated in zinc fuming processes to recover metal values and produce benign slag waste products. The selection of the optimum process conditions in these various technologies can be greatly assisted by the use of a chemical thermodynamic model of the system. In this paper the effects of slag chemistry on the liquidus temperatures, subliquidus phase equilibria and thermodynamic properties are described by the F*A*C*T computer package with the new thermodynamic database of the ZnO-PbO-FeO-Fe2O3-CaO-SiO2 system. The implications of these findings for plant practice are discussed.

  • Coupled experimental and thermodynamic study of the Zn-Fe-Si-O system

    Jak, Evgueni; Hayes, Peter C.; Degterov, Sergei; Pelton, Arthuir D. (2007). Experimental and thermodynamic modeling studies have been carried out on the Zn-Fe-Si-O system. This research is part of a wider program to characterize zinc/lead industrial slags and sinters in the PbO-ZnO-SiO2-CaO-FeO-Fe2O3 system. Experimental investigations involve high-temperature equilibration and quenching techniques followed by electron probe X-ray microanalysis (EPMA). Liquidus temperatures and solid solubilities of the crystalline phases were measured in the temperature range from 1200 °C to 1450 °C (1473 to 1723 K) in the zinc ferrite, zincite, willemite, and tridymite primary-phase fields in the Zn-Fe-Si-O system in air. These equilibrium data for the Zn-Fe-Si-O system in air, combined with previously reported data for this system, were used to obtain an optimized self-consistent set of parameters of thermodynamic models for all phases.

  • Experimental study of phase equilibria in the "FeO"-ZnO-(CaO+SiO2) system with CaO/SiO2 weight ratios of 0.33, 0.93, and 1.2 in equilibrium with metallic iron

    Jak, Evgueni; Zhao, Baojun; Hayes, Peter C. (2007). The pseudoternary sections FeO-ZnO-(CaO + SiO2) with CaO/SiO2 weight ratios of 0.33, 0.93, and 1.2 in equilibrium with metallic iron have been experimentally investigated in the temperature range from 1000 degreesC to 1300 degreesC (1273 to 1573 K). The liquidus surfaces in these pseudoternary sections have been experimentally determined in the composition range from 0 to 33 wt pct ZnO and 30 to 70 wt pct (CaO + SiO2). The sections contain primary-phase fields of wustite (FexZn1-xO1+y), zincite (ZnzFe1-zO), fayalite (Fu(w)Zn(2-w)SiO(4)), melilite (Ca2ZnuFe1-uSi2O7), willemite (ZnvFe2-vSiO4), dicalcium silicate (Ca2SiO4), pseudowollastonite and wollastonite (CaSiO3), and tridymite (SiO2). The phase equilibria involving the liquid phase and the solid solutions-have also been measured.

  • Experimental study of phase equilibria in the PbO-Al2O3-SiO2 system

    Chen, S.; Zhao, B.; Hayes, P. C.; Jak, E. (2007).

  • Experimental study of phase equilibria in the PbO-MgO-SiO2 system

    Chen, S.; Zhao, B.; Jak, E.; Hayes, P. C. (2007). Equilibrium phase relations in the PbO-Al2O3-SiO2 system have been investigated experimentally by means of high-temperature equilibration, quenching, and electron probe X-ray microanalysis (EPMA). The system has 21 primary phase fields including three monoxides (PbO, Al2O3, and SiO2), seven binary compounds (Al6Si2O13, PbAl2O4, PbAl12O19, Pb2Al2O5, PbSiO3, Pb2SiO4, and Pb4SiO6), and eleven ternary compounds (PbAl2Si2O8, Pb3Al10SiO20, Pb4Al2Si2O11, Pb4Al4SiO12, Pb4Al4Si3O16, Pb4Al4Si5O20, Pb5Al2Si10O28, Pb6Al2Si6O21, Pb8Al2Si4O19, Pb12Al2Si17O49, and Pb12Al2Si20O55). Three new ternary compounds, Pb4Al4SiO12, Pb4Al4Si5O20, and Pb12Al2Si17O49, were observed and characterized by EPMA. No extensive solid solution in any of the compounds was found in the present study. The liquidus isotherms were experimentally determined in most of the primary phase fields in the temperature range from 923 to 1873 K, and the ternary phase diagram of the PbO-Al2O3-SiO2 System has been constructed.

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