As part of a fundamental study of copper smelting processes using oxygen or oxygen-enriched air as a blowing gas, phase equilibrium and distribution of minor elements between copper matte and SiO 2 -saturated FeO X -SiO 2 -MgO-based slag containing 5 to 10 wt pct MgO have been investigated at 1573 K under the SO 2 partial pressures of 10.1, 50.7, and 101.3 kPa. The copper and sulfur solubilities in the slag were found to be independent of p SO 2 when the matte grade was specified, and this behavior was ascribed to the constancy of ( p O 2 /p S 2 ) against p SO 2 at a given matte grade. When the distribution ratio of a minor element (X) between the slag and matte phases was defined as L s/m x ϭ (wt pct X in slag)/{wt pct X in matter}, L s/m x for arsenic, antimony, and bismuth at a given matte grade increased with increasing p SO 2 . On the other hand, the distribution ratio of silver at a given matte grade was almost constant against p SO 2 .

No abstract

Phase relations and the liquidus surface in the system "MnO"-Al 2 O 3 -SiO 2 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 (SiO 2 ); mullite (3Al 2 O 3 и2SiO 2 ); corundum (Al 2 O 3 ); galaxite (MnOиAl 2 O 3 ); manganosite (MnO); tephroite (2MnOиSiO 2 ); rhodonite (MnOиSiO 2 ); spessartine (3MnOиAl 2 O 3 иSiO 2 ); and the compound MnOиAl 2 O 3 и2SiO 2 .

Phase-equilibrium data and liquidus isotherms for the system "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) at silicomanganese alloy saturation have been determined in the temperature range of 1373 to 1723 K. The results are presented in the form of the pseudoternary sections "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) with Al 2 O 3 /SiO 2 weight ratios of 0.55 and 0.65. The primary-phase fields have been identified in this range of conditions. and, subsequently, mounted and polished for further examination. On quenching, the liquid phase is retained as a glass. The microstructures and phases present in quenched slag samples were first examined using the optical microscope. The phases present were then identified by electron probe X-ray microanalysis (EPMA) using a JEOL* 8800L instru-*JEOL is a trademark of Japan Electron Optics Ltd., Tokyo. ment with wavelength-dispersive spectrometers. A rhodonite (MnSiO 3 ) standard was used for manganese, a spessartine (3MnOиAl 2 O 3и 3SiO 2) standard was used for aluminium, and a wollastonite (CaSiO 3 ) standard was used for silicon and calcium calibration. These standards were obtained from the Charles M. Taylor Company. The Duncumb-Philibert ZAF correction procedure supplied with the JEOL 8800L was applied. The average accuracy of the EPMA measurements was within Ϯ1 wt pct. III. RESULTS A. Pseudoternary Section "MnO"-CaO-(AlThe experimentally determined liquidus surface for the pseudoternary section of "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) with an Al 2 O 3 /SiO 2 weight ratio of 0.55 is presented in Figures 1 through 3. Figure 1 shows the data points obtained in the present investigation. Figures 2 and 3 provide more detailed views of the section in the high-SiO 2 , and low-CaO regions of the system, respectively. The chemical compositions of the liquid and solid phases determined in this study are given in Table I. The liquidus for the CaO-Al 2 O 3 -SiO 2 and "MnO"-Al 2 O 3 -SiO 2 sections is taken from previous studies. [2,3] The pseudoternary system "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) with an Al 2 O 3 /SiO 2 weight ratio of 0.55 contains the primaryphase fields of mullite (3Al 2 O 3и 2SiO 2, or A 3 S 2 ), corundum (Al 2 O 3 , or A), spessartine (3MnOиAl 2 O 3 и3SiO 2 , or M 3 AS 3 ), galaxite (MnOиAl 2 O 3 , or MA), manganosite solid solution ((Mn,Ca)O), a-dicalcium silicate (2CaOиSiO 2 , or C 2 S), aЈdicalcium silicate (2CaOиSiO 2 , or C 2 S), gehlenite (2CaOи Al 2 O 3 иSiO 2 or C 2 AS), and anorthite (CaOи Al 2 O 3 и2SiO 2 , or CAS 2 ). B. Pseudoternary Section "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) at Al 2 O 3 /SiO 2 ϭ 0.65The experimentally determined liquidus surfaces and liquidus isotherms for the pseudoternary section of "MnO"-CaO-(Al 2 O 3 ϩ SiO 2 ) with an Al 2 O 3 /SiO 2 weight ratio of