PHASE EQUILIBRIA AND DISTRIBUTION OF MINOR ELEMENTS BETWEEN LIQUID CU-Zn-Fe(Iron-Saturation) ALLOY AND CaO-SiO_2-FeO_x SLAG

摘要

As a fundamental study of the new zinc smelting process using liquid copper as a smelting medium to recover zinc in a liquid Cu-Zn base alloy, distribution ratios of zinc, L_(zn)~(s/c) between liquid Cu-Zn-Fe (iron-saturation) alloys and CaO-SiO_2-FeO_x slags were determined at 1473 and 1523 K under varying Zinc content in the alloy from about 0.5 to 30 masspercent and varying basicity, Q, (Q = percent CaO/(percent CaO + percent SiO_2)) of the slag from 0 to 1.L_(zn)~(s/c) for the alloy with a low zinc content less than 1 mass percent is almost constant against percent FeO_x in the slag and decreases with increasing Q. The activity coefficient of ZnO in the slag, (#sigma#_(zno)), which was calculated from the measured oxygen potential and L_(zn)~(s/c) increases with increasing 0 and is about 3 at Q =0.42.L_(zn)~(s/c) for the alloy with a high zinc content more than 1percent increases monotonously with the zinc content. The calculated (#sigma#_(zno)) is almost constant. This suggests that ZnO in the CaO-SiO_2-FeO_x-ZnO slag approximately obeys a Henry's law up to the relatively high concentration of ZnO. (#sigma#_(zno)) increases with increasing Q and is about 5 at Q=1.Based on the obtained L_(zn)~(s/c) ,the fractional distribution of zinc between the alloy, 5Z~~g and gas phases was calculated for the newly proposed Process to recover zinc by means of the smelting medium of liquid copper.