Removal of Tin and Copper from Liquid Iron by Al2O3-Saturated Ca-CaCl2 Slags at 1448 to 1648 K

Abstract

The removal of tin and copper from liquid iron by Al 2 O 3 -saturated Ca-CaCl 2 slags was carried out in separate alumina crucibles at 1448 to 1648 K that showed small partition ratios of less than 1. The tin content of the liquid iron typically decreased from its initial value of 50 to 40 wt pct and the (gross) copper content of the iron-copper mixture from 50 to 45 wt pct, at equilibrium. The small refining efficiencies (37 pct, maximum) of the slags, the initial composition of which were, in most cases, Ca-50 wt pct CaCl 2 , may be attributed to the significant dissolution in them of alumina, up to 42.0 wt pct (29.6 mol pct), in experiments with Sn, and up to 54.4 wt pct (38.6 mol pct), in experiments with Cu. Treating Ca as the solvent, a number of interaction coefficients such as e

A Derivation of a Quadratic Activity Coefficient vs Composition Relationship in a Quaternary System, A-B-C-D

“…; and e Sn CaCl 2 ) were determined simultaneously with the help of seven sets of results (and hence seven sets of equations). In a similar study of removing copper from liquid iron by Ca-CaCl 2 slags at 1448 K (1175°C), Ghosh [18] . The values of the interaction coefficients obtained from the two systems are listed in Table II.…”

“…[18] are all 1, and cannot be otherwise, it follows that the coefficients of dx A , dx B , dx C , and dx D in Eq. [19] and, hence in Eq.…”

“…In a study of removing tin from liquid iron by Ca-CaCl 2 slags in an alumina crucible at 1448 K (1175°C), Ghosh [18] studied the solubility of alumina in Ca-CaCl 2 slags. From the measured solubility of alumina at different concentrations of the components in the quaternary system Ca-Al 2 O 3 (saturated)-CaCl 2 -Sn (representing A-B-C-D) at equilibrium at 1448 K (1175°C) and by using Eq.…”

“…The values of the interaction coefficients obtained from the two systems are listed in Table II. As explained by Ghosh, [18] the values with a question mark ('?') are doubtful results.…”

“…Evaluated Interaction Coefficients e in Ca-Base Quaternary Slags Ca-Al 2 O 3 (Saturated)-CaCl 2 -Sn and Ca-Base Ternary Slags Ca-Al 2 O 3 (Saturated)-CaCl 2at 1448 K (1175°C)[18] …”