Experimental Study of Ferrous Calcium Silicate Slags: Phase Equilibria at $$ {\text{P}}_{{{\text{O}}_{2} }} $$ Between 10−5 atm and 10−7 atm

Abstract

Ferrous calcium silicate slags, whose principal components are ''FeO x ''-CaO-SiO 2 , are widely used in copper smelting and converting operations. In the current study, high-temperature equilibration and rapid quenching techniques were used to study the phase equilibria of the ferrous calcium silicate slags. The compositions of phases in the slags were measured accurately using electron probe X-ray microanalysis (EPMA). The phase equilibria of the system have been characterized at oxygen partial pressures between 10 À5 atm and 10 À7 atm at selected temperatures between 1473 K and 1623 K (1200°C and 1350°C). The effects of oxygen partial pressure and temperature on the compositions of phases in the slags are presented.

Phase Equilibrium Study of ZnO-“FeO”-SiO2 System at Fixed Po2 10−8 atm

“…The present results in the system "FeO"-SiO 2 at Po 2 10 -8 atm are compared with previous studies 10,11) and FactSage 12) calculations as shown in Figure 1. It can be seen from Figure 1 that the present data are in good agreement with the previous data.…”

“…It can be seen from Figure 1 that the present data are in good agreement with the previous data. 10,11) Experimentally determined liquidus temperatures in the present and previous studies are higher than those predicted by FactSage 6.2 12) in wustite and spinel primary phase field. 10,11) and FactSage 6.2 12) predictions on "FeO"-SiO 2 system at Po 2 10 -8 atm…”

High-temperature experimental and thermodynamic modelling research on the pyrometallurgical processing of copper

“…The experimental technique and equipment have been used to accurately characterize high-temperature phase equilibria in various slag systems including CaO-"FeO"-SiO2 system [8][9][10] , CaO-"FeO"-SiO2-S system 11 , CaO-"FeO"-SiO2-MeOx (Me=Al, Mg) systems 12 , "Cu2O"-SiO2-MeOx (Me=Al, Ca, Mg, Fe) systems 13,14 , "Cu2O"-CaO-"Fe2O3" system 15 , "Cu2O"-CaO-"FeO"-SiO2 system 16,17 , and more.…”

Experimental Study of Ferrous Calcium Silicate Slags: Phase Equilibria at $$ {\text{P}}_{{{\text{O}}_{2} }} $$ Between 10–8 atm and 10–9 atm

“…[4] Initial mixtures were prepared by mixing high-purity powders of CaO (calcined at 1173 K (900°C) from 99.0 wt pct pure CaCO 3 powder), SiO 2 (99.99 wt pct pure 1-to 3-mm fused lump that had been ground with an agate mortar and pestle), Fe 2 O 3 (99.99 wt pct pure), and Fe (99.9 wt pct pure). The initial compositions of the samples were selected such that at equilibrium the liquid phase would be present together with one or more solid phases.…”

“…They demonstrated that accurate measurement of phase equilibria of these slag systems can be achieved by a careful attention to factors such as: oxygen partial pressure and temperature, sample preparation, sample quenching method, technique for measuring the compositions of phases, [3] and importantly, confirmation of achievement of equilibrium. [4] This approach has been used successfully in the investigation of various complex ferrous calcium silicate slags, for example: ''FeO''-CaO-SiO 2 -''Cu 2 O'', [5] ''FeO''-CaO-SiO 2 -Al 2 O 3 -MgO, [6] and ''FeO''-CaO- [7] In the current study, the phase equilibria in the ferrous calcium silicate slag (''FeO''-CaO-SiO 2 ) system are determined at an oxygen partial pressure of 10 -8 atm at temperatures between 1423 K and 1623 K (1150°C and 1350°C), and at an oxygen partial pressure of 10 -9 atm at temperatures of 1473 K and 1573 K (1200°C and 1300°C).…”