6 - Experimental Study of Phase Equilibria in the...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Experimental Study of Phase Equilibria in the “FeO”-ZnO- (CaO 1 SiO 2 ) System with CaO/SiO 2 Weight Ratios of 0.33, 0.93, and 1.2 in Equilibrium with Metallic Iron EVGUENI JAK, BAOJUN ZHAO, and PETER C. HAYES The pseudoternary sections “FeO”-ZnO-(CaO 1 SiO 2 ) with CaO/SiO 2 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 8 C to 1300 8 C (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 1 SiO 2 ). The sections contain primary-phase fields of wustite (Fe x Zn 1 2 x O 1+ y ), zincite (Zn z Fe 1 2 z O), fayalite (Fe w Zn 2 2 w SiO 4 ), melilite (Ca 2 Zn u Fe 1 2 u Si 2 O 7 ), willemite (Zn v Fe 2 2 v SiO 4 ), dicalcium silicate (Ca 2 SiO 4 ), pseudowollastonite and wollastonite (CaSiO 3 ), and tridymite (SiO 2 ). The phase equilibria involving the liquid phase and the solid solutions have also been measured. I. INTRODUCTION computer package F*A*C*T [3] to characterize phase rela- tions and thermodynamic properties in the six-component T HE system Ca-Fe-Si-O-Zn forms the basis for the system PbO-ZnO-SiO 2 -CaO-FeO-Fe 2 O 3 over a wide range chemical description of a range of lead and zinc smelting of compositions important to zinc/lead industrial smelting slags. Lead oxide is reduced from slag to the lead metal, processes. Studies of a number of subsystems within this so that the PbO content in the final slag is low. Previous overall research program have already been described in experimental data on the phase equilibria and thermodynam- previous publications by the present authors. [1,2,4–20] ics of this important pyrometallurgical system have been reviewed by the present authors. [1] The lack of systematic II. EXPERIMENTAL RESULTS phase-equilibrium data was attributed to the experimental difficulties associated with high vaporization rates of zinc The experimental techniques used in the present investiga- in reducing conditions at high temperatures. [1,2] Novel exper- tion, which involve high-temperature equilibration of metal imental techniques enabling the liquidus and phase equilibria and oxide powders, quenching, and electron probe X-ray at high zinc concentrations in equilibrium with metallic iron microanalysis (EPMA), have been described in detail in to be determined were described in previous publications of previous publications. [1,2] The overall accuracy of the tem- the present authors. [1,2] Using this approach, a new experi- perature control during experiments is within 6 5 K, and the mental study of the phase equilibria of the “FeO”-ZnO-SiO 2 compositions were measured with an accuracy within 6 1 system in equilibrium with metallic iron has recently been wt pct. [1,2] carried out. [2] New experimental data have also been reported by the present authors for the “FeO”-ZnO-(CaO 1 SiO 2 ) A. Phases Present system with a CaO/SiO 2 weight ratio of 0.71 in equilibrium with metallic iron. [1] Microstructural examination of samples in the Ca-Fe-O-
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/13/2011 for the course METALLURGY 1107 taught by Professor Hegurange during the Three '10 term at Murdoch.

Page1 / 14

6 - Experimental Study of Phase Equilibria in the...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online