Effect of Gas Atmosphere on the Phase Chemistry in the CaO-FeO-Fe_2O_3-SiO_2 System Related to Iron Ore Sinter-making

摘要

Experimental phase equilibria studies have been carried out to investigate the phase chemistry in the CaO-"Fe_2O_3"-SiO_2 system related to the iron ore sinter making in 1 atm CO_2 at 1 200-1 230°C. The measurements have been performed using a modified experimental technique involving high temperature equilibration and rapid quenching followed by electron probe X-ray microanalysis (EPMA). In contrast to the equilibria in air, the experimental results show that no silico-ferrite of calcium (SFC solid solution) is formed in 1 atm CO_2 within the temperature range investigated; that is, the SFC phase is not stable at liquidus temperatures. The liquidus for the iron-rich corner of the CaO-"Fe_2O_3"-SiO_2 system in CO_2 atmosphere for the spinel (magnetite Fe_3O_4> and dicalcium silicate (C_2S = Ca_2SiO_4) primary phase fields has been proposed.