Article ID Journal Published Year Pages File Type
1482263 Journal of Non-Crystalline Solids 2011 12 Pages PDF
Abstract

Factors controlling the rate at which chromium oxide reaches saturation in Na2O–xSiO2 liquids have been studied as a function of melt composition and oxygen fugacity. Under an oxidizing atmosphere, liquid Na2CrO4 or Cr2O3 crystals can be in equilibrium with soda-silicate melts, depending on the concentration of sodium in the studied system. Under reducing conditions, NaCrSi2O6 is stabilized in silica-rich melts when T is lower than 1160 °C, while Cr2O3 is in equilibrium with the sodium-rich melts when T is above 1160 °C. The chromium oxide (Cr2O3) to pyroxene (NaCrSi2O6) transformation is described in terms of the time required to reach chemical and textural equilibrium. Na2CrO4, NaCrSi2O6, and Cr2O3 phase stability domains are reported as well as the Na2O–SiO2–Cr2O3 phase diagram in the studied temperature and fO2 range.

Research Highlights►Development of a reactor in order to control physico-chemical parameters, ►optimization of the conditions of analysis by EPMA, ►description of the complex mechanism of chromia dissolution in silicate melts, ►determination of the domain of existence of a pyroxene phase.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
Authors
, , , , , , , ,