Determination of the Carbon-Saturated SiO2-CaO-TiOx Phase Diagram at 1773 K

Takashi Murata*, Katsunori Yamaguchi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In the present work, a pyrometallurgical process is considered, in which platinum group metals (PGMs) from the hydrometallurgical residue containing mainly TiO2 are concentrated in a metal phase with Cu as a collector, and TiO2 is separated into the slag phase, with SiO2 and CaO as fluxing agents. Efficient separation is thought to be possible only if the slag remains a homogenous liquid, with no solid phases present. In this study, the phase diagram of the SiO2-CaO-TiOx system equilibrated with graphite and CO gas at 1773 K was experimentally determined to find the liquid slag composition region with a large solubility of TiOx. The results showed that at high TiOx slag concentrations, a reaction occurred with the graphite crucible to form solid TiC. Additionally, the solubility of TiOx in the slag increased as the ratio of mass%CaO/mass%SiO2 decreased.

Original languageEnglish
Pages (from-to)547-553
Number of pages7
JournalJournal of Phase Equilibria and Diffusion
Issue number5
Publication statusPublished - 2022 Oct


  • phase equilibria
  • precious metal smelting
  • pyrometallurgy
  • slag
  • titanium oxide

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Metals and Alloys
  • Materials Chemistry


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