The formation of CaSO4 in the CaO-FeOx-Cu2O slags at 1250°C under high partial pressure of SO2

Katsunori Yamaguchi, Shigeru Ueda, Akira Yazawa

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Continuous converting of copper matte based on calcium ferrite slag of the CaO-FeOx-Cu2O system is an attractive technology for copper smelting. This slag containing approximately 20 mass% CaO can prevent the excess magnetite precipitation, but sometimes tends to separate CaSO4 under a high oxygen potential required to produce copper metal. To clarify the mechanism of gypsum formation, the precipitation of CaSO4 in the CaO-FeOx-Cu2O slag system equilibrating with blister copper has been determined at 1250°C under the SO2 partial pressures of 0.2, 0.6 and 1 atm. It was found that the formation of CaSO4 in the CaO-FeOx-Cu2O slags is enhanced with increasing SO2 partial pressure or CaO content and also increasing oxidation degree of the blister copper. The behavior of CaSO4 formation in the slag is also discussed thermodynamically based on the free energy calculations combining with the activity data derived from Takeda's data on the CaO-FeOx-Cu2O ferrite slag diagram. Both of experimental and thermodynamical results show good agreements in general.

Original languageEnglish
Title of host publicationProceedings - European Metallurgical Conference, EMC 2007
Pages227-237
Number of pages11
Publication statusPublished - 2007 Dec 1
Event4th European Metallurgical Conference, EMC 2007 - Dusseldorf, Germany
Duration: 2007 Jun 112007 Jun 14

Publication series

NameProceedings - European Metallurgical Conference, EMC 2007
Volume1

Conference

Conference4th European Metallurgical Conference, EMC 2007
CountryGermany
CityDusseldorf
Period07/6/1107/6/14

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Keywords

  • Blister copper
  • Calcium ferrite slag
  • Copper matte
  • Gypsum formation
  • Slag

ASJC Scopus subject areas

  • Metals and Alloys

Cite this

Yamaguchi, K., Ueda, S., & Yazawa, A. (2007). The formation of CaSO4 in the CaO-FeOx-Cu2O slags at 1250°C under high partial pressure of SO2. In Proceedings - European Metallurgical Conference, EMC 2007 (pp. 227-237). (Proceedings - European Metallurgical Conference, EMC 2007; Vol. 1).