Formation of CaSO 4 in the CaO-FeO x-Cu 2O slags

Sinichi Sato, Katsunori Yamaguchi

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Continuous converting of copper matte based on calcium ferrite slag of the CaO-FeO x-Cu 2O 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 CaSO 4 under a high oxygen potential required to produce copper metal. To clarify the mechanism of gypsum formation, the precipitation of CaSO 4 in the CaO-FeO x-Cu 2O slag system equilibrating with blister copper has been determined at 1473, 1523 and 1573 K under the SO 2 partial pressures of 0.2, 0.4, 0.6 and 1 atm. It was found that the formation of CaSO 4 in the CaO-FeO x-Cu 2O slags is enhanced with decreasing temperature, increasing SO 2 partial pressure or CaO content and also increasing oxidation degree of the blister copper. The behavior of CaSO 4 formation in the slag is also discussed thermodynamically based on the free energy calculations combining with the activity data derived from Prof. Takeda's data on the CaO-FeO x-Cu 2O ferrite slag diagram. Both of experimental and thermodynamical results show good agreements in general. It is found that the decreasing temperature, increasing CaO content or SO 2 pressure, and extensive oxidation of the blister copper tend to separate CaSO 4.

Original languageEnglish
Pages (from-to)447-449
Number of pages3
JournalHigh Temperature Materials and Processes
Volume30
Issue number4
DOIs
Publication statusPublished - 2011 Aug
Externally publishedYes

Fingerprint

slags
Slags
Copper
blisters
copper
Partial pressure
partial pressure
Ferrite
ferrites
Copper smelting
Ferrosoferric Oxide
smelting
Calcium Sulfate
Oxidation
oxidation
gypsum
Gypsum
Magnetite
magnetite
Free energy

Keywords

  • Activity of lime
  • Calcium ferrite slag
  • Gypsum formation

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Mechanics of Materials

Cite this

Formation of CaSO 4 in the CaO-FeO x-Cu 2O slags. / Sato, Sinichi; Yamaguchi, Katsunori.

In: High Temperature Materials and Processes, Vol. 30, No. 4, 08.2011, p. 447-449.

Research output: Contribution to journalArticle

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