Metallurgical and Materials Transactions B

, Volume 41, Issue 1, pp 74–79 | Cite as

Development of an Inert Anode for Electrowinning in Calcium Chloride–Calcium Oxide Melts

Article
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Abstract

Studies were performed investigating the anodic testing of calcium ruthenate for electrowinning in calcium chloride–calcium oxide melts. The results showed that calcium ruthenate may be suitable as an inert anode in calcium chloride containing melts as it exhibited a low rate of corrosion in melts containing a small amount of calcium oxide, capable of producing oxygen on its surface, and did not contaminate the melt. To reduce the amount of ruthenium in the anode, solid solutions of calcium ruthenate in calcium titanate were investigated. At low concentrations, the solid solution is a semiconductor with a relatively low conductivity at room temperature, but at the temperature of operation, 1173 K, the material is an excellent electronic conductor. The other way of reducing the amount of ruthenium is to coat the solid solution onto a substrate. In this way, the substrate would give the mechanical strength while the coating would give the electrical conductivity and corrosion protection. Calcium ruthenate-based anodes can endure long-term use in the laboratory under an applied electrical field with oxygen being liberated on the anode indicating that these materials are candidates for the electrowining in calcium chloride–calcium oxide melts.

Keywords

Calcium Chloride RuO2 Calcium Oxide Inert Anode Standard Free Energy Change 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Notes

Acknowledgment

The authors are grateful to the EPSRC for financial support.

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Copyright information

© THE MINERALS, METALS & MATERIALS SOCIETY and ASM INTERNATIONAL 2009

Authors and Affiliations

  1. 1.Department of Materials Science and MetallurgyUniversity of CambridgeCambridgeUK

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