Experimental Measurements of Slag/Matte/Metal/Tridymite Phase Equilibria in the Cu-Fe-O-S-Si System at 1200ºC

ABSTRACT

An experimental study has been carried out to determine the compositions of the slag/matte/metal/tridymite phases in equilibrium in the Cu-Fe-O-S-Si system at 1200℃. The measurements covered the full range of matte compositions from copper-free mattes to white metal, i.e. from 0 to 80 wt% of copper in matte. The research methodology involved high-temperature equilibration, quenching of the samples and accurate measurement of the phase compositions by electron probe X-ray microanalysis. The oxygen concentrations in mattes were directly measured using the EPMA. A comprehensive set of experimental equilibrium data has been obtained for coexisting matte, slag, Cu-Fe metal alloy and Fe-Cu metal alloy phases. It has been shown that solid iron-copper alloys were present at matte grades below 56 wt% Cu, while liquid copper-iron alloys were formed for matte grades higher than 56 wt% Cu. The experimental measurements have been compared with data reported in the literature and the trends calculated using the thermodynamic model descriptions of the system.

KEYWORDS:

• Copper smelting
• copper recycling
• Cu–Fe–O–S–Si system
• copper losses
• low matte grades

Acknowledgments

The authors would like to thank Australian Research Council Linkage program, Altonorte Glencore, Atlantic Copper, Aurubis, BHP Billiton Olympic Dam Corporation, Kazzinc Glencore, PASAR Glencore, Outotec Oy (Espoo), Anglo American Platinum, Penoles, Umicore, and Kennecott Rio Tinto for the financial and technical support for this study. The authors would like to thank the staff of the Centre for Microscopy and Microanalysis, University of Queensland for technical support.

Disclosure statement

The authors declare that they have no known competing financial instersts or personal relationships that could have appeared to influence the work reported in this paper.