Wetting behaviour of Cu based alloys on spinel substrates in pyrometallurgical context

Abstract

Metal droplet losses in slags are an important issue in copper industry. One significant aspect that promotes the entrainment of metal droplets in the slag is their attachment to spinel solids. In the present study, the wetting behaviour of copper alloys on spinel substrates has been investigated in the presence and absence of a slag phase. At first, the attachment was investigated using a synthetic slag containing spinel particles. Microstructural analysis of quenched slag reveals the presence of microdroplets sticking onto a surface of the spinel particles. Second, the metal–spinel interaction was investigated using the sessile drop technique. Wetting angle measurements were performed between Cu–Ag alloys and MgAl₂O₄ substrates. A non-wetting behaviour between the alloys and substrates was observed. The results suggest that the oxygen partial pressure and the amount of Ag in the alloy both influence the wetting behaviour.

Keywords:

• Metal entrainment
• Slag
• Spinel
• Copper
• Wetting

Acknowledgements

The authors wish to thank the Agency for Innovation by Science and Technology in Flanders (IWT, project no. 110541) and Umicore for its financial support. In particular, M. van Camp, L. Coeck, S. Bodvin, K. van Ostaeyen, E. Boydens, A. van Gool and the technical staff of Umicore R&D are thanked for their support with the experiments and characterisation. Dr R. Mukhlis, Mr S. Ahmad and Dr A. Khaliq are thanked for the help with performing the sessile drop experiments. K. Vanmeensel wants to thank the Research Fund Flanders (FWO) for his postdoctoral fellowship.