Concentration of Scandium during Processing the Distillate of Production of the Aluminum–Scandium Foundry Alloy

Abstract

The composition and characteristics of the sublimate of the aluminum–scandium Al–2%Sc master-alloy production are investigated using electron microscopy, electron probe microanalysis, X-ray phase analysis, and inductively coupled plasma emission spectroscopy. It is established that the sublimate consists of particles 1–5 μm in size by 60 %; the coarser of them have a shell, inside which, inclusions (segments, particles, pieces) of various phases are present. The sublimate consists of metal aluminum (~35 %), two modifications of aluminum fluoride (~57 % total), and the rest is corundum. The scandium content is 0,5–0,6 wt %. It is shown that the use of hydrometallurgic methods is reasonable for its processing. The method of preparing «rich» concentrate with 3–11 wt % Sc from this type of waste by the treatment of the sublimate with the 10-% caustic soda solution at 80 °C is proposed.