Spinel synthesis from aluminium dross

Abstract

It is believed that aluminium recycling is going to become the main route of aluminium production in future. The secondary aluminium dross produced during aluminium remelting contains large amounts of salts and oxides. In recent years, various techniques were developed to recycle the dross in order to obtain the valuable materials in it. In this paper, spinel has been successfully synthesised from aluminium dross. After leaching for 1 h (the ratio of solid/liquid was 1∶50 at 20°C) with water, the salts KCl and NaCl were almost removed off from the dross. The temperature effect on the spinel synthesis was investigated in detail using the traditional solid phase sintering method. It was found that with increasing temperature, the spinel and Al₂O₃ became the main phases in the final products.