A novel process to extract high purity alumina from kaolin clay

The recovery of alumina from kaolin clay presents a number of challenges and opportunities. Kaolin clay is ahydrated silica-aluminate mineral that occurs in deposit together with other metals such as iron and rare earthmetals. There are several large deposits of this kind in Canada that are not utilized due to the processingchallenges. The vast majority of the worlds' alumina is produced from bauxite ore using the Bayer Process andis imported to countries like Canada for conversion to aluminum. Development of a viable process to extractalumina, and potentially other metals, from clay deposits in Nova Scotia and in Canada presents an opportunityto secure a domestic supply of the worlds second most important metal.In this research project, AlNova will work together with Dr. Amyl Ghanem to develop methods of aluminaextraction from clay deposits currently existing in Nova Scotia. A number of acids can be used to solubilizethe alumina from kaolin clay and separate it from the insoluble silica portion. The main issues in this extractionthat will be addressed by this research are 1) optimization of conditions for acid leaching of metal ions fromclay and 2) the selective separation of Al 3+ and Fe 3+ from leachate using pH specific liquid-liquid extractionand 3) recovery and recycling of leaching and extraction fluids. The methodology of this research will firstfocus on bench scale testing of acid leaching of the clay followed by extraction of the acid leachate.