Cyclical vacuum chlorination processes, including lithium extraction

Abstract From the Canadian patent

Cyclical batch processes for halogenation such as chlorination, of minerals , in a fixed bed (12 42, 62, 82) using a plurality of cycles which include the steps of at least partially evacuating the bed charging the bed (12, 42, 62, 82) with reactant gas maintaining the reactant gas in the bed (12 42, 62, 82) for a predetermined time, and exhausting reaction products under vacuum. Also disclosed is the chlorination of spodumene in its beta crystalline form produced by calcining spodumene in its naturally occurring alpha crystalline form to preferentially extract lithium as lithium chloride.