DFS, page-317

JSB, up until Tesla came on the scene Lithium was in an oversupply situation, although AJM have had the lease since 2011 it wasn't considered worth focusing on as the big three lithium producers has total control of the market. AJM, until 2015, were mainly focused on their Coal and iron ore interests, the sale of their 25% interest in Atlas's iron ore project as well as the curtailment of the coal saw the need to commence action on the lithium.
Of interest the main use of Lithium 30 years ago was in the nuclear weapons where it was used as a bomb trigger. Within the USA until the late 80's lithium was a controlled strategic metal set aside for nuclear bombs.