Flotation separation of vanadium-bearing clays, kerogen, and calcite in the Julia Creek oil shales

• Key processing challenge is separating valuable clays and oils from calcite gangue. • Detailed review of flotation chemistry for kerogen, calcite, and montmorillonite. • Pre-flotation of native carbon necessary before flotation of calcite and clays. • Separation of calcite and clays complicated by reagent and solution chemistry. • Proposed reverse and direct flotation pathways for shale and coquina regions. The Julia Creek oil shales in Queensland, Australia, is one of the largest carboniferous vanadium deposits in the world, with inferred resources of over 2,400 Mt at grades of 0.31% V 2 O 5 . The increasing demand for vanadium as a vital component for energy storage technologies represents a large untapped opportunity to supply the global need for vanadium. The Julia Creek deposit consists of shale regions and carbonate-rich coquina regions, and contains high-value kerogen in addition to vanadium that is primarily hosted in the clays. The key processing challenge is in the separation of the hydrocarbon oils and the vanadium-bearing clays from the calcite gangue, and the aim of this review is to examine the application of froth flotation as a possible approach. This review will first detail the mineralogical aspects of the Julia Creek oil shales, followed by a comprehensive overview of flotation practices for the separation of kerogen, calcite, and clay minerals. The focus of the discussion will be on the reagent chemistries of the collector and depressants used in flotation, as well as the operating conditions for the flotation recovery or rejection of the three components, while also highlighting potential challenges to their implementation for the Julia Creek deposit. Subsequently, the review will assess flotation pathways for the processing of the different shales and coquina regions.