Lithium developer Pilbara Minerals has seen a 136% increase in its total proved and probable ore reserve for its 100%-owned Pilgangoora lithium/tantalum project in Western Australia’s Pilbara region to 69.8-million tonnes, grading 1.26% lithium oxide (Li2O). This more-than-double upgrade was compared with the maiden ore reserve of 29.5-million tonnes, grading 1.3% Li2O, used to underpin the March prefeasibility study, following an expanded resources programme.