Energy Resources of Australia (ERA) announced in early June that it is not proceeding to a final feasibility study of its proposed Ranger 3 Deeps underground mine at its Ranger mine in Australia’s Northern Territory. Open-pit mining ended at the Ranger mine in 2012, and ERA has been processing stockpiled ore since that time.

In 2014, ERA completed a 2,710-m exploration decline to access Ranger 3 Deeps mineralization and also completed a prefeasibility study of the project. A total of 47,000 m of close-spaced exploration drilling was completed in parallel with the decline construction program.

On July 10, ERA reported an updated resource estimate for Ranger 3 Deeps of 19.58-million mt of ore, grading 0.224% U3O8, equating to 43,858 mt of contained U3O8. The previous estimate had been 12.2-million mt, grading 0.285% U3O8 and containing 34,761 mt of U3O8.

ERA said its decision not to proceed to a final feasibility study was driven by two key factors. First, the uranium market has not improved as the company had previously expected, and there is uncertainty regarding the market’s direction. Second, the prefeasibility study demonstrated that the economics of the project would require operations to extend beyond the current “Ranger Authority” (its operating license), which expires in 2021. ERA has initiated discussions with relevant authorities regarding a possible extension of the “Ranger Authority,” but such an extension is not assured.

ERA is 68.4% owned by Rio Tinto. In a separate announcement, Rio Tinto said it agreed with ERA’s decision not proceed to a final feasibility study and that, “after careful consideration, Rio Tinto has determined that it does not support any further study or the future development of Ranger 3 Deeps due to the project’s economic challenges.”

ERA’s Ranger operations produced 1,165 mt of U3O8 processing stockpiled ore in 2014, down from 2,960 mt in 2013. Production during the first half of 2015 totaled 879 mt.