PERTH (miningweekly.com) – Uranium miner Energy Resources of Australia (ERA) has reported a 20% quarter-on-quarter production decline during the three months to June, owing to a planned mill shutdown.

The company produced 390 t of uranium oxide (U₃O₈) during the quarter under review, compared with 489 t U₃O₈ in the previous quarter, taking its interim production to 879 t.

ERA reported on Friday that progressive rehabilitation of the Ranger project area, in the Northern Territory, continued during the quarter, with the dredging and maintenance vessels designed to transfer tailings from the tailings storage facility to Pit 3 for final deposition, having been transported to the mine site. Commissioning of these vessels was scheduled for the September quarter.

During the quarter, ERA also took the decision not to proceed with the final feasibility study on the Ranger 3 Deeps underground mine, citing economic challenges and uncertain market conditions.

The Ranger 3 Deeps project considered the development of an underground mine to recover uranium from the Ranger 3 Deeps mineral resource, with most of the mining occurring between 200 m and 500 m below the ground.

It was estimated that the mine would run for a period of five years, and first production had initially been targeted for late 2015, pending board and regulatory approval.

Despite taking a decision not to proceed with the project, ERA on Friday updated the Ranger 3 Deeps mineral resource as part of the prefeasibility study.

The resource was now estimated to host some 19.58-million tonnes of ore, grading 0.224% U₃O₈, for 43 858 t of U₃O₈. This was compared with the previous estimate of 12.2-million tonnes, containing some 34 761 t of U₃O_8.

ERA has meanwhile started discussions with representatives of the Traditional Owners and the commonwealth government regarding a possible extension to the Ranger Authority. The company would also continue to conserve cash until it had greater certainty about the authority extension, which would allow ERA to revisit the project’s economics over time.