PERTH (miningweekly.com) – Gold miner Regis Resources has amended its full-year production guidance for its Duketon operations, in Western Australia, to between 300 000 oz and 340 000 oz, down from the previous estimate of between 340 000 oz and 380 000 oz, following a wall slip at the Rosemont main pit.

Group production for the full year is now expected to be between 420 000 oz and 475 000 oz, down from the previous estimate of between 460 000 oz and 515 000 oz.

All-in sustaining cost (AISC) guidance range for Duketon is now A$1 540/oz to A$1 610/oz, up from the previous estimate of between A$1 340/oz and A$1 410/oz and the company range is now A$1 425/oz to A$1 500/oz, compared with the previous estimate of between A$1 290/oz and A$1 365/oz.

Regis said on Monday that a lift in production in the second half of 2022 is expected due to increased mill feed grade at Moolart Well, increased mill feed grade and throughput at Garden Well, and increased underground mine grade at Rosemont.

The Rosemont main pit is approaching its final stages and is completion is planned for before the end of the June 22 quarter. Heavy rain earlier in January resulted in a rockfall event of approximately 800 t occurring. No personnel were in the pit at the time of the event and the incident occurred without injury or risk of injury.

However, due to the risks associated with continued mining, Regis took the decision to permanently stop all activity in Rosemont main pit. The pit was expected to deliver approximately 18 500 oz of high-grade ore at 2.6 g/t in 2022, after which the Rosemont main pit would be completed. Evaluations concluded that this high-grade ore can only practically be replaced in the mill feed by low-grade stockpiles for the remainder of 2022.

While these ounces no longer form part of the current production schedule, work is now underway to recover this material by mining from the existing development in the Rosemont main zone underground area.

Regis told shareholders that this rockfall event and its impact are confined to the Rosemont main pit and will have no negative impact on the ongoing operation of the Rosemont underground or Rosemont north pit.

Meanwhile, Regis on Monday reported gold production of 108 281 oz during the three months to December, at an AISC of A$1 530/oz. The Duketon operation produced 74 829 oz in the period under review, while the Tropicana mine delivered a further 33 453 oz.

Gold sales for the quarter reached A$313-million, at an average realised price of A$2 304/oz.

“The December quarter saw improved production on the prior quarter although slightly weaker than anticipated. Notwithstanding further expected increases in production over the second half of 2022, the impacts of last week’s unexpected geotechnical event, combined with other operational challenges and industry pressures, have resulted in us revising down our production guidance and increasing our cost guidance, for the full financial year,” said MD Jim Beyer.

“While disappointed with the commercial impacts of the recent geotechnical slip, we were pleased to see our geotechnical monitoring and safety management protocols ensured no people were harmed. This ongoing focus on safety is also reflected in our continuing excellent safety performance.

“It is satisfying to see the significant contribution that Tropicana is making to our company and to be part of the future at Tropicana that continues to unfold as we anticipated. Production rates are expected to lift later this calendar year on the path to return to previous production levels between 450 000 oz to 500 000 oz per annum,” Beyer added.

“Our preparations for and management of Covid related risks continue with the response plans for our operations constantly being assessed and modified for changing rules and conditions. The ongoing significant travel restrictions and general Covid impacts that Regis, and the entire Western Australia mining industry are experiencing, continue to present challenges and risks. We continue to work with our contractors and suppliers to develop and execute mitigation action plans.

“In other growth areas, development continued at our Garden Well South underground mine, with first stoping due to commence late in the June 2022 quarter. The new potential mining area under Garden Well Main pit continues to shape up well and we expect the results of a study later this quarter. Positive progress of the permitting process for McPhillamys continues, albeit frustratingly slowly.”