St Barbara’s Leonora operations in Western Australia have recorded below-expectation figures of 34,078 ounces of gold for the September quarter.
This was down from the 50,506 oz delivered in the previous period.
While the company had anticipated a softer result, the outcome was still disappointing, with gold production primarily impacted by lower than expected underground mining equipment availability and utilisation stemming from continued shortages in skilled maintenance staff at the Gwalia mine.
It said that consistent with the experience of the industry in WA, the staff problems drove lower than expected availability in underground equipment, impacting stope drilling, stope production and underground development rates.
Notwithstanding this, mining service provider Macmahon had helped to fill most of the vacant maintenance roles by the end of the quarter, with the team now expected to make inroads into the maintenance backlog over the coming quarters.
With staff shortages not materially extending to equipment operators, an additional long hole drill and two additional trucks were brought to site to temporarily ameliorate low equipment availability.
While gold grade across individual stopes does vary despite overall reliable grade reconciliation, St Barbara also noted the underperformance of two stopes in late September was not up to par and contributed to the overall lower gold output, which in turn contributed to higher than expected AISC at $2487/oz.
The Zoroastrian underground mine in the region remains on track to commence construction in Q3 FY23 with first production expected in Q1 FY24. It is expected to produce 300kt of ore at approximately 3 grams per tonne in its first year of production, with ore volumes expected to increase to 400 kilotonnes in its second year.
Stemming from the results, St Barbara has decided to defer the following capital expenditure for at least 12 months:
Leonora processing plant expansion to 2.1mtpa
Refractory ore circuit upgrade at Leonora processing plant
Construction of Aphrodite mine at Leonora
For the next financial year, St Barbara has set a production guidance of between 260-290koz, at an AISC of between $2250-$2500/oz.