JOHANNESBURG (miningweekly.com) – Multicommodity miner Mwana Africa lifted gold production from its Freda Rebecca mine, in Zimbabwe, by 6% to 16 985 oz in the quarter ended June 30, benefiting from a 37% increase in tons mined to 316 151 t and an 11% improvement in feed grade to 2.03 g/t, it said on Tuesday.

Conversely, tons milled at the operation decreased by 0.3% to 293 759 t on the prior quarter, mainly owing to a 1% decrease in mill running time, which was hampered by the relining of the grates for both mills and the replacement of the No 1 mill's trunnion liner.

Cash costs, at $930/oz, were down 25% quarter-on-quarter, mainly owing to an increase in ounces produced and a 5% reduction in operating costs.

All-in sustaining costs (AISC) were, meanwhile, cut by 24% to $1 093/oz from $1 429/oz in the prior quarter, Mwana chairperson Yat Hoi Ning said.

“At Freda Rebecca, the average gold price received was $1 186/oz – its lowest in several quarters.

“[However], we countered the adverse effect by producing more gold, which, in turn, contributed to a significantly lower cash cost and AISC. This means the mine remains operationally profitable and will be maintained in that state,” he outlined.

Elsewhere in Zimbabwe, production from Mwana’s Trojan nickel mine dropped by 34% to 1 349 t, compared with the 2 032 t produced in the prior quarter, primarily owing to a reduction in average headgrade and recoveries.

Headgrade, at 1.2%, dropped 26% quarter-on-quarter as a result of the lower production of massive ores areas, while overall nickel recovery dipped 3% to 84%.

The average net realised nickel-in-concentrate price also lost traction, dropping 11% to $8 461/t, while nickel sales, at 1 267 t, narrowed by 39% owing to lower production.

Actual cash costs of nickel-in-concentrate rose 29% to $8 901/t quarter-on-quarter, while the actual AISC of nickel-in-concentrate rose by 35% to $9 736/t in the quarter under review as a result of lower production and the refurbishment of equipment.

Hoi Ning added that the operation continued to be hampered by the continued upgrading of equipment.

“Underground development work has proceeded more slowly than had been planned, but with the re-deep project now scheduled for completion in October, the current financial year's second half should see considerable operating improvements that will be followed by the benefits of the smelter restart,” he advised.

Work on the restart was proceeding on schedule and, when completed, would likely result in the company receiving “enhanced” prices for the nickel contained in its products.

In South Africa, throughput of Marsfontein fine residue tailings at Mwana’s Klipspringer diamond mine fell to 38 760 t, which was 10% lower quarter-on-quarter.

Headgrade improved by 8% to 44 carats per hundred tonnes as mining continued through a transition zone so as to access higher-grade material.

Diamond sales fell by 45% quarter-on-quarter, while the price received for fine diamonds produced at the mine fell by 7% quarter-on-quarter, which Mwana noted was in line with market conditions, which were expected to remain constrained.

“Revenues at Klipspringer were affected by the lower diamond prices that have been affecting all diamond producers. The processing plant, which recovers gems from old slimes tailings, suffered temporary technical problems, which lowered production, but this is expected to be resolved in the current quarter,” Hoi Ning said.

Meanwhile, in line with the company's determination to limit expenditure, the group limited its prospecting work with its partners in the Democratic Republic of the Congo (DRC) over the quarter.

“[Activity in the DRC] has been restricted largely to fieldwork designed to locate further exploration targets and to improve our knowledge of those already delineated.

“Overall costs were tightly controlled in the quarter under review and this will continue well into the future. It is far from clear when commodity prices will improve from their currently depressed levels, but our operations remain cashflow positive and our capital programmes will remain on track,” he concluded.