JOHANNESBURG (miningweekly.com) – Mwana Africa has reported a 36.8% increase in gold production from its Freda Rebecca mine, in Zimbabwe, to 65 350 oz for the quarter ended March 31, 2013.

This was despite production in the March quarter being adversely affected by a disruption caused to the processing circuit as a result of the failure of leach tank three and associated damage to leach tank two in February.

Following the incident, steps were taken to minimise the disruption; however, the net effect on the circuit resulted in reduced milling throughput and reduced metallurgical recoveries for the quarter.

Underground operations were scaled back during the quarter to match a reduced milling profile, which drove cash costs higher as a result of less ounces having been produced. 

Cash costs for the year ended March, were $883/oz, compared with $1 021/oz for the previous year, representing a decrease of 13.5%.

Mwana announced in January that the construction of a tailings retreatment pilot plant had started, which would be used to test the viability of producing gold from the extensive tailings dumps at Freda Rebecca. 

All subcontractors had been appointed and construction was progressing on schedule, with commissioning expected to be completed in the September quarter.

Meanwhile, exploration drilling at the Zani-Kodo joint venture continued, indicating an increased combined Joint Ore Reserves Committee-compliant resource of 2.62-million ounces – an increase of some 30% since February 2012.

In addition, the refurbishment programme for the surface milling, flotation, tailings and concentrate handling facilities at the Trojan nickel resource progressed well in the March quarter, with the processing plant completed at the end of the month.

Milled ore tonnages for February and March were 60 555 t, with the first shipment of nickel concentrate dispatched from Trojan on April 15.

The total nickel resource for the Trojan nickel mine now stood at 114 952 t.