JOHANNESBURG (miningweekly.com) – Aim-listed Mwana Africa on Wednesday said production at plant processing operations at the Freda Rebecca mine, in Zimbabwe, had restarted, with 50% of production to be restored by the end of this month.

The company last week halted plant processing operations at the gold mine, following the rupture of a leach tank and its collapse onto a second tank.

This caused structural damage to both tanks, as well as led to the discharge of leach tank contents onto the ground surrounding the tanks beyond the bunded containment area.

Effluent had discharged into the mine's drainage canal, resulting in elevated cyanide levels from normal yellow discharge permit levels to red permit levels; however, discharge levels had now been returned to normal operating limits.

Containment of the leach tank contents had been completed and Freda Rebecca management, working in conjunction with the local Environmental Management Agency (EMA), continued to monitor discharge levels in the mine drainage canal.

The EMA had levied a fine of $5 000 on the mine for the discharge of material in breach of its permits.

Mine management expected to complete the clean-up of spillage from the drainage canal by the end of February 20.

Meanwhile, the Mines Inspectorate has completed its site investigation and had given permission to start work to remove damaged structures associated with the failure of tank three. 

This would allow mine personnel to start modifications that would lead to the recommissioning of leach tank one and the start of repairs to leach tank two.

The mine was investigating the cause of the tank collapse and was assessing the integrity of the other tanks and steelworks, Mwana noted in a statement.

Production had restarted on a reduced throughput basis and would increase as tank one was brought back on line. 

Management expected to maintain the 50% production level through March and was targeting full production to be restored by end-March.

The incident would affect production levels in the short term, with gold output for the 12 months to end March 2013, to be 63 000 oz.

Meanwhile, Mwana said the five employees injured in the incident had been discharged from hospital, with four having returned to normal duties, while the fifth, who was treated for a fractured ankle, was being treated as an out patient at the mine clinic.