JOHANNESBURG (miningweekly.com) – Gold mineral reserves at dual-listed miner Sibanye Gold’s operations have increased from 17.8-million ounces in December 2013 to 19.9-million ounces in December 2014, following the completion of prefeasibility studies on below infrastructure “drop-down projects”.

This 12% increase primarily stemmed from an additional 1.7-mlilion ounces of gold mineral reserves being declared at the miner’s Kloof 4 and Driefontein 5 shafts.

Sibanye CEO Neal Froneman said it was “extremely pleasing” to see the company’s operating strategy taking effect. “Significant improvements in the quality of mining and cost control at our operations, in the last two years, have facilitated a further increase in our mineral reserve base at our key operations,” he added.

Further, the company declared a maiden gold mineral resource of 8.9-million ounces at its Burnstone project, following significant revision of the available data and geological model.

Definitive feasibility studies for these projects were in progress and would be completed during 2015.

An additional one-million ounces from “secondary reefs” and “white areas” were also declared at the Kloof and Driefontein operations.

OTHER PROJECTS
Since acquiring Witwatersrand Consolidated Gold Resources (Wits Gold) in May 2014, Sibanye has thoroughly reviewed the geological and life-of-mine models of the De-Bron Merriespruit, Bloemhoek, Beisa North, Hakkies and Robijn projects in the Southern Free State and reestimated the mineral resources.

At the De-Bron Merriespruit project, the application of Sibanye’s resource estimation protocols and procedures resulted in gold mineral resources declining from 10.9-million ounces to four-million ounces.

Gold mineral reserves also declined from 3.1-million ounces to 2.1-million ounces. Based on the original feasibility study, previously conducted by Royal HaskoningDHV in 2013 and  was modified to take additional information into account, Sibanye intended to undertake a full review of this feasibility study with a view to improving the efficiency of any potential synergies with the Beatrix operations.

New geological models, incorporating borehole data from Wits Gold and Beatrix resulted in gold mineral resources decreasing from 14-million ounces to 4.3-million ounces. 

Meanwhile, the group would review the economic viability of accessing part of the Bloemhoek resource through the existing Beatrix underground infrastructure. No gold mineral reserves would be declared on the Bloemhoek project until these studies had been completed.

Sibanye also successfully started with uranium production at its Cooke operation during 2014.

The additional information derived during mining, combined with revised uranium mineral resource estimates resulted in uranium mineral resources and reserves increasing at the Cooke 1 to 3 operations.

At Cooke 4, uranium mineral reserves were negatively impacted owing to a reduction in ore reserve development arising from the Section 189 process. This would be reconsidered subject to ongoing operational profitability. The uranium mineral resources contained at Beatrix’s Beisa project increased marginally to 27-million pounds.

The application of Sibanye’s mineral resource estimation and declaration protocols resulted in a decrease in the uranium mineral resource at Beisa North from 47.8-million pounds to 35.4-million pounds.