First Quantum on track with Bwana Mkubwa

Mid-tier copper miner First Quantum Minerals (FM-T) has completed the first phase of an expansion program at its Bwana Mkubwa solvent extraction-electrowinning plant in Zambia.

The company has added new crushing, milling and pre-leach filtration facilities while constructing a second sulphuric acid plant. Acid production has since increased to 420 tonnes daily, or 145,000 tonnes annually.

First Quantum is working on the existing leach, filtration, solvent extraction-electrowinning facilities, which it expects to have expanded by November. Thereafter, annual cathode production at the plant should triple to 30,000 tonnes.

First Quantum began the expansion program after quadrupling the size of the Lonshi copper deposit, which sits in the Democratic Republic of Congo, about 35 km to the east. Resources are pegged at 5.1 million tonnes grading 5.75% copper.

The estimate is based on a 2% cutoff grade and 138 drill holes totalling 5,474 metres. Drilling includes a mixture of 10 core, 91 reverse-circulation and 37 air-blast holes.

The mineralization, in the same Roan clastic rocks that play host to most of the Zambian Copper Belt’s deposits, is about 15 metres thick and 800 metres long and dips gently to the east. It extends to 65 metres below surface, where it remains open. The deposit is open along strike as well.

Open-pit mining began last fall, and 335,000 tonnes are stockpiled. The material averages 5% copper and will eventually be mixed with the tailings currently processed at Bwana Mkubwa.

Drilling is also under way to test mineralized projections along strike and downdip, between 65 and 140 metres below surface. About 3,200 metres are planned in all.

In addition to Bwana Mkubwa, First Quantum owns a 44% interest in the Nkana and Mufulira mining and milling copper-cobalt complexes, also in Zambia. Although their combined production exceeds Bwana Mkubwa, they are not as profitable.

First Quantum also owns the Kansanshi copper deposit, which lies northwest of the mines, near the border. A feasibility study is determining the economic viability of mining the deposit, which hosts a near-surface resource of 267 million tonnes grading 1.28% copper and 0.16 gram gold per tonne.

GRD Minproc of Australia is managing the study.