Mining Weekly

Diversified miner Vedanta Resources subsidiary Zinc International has committed more than 80% of the $400-million capital expenditure (capex) for the first phase of the Gamsberg zinc project, in the Northern Cape.

The first phase of the project is expected to have a mine life of 13 years, replacing the production lost by the closure of the Lisheen mine, in Ireland, and restoring Zinc International’s volumes to more than 300 000 t/y.

Mining and milling at Lisheen was concluded in December 2015 after 17 years of operation; the mine is currently in closure mode.

Prestart activities and waste stripping at Gasmberg are progressing well, with more than 25-million tonnes of the 65-million to 70-million tonnes of waste rock excavated.

Of the estimated peak of 1 500 jobs to be created during construction, more than 1 100 jobs had already been filled on site, Vedanta Zinc projects VP Satish Kumar told Mining Weekly during a site visit to the project earlier this month.

“Of the 1 153 employees on site last week, more than 58% came from the surrounding labour-sending areas,” he added.

When fully operational, the mine will permanently employ between 850 and 900 people.

The first phase will comprise an openpit mine and a concentrator plant with an ore feed rate of four-million tonnes a year. It will also comprise associated infrastructure, including a tailings dam, a waste rock dump and stockpiles, offices and workshops, a power transmission line from the Aggeneys substation to Gamsberg, a water pipeline and an access road from the N14 to Gamsberg, as well as 300 to 350 housing units.

One of the largest civil cement pours occurred at Gamsberg earlier this month, with about 760 m3 of concrete poured over a 24-hour to 30-hour period for the raft foundation of the semiautogenous grinding mill at the concentrator plant.

The concentrator is expected to produce about 250 000 t/y of zinc metal in concentrate.

Installation of the high-density polyethylene lining of the tailings storage facility started in July and was well under way, Kumar said, noting that the facility would require about 110 ha of lining.

Construction of the tailings storage facility is expected to be completed in the first quarter of 2018.

Further, construction of the water pipeline, which will run for almost 38 km from the Orange river water offtake, in Pella, in the Northern Cape, to the mine, is under way. Public water board Sedibeng will operate the pipeline.

Meanwhile, all major orders for the integrated process plant, water and power, mining and other prestart activities had been placed, the company reported last month.

Manufacturing of critical machinery, such as the mills, the crusher and transformers, is under way, with major contractors, such as Aveng Moolmans, ELB Group and Liviero Civils, mobilised to site. Site activities, including civil works, power lines and water lines, are also under way.

The project remains on schedule to achieve the first production target in mid-2018, with full production expected in 9 to 12 months.