Zinc
Vedanta Zinc International

Vedanta Zinc International, a subsidiary of London-listed Vedanta Resources, has brought its mammoth US$400 million Greenfields Gamsberg zinc mine into production.

The development of this project has coincided at a time in the zinc market when prices are reaching multi-year highs, enabling the Gamsberg operation to take advantage of strong markets.

AUTHOR: Mining Review Africa's senior deputy editor, Chantelle Kotze.

Vedanta Zinc International (VZI)’s flagship Gamsberg project, which is said to be one of the world’s largest undeveloped zinc deposits, is located within the Black Mountain Mining Complex near Aggeneys in the Northern Cape.

It hosts 214 Mt of defined mineral resource, with an average grade of between 6 and 6.5% zinc.

This article first appeared in Mining Review Africa Issue 6 2018

In Phase 1, which has a life of mine of 13 years, 4 Mtpa of ore will be mined from Gamsberg’s open pit and 250 000 tpa of zinc in concentrate will be produced from its concentrator plant.

Since the first blast for Phase 1 in July 2015, pre-start mining activities have advanced according to schedule.

Completion in April 2017 of an access ramp – essential for waste pre-stripping to access the ore body for bulk mining – was the next significant milestone in Gamsberg’s development.

By June 2017, full waste pre-stripping of 3 Mtpm had been achieved and is expected to continue at this rate until the start of ore production.

As at April 2018, around 60 Mt of waste has been removed as part of the prestart mining and pre-stripping work programmes – which will see a total of 68 Mt of pre-strip waste rock being moved.

Construction of the concentrator plant and vital infrastructure for the overall project – including a power line, water pipeline and a high density polyethylene (HDPE)-lined tailings dam – peaked in the first quarter of CY2018 and overall construction activities were more than 85% complete by May 2018.

The water pipe line and power line are 100% complete, while the earthworks for the tailings dam are complete, and the installation of the HDPE lining is at more than 110 ha of the 117 ha total.

VZI is currently working on the cold commissioning of the concentrator plant in end of Q1 FY 2018-19 – which will become the largest single-stream zinc plant in the world.

“Once Gamsberg Phase 1 reaches full production – which is expected to be reached in nine to 12 months from first production – Phase 2 of Gamsberg could start as early as completion of Phase 1, depending on market conditions”, says Deshnee Naidoo, who has recently been appointed as Vedanta’s CEO: Africa Base Metals.

Naidoo is responsible not only for VZI in South Africa and Namibia but also now also for Konkola Copper Mines in Zambia, as well as Copper Mines of Tasmania.

Naidoo, who has led the development of the Gamsberg project since joining the company in 2014, goes on to explain that Phase 2 will see VZI mine 8 Mtpa of ore to produce 450 000 tpa of zinc in concentrate from one mega pit, which will result in the consolidation of all the pits mined in Phase 1.

This production level will ultimately be increased to 600 000 tpa in Phase 3.

But VZI’s vision does not start and end with bringing Gamsberg into production; the vision is much larger and entails the creation of a Southern African zinc cluster that would incorporate both Black Mountain Mining and the associated flagship Gamsberg project in the Northern Cape and the Namibia Zinc mining and refining operations in southern Namibia.

Integration through beneficiation

Coinciding with the second and third phases of the Gamsberg mine’s expansion plan, VZI announced in May 2018 that a feasibility study into the development and construction of a $700 - $800 million Zinc Smelter-Refinery Complex to process concentrates from its Gamsberg project had started.

The feasibility study will evaluate the infrastructural requirements of the complex.

“The establishment of the proposed beneficiation plant will make Gamsberg a fully integrated zinc production site, with the mine, concentrator and Smelter-Refinery Complex at single location, making it the first integrated zinc manufacturing facility in South Africa,” says Naidoo, who is fully aware of and passionately driven by the benefits that an integrated zinc plant will bring to the region from an economic perspective.

It is envisaged that the first phase of the Smelter-Refinery Complex will have a capacity of 250 000 tpa of finished zinc metal.

As the entire Gamsberg project has been developed in a modular fashion, so the Smelter-Refinery Complex could also be expanded to align with Gamsberg Phases 2 and 3.

Moreover, the feasibility study’s scope also includes a review of previous work undertaken into the possibility of developing a Southern African zinc cluster that would incorporate both Black Mountain Mining in South Africa and Skorpion Zinc in Namibia.

Back on the cards is the potential conversion of Skorpion Zinc’s 150 000 tpa refinery in Rosh Pinah, to co-treat sulphide and oxide concentrates from Gamsberg – a project that had  to be deferred following Skorpion’s Pit 112 extension.

Should the vision be realised, the Southern African zinc cluster would have the potential to be one of the world’s largest zinc supply regions, explains Naidoo.

Downstream beneficiation may triggering a wave of industrialisation

The expansion of Gamsberg into beneficiation streams has the potential to trigger a new wave of industrial and economic development the Northern Cape, which could provide additional opportunities for Vedanta Resources and others, in what is one of the least developed regions of South Africa.

There are opportunities for further value-adding zinc beneficiation (such as galvanising), the creation of a regional fertiliser industry considering that a zinc Smelter-Refinery will produce sulphuric acid as a by-product (given the presence of phosphates), the accelerated development of the agricultural industry, prospects for steel production (given the proximity of iron, zinc and manganese mining) and potential for the development of rail and other logistical links.

“The development of Gamsberg would just be the beginning in unlocking further opportunities in the region,” says Naidoo, adding that industrial development would need additional power resources in a region that has vast potential for solar energy, water supply and other economic and social infrastructure requirements.

These investment opportunities could be a game-changer for the Northern Cape region, and contribute to economic growth in South Africa as a whole.

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