Ivanhoe plans 'new era of production' for historic DRC mine

JOHANNESBURG (miningweekly.com) – TSX-listed Ivanhoe Mines has entered into discussions to start a “new era of production” at the historic Kipushi zinc-copper-silver-germanium mine, in the Democratic Republic of Congo (DRC), that could deliver one of the highest-grade major zinc mines worldwide.

Ivanhoe, which, in conjunction with its 32% joint venture (JV) partner State-owned miner Gécamines, recently upgraded Kipushi, is now planning to restore production, with the JV, the Kipushi Corporation, focusing initial mining on the Big Zinc deposit.

Negotiations are under way with Gécamines and DRC’s national railway company Société Nationale des Chemins de Fer du Congo (SNCC), along with potential project financiers, to advance agreements to launch the new era of commercial production, said Ivanhoe executive chairperson Robert Friedland.

Ivanhoe’s drilling has upgraded and expanded the Big Zinc deposit’s measured and indicated mineral resources to an estimated 10.2-million tonnes grading 34.9% zinc, 0.65% copper, 19 g/t silver and 51 g/t germanium, at a 7% zinc cutoff, containing an estimated 7.8-billion pounds of zinc.

Ivanhoe is progressing the prefeasibility study (PFS) to refine the findings of the 2016 preliminary economic assessment (PEA) and optimise the mine’s redevelopment schedule, life-of-mine operating costs and initial capital costs required to return the mine to production.

The PFS is focusing on the mining of the Big Zinc deposit.

“This exceptional grade is more than twice as high as the measured and indicated mineral resources of the world’s next-highest grade, major zinc project,” Friedland said.

Kipushi has several copper-rich zones that also contain silver, germanium and zinc in addition to the Big Zinc deposit.

Measured and indicated mineral resources contained in the copper-rich Série Récurrente zone, fault zone and fault zone splay total 1.63-million tonnes at grades of 4.01% copper, 2.87% zinc and 22 g/t silver, at a 1.5% copper cutoff, containing 144-million pounds of copper.

Inferred mineral resources in these zones total an additional 1.64-million tonnes at grades of 3.30% copper, 6.97% zinc and 19 g/t silver.

“Given the extremely high zinc grades at Kipushi, the mine has the potential to become one of the world’s largest and lowest-cost zinc producers, while also producing significant quantities of copper, silver and germanium.

“With the current, long-term, bullish market sentiment for zinc, we look forward to working with our partner, Gécamines, prospective project financiers and our team at Kipushi to fast-track completion of the remaining development at the mine,” Friedland commented.

Ivanhoe and SNCC are working on a new cooperation agreement to rehabilitate the inactive spur line that connects the Kipushi mine to the Congolese national railway and to the overall north-south rail
corridor that links the DRC copperbelt to the seaport at Durban, South Africa.

The parties are currently negotiating the details of an infrastructure financing agreement for the railway rehabilitation works and the terms of operation for the spur line.

“This cooperation on public infrastructure projects mirrors Ivanhoe Mines’ successful, ongoing partnership with the DRC’s State-owned power company La Société Nationale d’Electricité for the rehabilitation of three hydropower plants,” he said.

THE MINE REVIVAL
For nearly 70 years, Kipushi had produced 6.6-million tonnes of zinc and four-million tonnes of copper from 60-million tonnes of ore grading 11% zinc and about 7% copper.

Between 1956 and 1978, the mine had also produced 278 t of germanium and 12 673 t of lead.

“Most of Kipushi’s historical production was from the fault zone, a steeply dipping orebody rich in copper and zinc that initially was mined as an openpit,” explained Friedland.

However, the “founding era of mining” at Kipushi ended in 1993, when the mine was placed on care and maintenance owing to a combination of economic and political factors, until Ivanhoe bought a 68% stake in the project in 2011.

Kipushi Corporation then started modernising the mine’s underground infrastructure as part of preparations for the mine to resume commercial production.

The modernisation and upgrading of Kipushi’s surface infrastructure to handle and process Kipushi’s high-grade zinc and copper resources will become the near-term focus as the underground revamp nears completion.

The current mine redevelopment plan has a two-year construction period with quick ramp-up to a projected, steady-state, yearly production of 530 000 t of zinc concentrate.

The main production shaft, Shaft 5, at Kipushi has been upgraded and recommissioned, along with the main personnel and material winder.

The shaft’s 1.8-million-tonne-a-year rock-hoisting winder is also being upgraded and is expected to be fully operational by early next year.

Underground upgrading work also continued on the crusher and the rock load-out facilities at the bottom of Shaft 5, as well as the main haulage way on the 1 150 m level between the Big Zinc access decline and Shaft 5.

This work is expected to be completed before the end of the first quarter of 2018.

The Big Zinc deposit was expected to be accessed through the existing decline and without any significant new development, the company assured.

“The planned primary mining method for the Big Zinc deposit in the PEA and PFS is sublevel long hole, open stoping, with cemented backfill. The crown pillars are expected to be mined once adjacent stopes are backfilled using a pillar-retreat mining method,” Friedland commented.

FURTHER EXPLORATION
Meanwhile, Ivanhoe’s 41-hole, 6 500 m underground drilling programme at the mine is nearing completion.

The programme includes six metallurgical holes and 35 resource drill holes in the fault zone, the nord riche and southern zinc zones to expand and upgrade inferred resources to indicated resources.

Ivanhoe expects to issue an updated mineral resource estimate for Kipushi later this year once all the assays have been received from the drilling programme.