Name and Location
Kipushi zinc-copper mine redevelopment project, Democratic Republic of Congo.

Client
The project is operated by Kipushi Corporation, a joint venture between Ivanhoe Mines (68%) and State-owned mining company Gécamines (32%).

Project Description
A preliminary economic assessment (PEA) of the project focuses on the mining of Kipushi’s Big Zinc zone, which has an estimated 10.2-million tonnes of measured and indicated mineral resources grading 34.9% zinc.

Life-of-mine average planned zinc concentrate production is estimated at 530 000 dry tonnes a year, with a concentrate grade of 53% zinc. This is expected to rank Kipushi, once in production, among the world’s major zinc mines.

The planned mining method is a combination of sublevel open stoping (SLOS), pillar retreat and cut-and-fill methods at a steady-state mining rate of 1.1-million tonnes.

The PEA envisages the primary mining method for the Big Zinc zone being SLOS, with cemented rock backfill. The crown pillars are expected to be mined once adjacent stopes are backfilled using a pillar retreat mining method. The Big Zinc zone is expected to be accessed using the existing decline and without significant new development. The main levels are planned to be at 60 m vertical intervals, with sublevels at 30 m intervals.

The cut-and-fill mining method has been identified to extract the copper zone outside the Big Zinc zone – mining occurs in horizontal slices, with the blasted copper material removed from the stopes, then crushed underground and sold at the mine gate.

The planned process plant in the PEA is a dense-media separation plant, which is expected to include crushing, screening, heavy-liquid separation and spirals to produce a high-grade zinc concentrate.

The project is expected to leverage existing surface and underground infrastructure to significantly lower the redevelopment capital, compared with a greenfield development project, as well as the time required to reinstate production.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at an 8% real discount rate, of $759-million and an internal rate of return of 36.4%, with a pretax project payback period of 2.1 years.

Value
Preproduction capital, including contingency, is estimated at $409-million.

Duration
None stated.

Latest Developments
Ivanhoe Mines is on track with the modernisation and upgrading of the Kipushi zinc/copper mine, having re-established clear and safe access to all areas of the main underground workings, the company has stated.

Kipushi Corporation has upgraded the operating shafts, winders and underground infrastructure – which are expected to serve as alternate personnel and material shafts, as well as a second egress route from the mine at the Cascade section of the mine. A new high-volume ventilation fan has also been installed on surface at Shaft 4 to provide fresh air for the underground workings.

The main production shaft for Kipushi, Shaft 5, is being upgraded and recommissioned. The main personnel and material winder has been upgraded and modernised to meet western industry standards and safety criteria, and new cages will be installed in 2017. The rock-hoisting winder, which will have a potential hoisting capacity of 1.8-million tonnes a year, is being upgraded and is expected to be fully operational in late 2017.

Ivanhoe has advised that the critical path for the redevelopment of the mine runs through the upgrading of the Shaft 5 rock-hoisting winder, as well as the recommissioning of the main pumping station at Shaft 5, the underground crusher at the bottom of Shaft 5, the Shaft 5 rock load-out facilities and the restoration of the main haulage way on the 1 150 m level between the Big Zinc access decline and Shaft 5.

Shaft 5, which is planned to be the mine’s main production shaft, is 8 m in diameter, 1 240 m deep and about 1.5 m from the planned main mining area. The rock hoist and load-out system will be upgraded to western industry standards during 2017 to fully restore the shaft’s hoisting capacity. Shaft 5 provides the primary access to the lower levels of the mine, including the Big Zinc deposit, through the 1 150 m haulage level and underground ramp decline.

The planned primary mining method for the Big Zinc deposit in the PEA and prefeasibility study is sublevel open stoping, with cemented backfill. The crown pillars are expected to be mined once adjoining stopes are backfilled using a pillar-retreat mining method.

A PFS is currently under way to refine the findings of the PEA and optimise the mine’s redevelopment schedule, life-of-mine operating costs and the initial capital costs required to bring the mine back into production. Ivanhoe expects to complete the PFS in the second quarter of 2017.
 
Key Contracts and Suppliers
OreWin, and the MSA Group (PEA).

On Budget and on Time?
Too early to state.

Contact Details for Project Information
Ivanhoe Mines, Jeremy Michaels, tel +27 11 088 4300 or email jeremy.michaels@ivanplats.com.