VANCOUVER (miningweekly.com) – Africa-focused megaproject developer Ivanhoe Mines has reached the 500-m level below surface, during construction of the first shaft of the Platreef platinum group meals (PGM) project, in South Africa's Limpopo province.

The 7.25-m-diameter Shaft 1, which is expected to reach the Flatreef mineralisation at a depth of about 783 m in the third quarter of next year, will be used for initial access to the Flatreef deposit and early underground development.

The shaft's final depth will reach 980 m below surface, with the first shaft station, completed in September at a depth of 450 m, to be used as an intermediate location for water pumping and shaft-cable termination. As shaft sinking progresses, a further three shaft stations will be developed at mine working depths of 750 m, 850 m and 950 m, Ivanhoe advised in a press release.

“Our continued development of shafts 1 and 2 will provide access to the Flatreef deposit and help to ensure that the project is able to meet the scheduled, first phase start-up of the underground mine and concentrator by 2022. Our team is dedicated to building a state-of-the-art mine that will produce metals that are essential to our urbanising planet," stated billionaire mining veteran and executive chairperson Robert Friedland.

Founder of Ivanhoe Mines, Friedland has a knack for finding mega deposits – most notably being involved with the Voisey's Bay nickel discovery in Canada, the discovery of a chain of copper, gold and silver deposits at Oyu Tolgoi (by Turquoise Hill Resources), in Mongolia’s South Gobi region and, more recently, the Kakula discovery, which forms part of the larger Kamoa project, in the Democratic Republic of Congo (DRC). Ivanhoe is also developing the substantial Kipushi zinc/copper mine in the DRC, which, based on the ‘Big Zinc’ zone, has average planned zinc concentrate output of 530 000 t/y, with a concentrate grade of 53% zinc over the project’s ten-year mine life. Once in production, Kipushi is expected to rank among the world's major zinc mines.

DEEPER UNDERGROUND
Work to sink Shaft 1 continues to advance at a rate of 40 m to 50 m a month. About 40% of Platreef’s shaft-sinking team is comprised of employees from local communities who had no previous mining experience. New employees received intensive, on-site training for underground mining and completed a workplace-safety induction programme, Ivanhoe advised.

Early-works surface construction for Shaft 2 started in May, with initial curtain grouting around the box cut. Further work focused on digging a surface box cut to a depth of about 29 m and construction of the concrete hitch for the 103-m-tall concrete headgear that will house the shaft’s permanent hoisting facilities and support the shaft collar. The early-works construction is expected to be completed in the third quarter of next year.

Shaft 2 will have an internal diameter of 10 m and the capacity to hoist six-million tonnes a year. The headgear design for the six-million-tonne-a-year permanent hoisting facility has been completed by South Africa-based Murray & Roberts Cementation.

The project is located on the northern limb of South Africa’s Bushveld Igneous Complex and will produce platinum, palladium, rhodium and gold (3PGE+Au), as well as nickel and copper.

The first phase of the project will entail a four-million-tonne-a-year operation, with possible expansions to eight-million and 12-million tonnes in two further stages.

A July definitive feasibility study (DFS) has estimated a preproduction capital requirement of about $1.5-billion for the first stage, which will produce about 476 000 oz/y of 3PGE+Au, 21-million pounds a year of nickel and 13-million pounds a year of copper.

Platreef will rank at the bottom of the cash-cost curve, at an estimated $351/oz of 3PGE+Au produced, net of by-products and including sustaining capital costs, and $326/oz before sustaining capital costs.

The DFS also estimates a net present value of $916-million and an after-tax internal rate of return of 14.2%; however, Ivanhoe expects the actual return to project equity owners to be higher as a result of the significant amount of project financing that is being raised.

Ivanhoe, which holds a 64% indirect interest in the Platreef project through its subsidiary Ivanplats, has, during this year, appointed two mine-financing institutions and three financial institutions to arrange the $1-billion in project financing for the development of Platreef.