JOHANNESBURG (miningweekly.com) – A definitive feasibility study (DFS) into the first phase of Ivanhoe Mines’ Platreef project has confirmed the technical viability of what the company expects to be the world’s lowest-cost and one of the world’s largest, single primary producers of platinum-group metals.

The project, which contains the Flatreef deposit, 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.

The 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 noted on Monday that it had received expressions of interest for about $900-million of the targeted $1-billion in project financing.

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.

“Platreef is a massive, high-grade, long-life and tier one deposit that will produce a suite of vital metals, many of which are essential to sustain our urbanising planet. The nickel and copper by-products are essential in the electric car revolution and the platinum and palladium are equally vital for hydrogen fuel cell technology and catalytic converters to clean the air.

“We now have a clear and defined path forward to initial production and subsequent phases of development. We are confident that the Platreef project will benefit all of our stakeholders, including the 20 local communities that are our equity partners, for generations to come,” Ivanhoe executive chairperson Robert Friedland commented.

Platreef will be mined using mechanised methods, including long-hole stoping and drift-and-fill.

Primary access to the mine will be by way of a 1 104-m-deep, 10-m-diameter production shaft (Shaft 2), while secondary access will be by way of a 980-m-deep, 7.25-m-diameter ventilation shaft (Shaft 1), which is under construction.

The sinking of Shaft 1 continues to advance at a rate of 45 m to 50 m a month and has reached a depth of 450 m below surface. The shaft is expected to reach its final depth in 2018.

Early works surface construction for Shaft 2 had begun in late May and is expected to be completed within a period of about 12 months.