The Platreef Project is a Tier One discovery by Ivanhoe Mines’ geologists of platinum-group elements, nickel, copper and gold, which contains the Flatreef underground deposit, on the Bushveld’s Northern Limb.

"Completion of the Platreef preliminary economic assessment is another significant step in the progression of our plan to develop this remarkable discovery into a world-class, underground mine," said Mr. Friedland.

"We’re looking forward to working with all of our stakeholders to advance the Platreef Project to production, to create valued and skilled jobs and to significantly contribute to the socio-economic development of the people of area communities who will have a voice in decision making and a direct share in our success through our responsively structured, broad-based, black economic empowerment partner."

Highlights of the preliminary economic assessment (PEA):

Development of a large, mechanized, underground mine is planned through a phased approach.

Three run-of-mine production scenarios were examined – 4 million tonnes per year (Mtpa); a base case of 8 Mtpa; and 12 Mtpa.

An initial 4 Mtpa scenario would establish an operating platform.

Options available to accelerate expansions to the base-case 8 Mtpa and also the 12 Mtpa scenarios, as the market dictates.

Opportunities exist for additional phases of development beyond 12 Mtpa, subject to further study.

Key features of the 8 million tonnes/year base-case scenario include:

Base-case annual production target of 785,000 ounces of platinum, palladium, rhodium and gold. (At an expanded operating scenario of 12 million tonnes per year, the annual production target would be 1.1 million ounces of platinum, palladium, rhodium and gold (3PE+Au)).

Platreef, with the highest concentration of base metals among Africa’s platinum-group metals producers, would rank at the bottom of the cash-cost curve, at an estimated US$341 per ounce of 3PE+Au, net of by-products.

Estimated pre-production capital requirement of approximately US$1.7 billion, including US$381 million in contingencies.

After-tax Net Present Value of US$1.6 billion, at an 8% discount rate.

After-tax internal rate of return of 14.3%.

The PEA was prepared by report contributors OreWin Pty. Ltd.; AMEC E&C Services Inc.; SRK Consulting Inc.; Stantec Consulting International LLC; Metallicon Process Consulting (Pty.) Ltd.; and Geo Tail (Pty.) Limited. The full technical report will be filed on SEDAR at www.sedar.com and on the Ivanhoe Mines website at www.ivanhoemines.com within 45 days of the issuance of this news release.

The PEA includes an economic analysis that is based, in part, on Inferred Mineral Resources. Inferred Mineral Resources are considered too speculative geologically to have the economic considerations applied to them that would allow them to be categorized as Mineral Reserves, and there is no certainty that the results will be realized. Mineral Resources are not Mineral Reserves because they do not have demonstrated economic viability.

Phased approach to the development of a large, mechanized, underground mine

Ivanhoe’s plan for the Platreef Project considers three phases of potential development for an underground mine and the concentrator processing facility:

Phase 1 – 4 Mtpa mine and concentrator.

Phase 2 – 8 Mtpa mine and concentrator (base case).

Phase 3 – 12 Mtpa mine and concentrator.

The base case for the Platreef PEA analysis is the 8 Mtpa production scenario. The range of development scenarios and additional options for the Platreef Project are shown in Figure 1. The scenarios describe a staged approach, where there is opportunity to expand the operation depending on demand, smelting and refining capacity and capital availability. As Phase 1 is developed and placed into production, there is opportunity to modify and optimize the subsequent phases, allowing for changes to the timing or expansion capacity to suit the conditions at the time. Opportunities for additional expansion beyond Phase 3 may be available, but require additional investigation.

Phase 1 would include the construction of a concentrator and other associated infrastructure to establish an operating platform to support the start of production at a nominal plant capacity of 4 Mtpa by 2020. Phase 2 includes a ramp-up to a plant capacity of 8 Mtpa by 2024; Phase 3 envisages a further ramp-up to a steady-state plant capacity of 12 Mtpa by 2028.

Site preparation is underway for the sinking of the planned exploration shaft to obtain a bulk sample for metallurgical test work. This shaft would form an important part of a Phase 1 project. A Mining Right Application was filed with South Africa’s Department of Mineral Resources in June 2013 and is awaiting approval. When granted, it will permit Ivanhoe Mines to mine and process minerals from the mining area for an initial period of 30 years, which may be extended.

The capital and operating costs for the three phases have been estimated by independent technical consultants and have been included in the economic analysis reported in the PEA. This modular approach has the same underlying plan for the construction and operation of a concentrator processing facility for each phase. The planned rate of mine production will be optimized to supply the progressive expansion of processing capacity in the accompanying concentrator. Infrastructure constructed to support the mine also is common to all phases.

Positive preliminary economic analysis demonstrates Platreef’s exceptional economic potential

The economic analysis uses price assumptions of $8.35/lb nickel, $1,700/oz platinum, $820/oz palladium, $1,300/oz gold, $3.00/lb copper and $1,700/oz rhodium. The prices are based on a review of consensus price forecasts from financial institutions and similar studies that recently have been published.

The PEA includes an economic analysis that is based, in part, on Inferred Mineral Resources. Inferred Mineral Resources are considered too speculative geologically to have economic considerations applied to them that would allow them to be categorized as Mineral Reserves, and there is no certainty that the results will be realized. Mineral Resources are not Mineral Reserves because they do not have demonstrated economic viability.

The higher nickel and copper grades contribute to lower operating cash costs for the Northern Limb as illustrated by Figure 3. Among the current and future Northern Limb producers, Platreef’s potential US$341 per 3PE+Au ounce, (net of base-metal by-products), ranks at the bottom of the cash-cost curve.

Pre-feasibility study and development of bulk-sample shaft under way

Surface construction work is underway for Shaft #1, the 7.25-metre-diameter bulk-sample shaft. The vertical shaft is planned to be sunk to a depth below surface of 800 metres and enable the collection of a mineralized bulk sample, expected in the first half of 2016, to complete the company’s development assessment of the Flatreef. South Africa-based Aveng Mining, the sinking contractor for Shaft #1, is continuing surface preparation work at the site; excavation of the box-cut access has begun. Upgrading of hoisting equipment to be installed in the shaft headframe is underway; excavations for concrete foundations of the shaft collar and ventilation casing are scheduled to begin this month.

Shaft #1, including some initial lateral, underground development work, is expected to be fully funded from dedicated funds remaining in Ivanhoe’s treasury from the US$280 million received in 2011 for the sale of an 8% interest in the Platreef Project to the Japanese consortium of Itochu Corporation; ITC Platinum, an Itochu affiliate; Japan Oil, Gas and Metals National Corporation; and Japan Gas Corporation.

Ivanhoe will begin the design and engineering of Shaft #2, the main production shaft, in Q2 2014. This will enable the company to start Shaft #2 development works in Q1 2015, subject to necessary approvals and funding.

A pre-feasibility study (PFS) also is underway and completion is targeted for the second half of 2014. The PFS currently focuses on the initial 4 Mtpa Phase 1 production case, based on selling or tolling concentrate at local smelters. Studies will continue on the base case 8 Mtpa Phase 2 and 12 Mtpa Phase 3 production scenarios with the intention of presenting an integrated development plan for the project incorporating the Phase 1 PFS.

Platreef ownership interests

Ivanhoe Mines holds an indirect 90% interest in the Platreef Project and the Itochu-led Japanese consortium holds the remaining 10% interest that it acquired in two investments made in 2010 and 2011.

In accordance with South African law, Ivanhoe Mines has proposed transferring a 26% interest in the Platreef Project to BBBEE SPV, a broad-based, black economic empowerment partner. Ivanhoe is discussing the required finalization of the BBBEE structure with the government’s Department of Mineral Resources, with a goal of securing the granting of the Platreef Mining Right by the department by the end of May this year. The proposed BBBEE, in which Ivanhoe would retain a 49% interest, would represent the interests of employees, as well as communities.

Upon receipt of the Mining Right, Ivanhoe will own 64% of the Platreef Project, BBBEE SPV will own 26% and the Japanese consortium will own 10%.

Mineral Resources characterized by large thicknesses

The Flatreef Mineral Resource, with a strike length of 6.5 kilometres, predominantly lies within a flat to gently-dipping portion of the Platreef mineralized belt that occurs at relatively shallow depths of approximately 700 to 1,100 metres below surface.

The Flatreef Deposit is characterized by its very large vertical thicknesses of high-grade mineralization and a platinum-to-palladium ratio of approximately 1:1, which is significantly higher than other recent PGM discoveries on the Bushveld’s Northern Limb. The 2.0 g/t 2PE+Au grade shells used to constrain mineralization in the Indicated Resource area within the Flatreef have average true thicknesses of approximately 24 metres, while the Indicated Mineral Resource grade at the equivalent 2.0 g/t 3PE+Au cut-off is 4.1 g/t platinum-palladium-gold-rhodium (3PE+Au), 0.34% nickel and 0.17% copper. Flatreef’s Indicated Mineral Resources of 214 million tonnes contain an estimated 28.5 million ounces of platinum, palladium, gold and rhodium, 1.6 billion pounds of nickel and 0.8 billion pounds of copper. At the same cut-off of 2.0 g/t 3PE+Au, the current Flatreef estimate also includes Inferred Mineral Resources of 415 million tonnes grading 3.5 g/t 3PE+Au, 0.33% nickel and 0.16% copper, containing an estimated additional 47.2 million ounces of platinum, palladium, gold and rhodium, 3.0 billion pounds of nickel and 1.5 billion pounds of copper. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

Indications of significant additional mineralization in adjacent exploration targets

As updated in Ivanhoe Mines’ recent news release issued on March 19, 2014, mineralization at the Platreef Project is open to expansion to the south and west, beyond the currently established Mineral Resources (see Figure 4). Two exploration targets have been identified.

Target 1, the Ga-Madiba extension zone, is based on results from 14 wide-spaced, step-out drill holes completed between October 26, 2012, and February 18, 2014. Ga-Madiba, which adjoins and stretches to the south from the area where Inferred Mineral Resources are estimated, could contain 115 to 235 million tonnes grading 3.1 to 4.5 g/t 3PE+Au (comprising 1.2 to 1.7 g/t platinum, 1.7 to 2.3 g/t palladium, 0.06 to 0.14 g/t rhodium, 0.17 to 0.26 g/t gold), 0.23% to 0.28% nickel and 0.11% to 0.14% copper over an area of 3.7 square kilometres. The tonnage and grade ranges are based on intersections of 2.0 g/t 3PE+Au mineralization in drill holes completed in Target 1.

Drilling to date has successfully identified the T1 and T2 mineralized reefs and confirmed the initial interpretation that the Ga-Madiba target represents the southern strike extension to the shallow-lying Flatreef. The overall drill results are encouraging and the depth, range of grade, thickness and grade-thickness are comparable to the initial, 400-metre-spaced drill results in Flatreef’s zone 1 (prior to completion of the 100-metre x 100-metre infill drill program).

Target 2, which surrounds the currently estimated mineral resources in zones 1 and 2, could contain an estimated 260 to 450 million tonnes grading 3.4 to 4.5 g/t 3PE+Au (comprising 1.7 to 2.4 g/t platinum, 1.2 to 1.6 g/t palladium, 0.14 to 0.20 g/t rhodium, 0.26 to 0.33 g/t gold), 0.30% to 0.35% nickel and 0.15% to 0.18% copper over an area of 7.6 square kilometres. The tonnage and grade ranges are based on 2.0 g/t 3PE+Au intersections of mineralization in 19 wide-spaced drill holes completed in Target 2 and adjacent drill holes within the Inferred Mineral Resource area. These drill holes were completed between October 26, 2012, and February 18, 2014.

The potential quantity and grade of these exploration targets is conceptual in nature. There has been insufficient exploration and/or study to define these exploration targets as a Mineral Resource. It is uncertain if additional exploration will result in these exploration targets being delineated as a Mineral Resource. The potential quantity and grade of these exploration targets has not been used in the PEA.

In addition, there are approximately 37 square kilometres of unexplored ground beyond these two exploration target areas on the property under which the Platreef mineralization is projected to lie. It is not possible to estimate a range of tonnages and grades for this ground with current information. There is excellent potential for mineralization to significantly increase with further step-out drilling to the south-west.

Proposed mining methods

Stantec Consulting prepared an evaluation of three different production-rate scenarios (4 Mtpa, 8 Mtpa and 12 Mtpa) to mine the Indicated and Inferred Mineral Resources at the Platreef Project. The mining methods considered are long-hole stoping and drift-and-fill extraction, followed by either cemented paste, cemented rock fill or waste rock backfill, where applicable.

The mine plans have been developed for a total project life of 36 years, including a six-year pre-production period prior to the mill start-up.

Metallurgical test work and concentrator design

There have been a number of metallurgical test-work campaigns and conceptual flow-sheet designs carried out for the treatment of Platreef samples since 2001. Metallurgical test work focused on maximizing the recovery of platinum-group elements (PGEs) and base metals, mainly nickel, while producing an acceptably high-grade concentrate suitable for further processing and/or sale to a third party.

Previous comminution tests indicated that the plant feed is competent with respect to SAG milling and that a crusher and ball-mill circuit will be the preferred option. The Platreef material is classified as hard to very hard. The flotation test work has shown that the plant feed is amenable to treatment by conventional flotation without the need for re-grinding. Flotation losses from the circuit are due to a non-floating PGM population locked in gangue at sizes of 10 micrometre or finer.

Although this phase of the test work is preliminary, it did indicate that an effective flow sheet would involve several stages of cleaner flotation with recycling of the stage tailings. All of the three geo-met units and the two blends produced acceptable smelter-grade final concentrates at acceptable recoveries.

Based on the latest flotation test work results, a concentrator flow sheet was developed for the treatment of T1, T2 Upper and T2 Lower zones.

Phase 1 would include the construction of a 4 Mtpa concentrator and other associated infrastructure by 2020, in two modules of 2 Mtpa. Phase 2 would include a ramp-up to 8 Mtpa by 2024 and Phase 3 a further ramp-up to a plant capacity of 12 Mtpa by 2028.

A two-phased production approach was used for the Phase 1 flow-sheet development and design. The selected flow sheet is comprised of a common three-stage crushing circuit, feeding crushed material to two milling-flotation modules each of 2 Mtpa capacity. Milling is achieved in a ball mill with classification and rougher flotation in a split high-, medium- and low-grade circuit. Each concentrate is cleaned in a dedicated cleaner circuit with varying stages and recycles. Flotation is followed by tailings handling and concentrate thickening, filtration and storage.

Supply of electricity and water

The Olifants River Water Resource Development Project (ORWRDP) is designed to deliver water to the Eastern and Northern limbs of South Africa’s Bushveld Igneous Complex. The project consists of the new De Hoop Dam, the raising of the wall of the Flag Boshielo Dam and related pipeline infrastructure that ultimately will deliver water to Pruissen, southeast of Mokopane and the Platreef Project. The Pruissen Pipeline Project will be developed to deliver water on from Pruissen to the communities and mining projects on the Northern Limb. Ivanhoe is a member of the Joint Water Forum, which is part of the ORWRDP.

Participants in the water development scheme are required to indicate their water requirements so that total water demand may be calculated relative to the scheme’s capacity. These requirements are translated into a non-binding Memorandum of Agreement and then a binding, off-take agreement. The Platreef Project’s water requirement for the 8 Mtpa base case scenario would be approximately 22 million litres per day.

Eskom, the national power authority, has advised that sufficient power presently is not available in the Mokopane area due to transmission-line limitations and generating shortfalls. The generating shortfall should be alleviated with the first unit of the new Medupi Power Station that is due to begin operation in Q4 2014.

When fully operational, the Medupi Power Station will have the capacity to generate a total of up to 4,800 megawatts for the national grid.

The Medupi output, combined with the new Borutho main transmission substation, which is approximately 26 kilometres from the Platreef Project site and is due to begin operation this year, should ensure that sufficient power will be available for the Platreef Project.