Waterberg PGM Project, South Africa

Waterberg is a large-scale shallow natured platinum group metal (PGM) resource located on the Northern Limb of the Bushveld Complex in South Africa.

The project is owned by a joint venture (JV) of Platinum Group (37.05%), Impala Platinum Holdings (Implats) (15%), Japan Oil, Gas, and Metals National Corporation (JOGMEC) (12.195%), Hanwa (9.755%), and BEE partner Mnombo Wethu Consultants (26%).

Platinum Group, which also operates the PGM project, holds an effective interest of 50.02% in the Waterberg JV due to its 49.9% stake in Mnombo Wethu.

Waterberg was discovered in 2011. A Pre-Feasibility Study (PFS) of the project was completed in 2016. It was followed by the announcement of the Definitive Feasibility Study (DFS) results in September 2019.

According to the DFS, Waterberg will entail a capital of approximately ZAR13.1bn ($874m) along with ZAR3.5bn in capitalised operating costs to achieve 70% of steady state production.

The project secured a mining right from the South African Department of Mineral Resources and Energy in early 2021.

The mine will produce platinum (Pt), palladium (Pd), rhodium (Rh), and gold (Au), and is expected to have a life of around 45 years.

As of July 2023, Platinum Group Metals is working to advance the Waterberg Project to a development and construction decision, which includes arranging construction financing and signing concentrate offtake agreements.

Waterberg Project Location and Site details

The Waterberg PGM Project is located 85km north of Mokopane town in the South African province Limpopo at a height ranging between 880m and 1,365m above sea level.

The site is approximately 330km north-north-east (NNE) from Johannesburg. Overall, the project covers a total area of 99,244 hectares (ha).

Geology and Mineralisation

The Bushveld complex, which is one of the most well-known mafic/ultramafic layered intrusion globally, was intruded into rocks of the Transvaal Supergroup about 2,060 million years ago.

The Bushveld Complex hosts several layers rich in PGM, chromium (Cr), and vanadium (V).

The PGM mineralisation within the Bushveld Complex is hosted in two main layers- T Zone and F Zone.

Waterberg is situated on the northern end of the previously known Northern Limb of the Bushveld Complex. The mafic rocks in this part have a different sequence to those of the Eastern and Western Limbs of the Bushveld Complex.

Mineralisation in Waterberg is hosted by sulphides, with thick mineralised layers, which are often greater than 10m.

Waterberg Mineral Reserves

The Waterberg Project Mineral Reserve Estimate, effective September 2019, is based on the M&I Mineral Resource material contained in the T Zone and Super F Zone (F Zone) resource block models.

Waterberg’s aggregate measured and indicated mineral resource estimate at 2.5g/t 4E cutoff grading is 242.44 million tonnes containing 819,549kg of 4E metal at an average grade of 0.98g/t platinum (Pt), 2.13g/t palladium (Pd), 0.05g/t rhodium (Rh), 0.22g/t gold (Au), 0.10% copper (Cu), and 0.18% nickel (Ni).

The inferred mineral resources at 2.5g/t 4E cutoff grading stand at 66.7 million tonnes at an average grade of 3.27 g/t 4E, 0.11% Cu, and 0.15% Ni.

The total estimated proven and probable mineral reserves at 2.5g/t cutoff include 187.5 million tonnes at an average grade of 3.24g/t 4E, 0.09% Cu, and 0.18% Ni.

The project is expected to contain a total of 19.5 million ounces of platinum, palladium, rhodium and gold.

Mining and Ore Processing

The Waterberg project will involve a mechanised underground mining operation accessed via declines from surface.

The design of the mine is based on using the sublevel long hole stoping mining method to extract mineral resources contained in the T and F zones and then, backfilling the mined voids with paste backfill.

Long hole mining method is a highly mechanised, highly productive, and low-cost bulk method that is employed globally.

All decline and lateral excavations will be carried out by diesel-powered mobile equipment using drill and blast methods.

The waste rock will be trucked from the site to an identified dump point, while the recovered ore will be hauled by 50-tonne capacity trucks to rock breaker / grizzly stations for sizing and loading onto the conveyor system.

The process design for the concentrator plant was developed on the basis of metallurgical testwork and assessments.

The Run-Of-Mine (ROM) from the Central Complex portal will be transported to a primary crushing section and then crushed to less than 317mm.

The crushed material will be stored on an open stockpile before undergoing secondary and tertiary crushing.

The blended material from primary crushing circuit will be separated three size fractions by either one of two dual deck, coarse ore screens.

The screening and crushing circuit will convert the material into a -13mm product as feed to the mill feed silo of 13,000-tonne capacity.

The primary milling circuit will be equipped with a 14 MW, 7.21 m × 10.67 m EGL grate discharge ball mill operating in closed circuit with a classification screen.

Primary milled product will be pumped to a classification screen, the screen oversize product will be recycled back to the primary mill feed and the undersize product will gravitate to the primary rougher flotation circuit.

The primary milling classification screen undersize product will be transferred to the primary rougher flotation circuit to produce a single concentrate product.

Meanwhile, the primary rougher tailings and the primary cleaner tailings will be transferred to the mill discharge sump and then to the secondary mill classification cyclone and subsequent flotation.

In the head of the scavenger flotation bank, the collector, depressant, and frother will be introduced.

The primary rougher concentrate product will be combined with the primary recleaner tailing product after it is pumped into the primary cleaning circuit.

The high, medium, and low-grade concentrate products from flotation will be sent to the 33m diameter high-rate concentrate thickener.

The thickened concentrate will be sent to either of two concentrate filter feed surge tanks and then, it will be pumped to either of the two final concentrate filters. The concentrate will be dewatered to a product containing less than 12% moisture.

The final product will be stored on the floor from where it will be loaded into trucks for transportation to the smelters.

Waterberg Project Infrastructure

The Waterberg project infrastructure includes regional, local, and site-specific infrastructure. The site features basic infrastructure and supports agricultural activities.

An existing national road network can be used to access the boundary of the site.

Key infrastructure that will be built includes bulk water supply, 132kV electrical supply from the ESKOM Power Utility, access roads, and telecommunication and internet services.

Additionally, the project will include 132kV consumer substation, ESKOM switching yard, 11kV electric reticulation, ventilation fans (multiple), explosives magazine, explosive destruction area, potable water treatment plants, backfill plant, and sewerage treatment plant.

Contractors involved

The definitive feasibility study (DFS) of the Waterberg project was prepared by Stantec- Mining. Several other companies such as DRA Projects, CJM, Turnberry Projects, Bateleur

Environmental & Monitoring Services (BE), and Sustainable Slurry and Backfill Solutions (SSBS) were also associated.

Stantec Consulting International and DRA Projects were selected as the lead independent project engineers following a tender process.