South Africa

Amandelbult Complex

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Overview

Mine TypeUnderground
Commodities
  • PGM
  • Platinum
  • Palladium
  • Rhodium
  • Iridium
  • Ruthenium
  • Gold
  • Nickel
  • Copper
  • Chrome
Mining Method
  • Breast stoping with strike pillars
  • ULP / XLP
Shaft Depth 1,300 m
Production Start1976
Mine Life2048
ShapshotAmandelbult mine is a part of the world’s largest open pit PGMs mine.

Amandelbult complex comprises Tumela and Dishaba mines, and two operational concentrators with two chrome plants. The current working mine infrastructure has five vertical and seven decline shaft systems to transport rock, men and material, mining on the Merensky and UG2 Reef horizons.

The Amandelbult Mine Complex(AMB) intends to commence with several mining capital projects across its operations in the AMB mining right area and surface right area. In the absence of significant alternative employment opportunities in the area, the proposed capital projects will allow the AMB to continue with the mining activities for the Life of Mine (LoM), which is beyond 2060.
Related AssetsDishaba Mine, Tumela Mine

Owners

SourceSource
CompanyInterestOwnership
Anglo American plc. 76.99 % Indirect
Rustenburg Platinum Mines Ltd. (operator) 100 % Direct
Ownership Tree
Anglo American plc. through its subsidiary Rustenburg Platinum Mines owns 76.99% of the Amandelbult complex.

Contractors

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Deposit type

  • Magmatic

Summary:

The mines Tumela and Dishaba are forms part of the Amandelbult section and fully developed situated on the north-western limb of the Bushveld Complex.The mining occurs on both the Merensky Reef and the UG2 Reef horizons.

THE BUSHVELD COMPLEX
Formed over 2 billion years ago from multiple injections of magma into the earth’s crust many kilometres below the surface, the Bushveld Complex is geologically unique due to its size, uniformity of its layering and extent of known mineral content. This saucer-shaped intrusion is over 350km wide, 250km long and up to 12km thick. Over time, the rim of the intrusion has been exposed by erosion, revealing three separate main segments known as the Western, Eastern and Northern Limbs. The Western Limb is split into two lobes (north-western and south- western) by the Pilanesberg complex, a remnant of an alkaline volcanic plug intruded into the Bushveld Complex about 1,250 million years ago. The Eastern Limb is split into two lobes (north-eastern and south-eastern) by the north- east trending Steelpoort fault. The exposed segments exhibit layering of pyroxenites, norites, gabbros, anorthosites and chromitites and this layering occurs across the entire extent of the complex. Within the layers, mineralisation is found in specific horizons containing chromium, iron, titanium, vanadium, nickel, copper and PGM.

The Bushveld Complex comprises three main suites, namely the Rooiberg Group, Lebowa Granite Suite and Rustenburg Layered Suite. The Rustenburg Layered Suite comprises four major subdivisions: the Upper Zone, Main Zone, Critical Zone and Lower Zone. Economic concentrations of PGMs occur mainly in three distinct units within the Critical Zone: Merensky Reef; Upper Group 2 (UG2) chromitite; and Platreef. The Merensky Reef and UG2 Reef occur around the Eastern and Western Limbs of the complex, while the Platreef is found only along the eastern edge of the Northern Limb.

The Merensky and UG2 reefs are narrow tabular orebodies that extend laterally over hundreds of square kilometres, resulting in extensive Mineral Resources.

The Merensky Reef
The Merensky Reef has been the principal source of PGM since it was first mined in 1925. The reef contains economically important PGM and base metal sulphide Mineralisation. However, with the depletion of shallow Merensky Resources, the UG2 Reef, which is found at a minimum vertical distance of 12m to 400m below the Merensky Reef, depending on location, has grown steadily in importance to the point where it now accounts for most of the platinum- bearing ore processed in South Africa.

The Merensky Reef is extensively well developed in both the Eastern (EL) and Western Limbs (WL) of the Bushveld Complex. The reef is well defined and typically consists of a pegmatoidal feldspathic pyroxenite layer, bounded on the top and bottom by thin chromitite layers (stringers) that have thicknesses ranging from 5mm to 20mm. Mineralisation of the reef generally occurs in the pegmatoidal feldspathic pyroxenite and, to a limited extent, in the hanging wall and footwall, with highest PGM concentration peaking at the chromitite stringers.

In the WL, the Merensky Reef dips in an arc ranging from 18º to 27º south-easterly direction in the Amandelbult area and at 9º to 12º northerly direction in the Rustenburg area. It has a variable reef thickness ranging from 1cm (Contact Reef facies) to >2m, over large areas. At Amandelbult complex in particular, the reef comprises up to five different facies. Each facies type exhibits unique geomorphological, geochemical and mineralisation characteristics and plays a fundamental role in geozone delineations and Resource and Reserves widths. In the EL, the Merensky Reef is slightly thicker and dips at 8º to 18º in a south-westerly direction.

The UG2 Reef
The UG2 Reef, which is consistently developed throughout the EL and WL, is rich in chromitite, but with lower gold and base metal content compared to Merensky Reef. In the WL, the UG2 Reef occurs between 12m and 150m vertically below the Merensky Reef and dips at 18º to 27º in a south-easterly direction (Amandelbult area). In the EL, the reef occurs between 120m and 400m vertically below the Merensky Reef and dips at 8º to 18º in a south- westerly direction.

In the WL, the UG2 normally comprises a 0.6m to 1.0m main chromitite band overlain by three chromitite bands (UG2 leaders) varying in thickness from 5cm to 30cm, separated by feldspathic pyroxenite. The immediate footwall of the UG2 is usually a pegmatoidal feldspathic pyroxenite, which varies in thickness from a few centimetres to over 1m. The separation distances between these UG2 leader chromitite bands and the UG2 main band has important implications for geotechnical considerations for mining.

In the EL, the UG2 normally comprises a main chromitite band varying in thickness from 0.3m to 1.0m, overlain by three or up to four chromitite stringers varying in thickness from 2mm to 1cm. The immediate footwall of the UG2 is usually a pegmatoidal feldspathic pyroxenite, which varies in thickness from a few centimetres to over 1m. The separation distances between these UG2 hanging wall stringers has important implications for geotechnical considerations for mining.

In the EL south of the Steelpoort fault, UG2 chromitite is an amalgamation of UG2 main chromitite with the leader chromitite unit, the two usually indistinguishable but may be separated based on their Pt/Pd ratios varying in thickness from 0.60m to 2.25m (averaging 1.20m). This is overlain by a poikilitic feldspathic pyroxenite parting varying in thickness from millimetres to 15m and averaging 1m. This parting is overlain by three chromitite bands (up to 20cm), separated by poikilitic feldspathic pyroxenite and pegmatoidal pyroxenites commonly referred to as the ‘triplets’ with an average thickness of 80cm.

Reserves

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Mining Methods

  • Breast stoping with strike pillars
  • ULP / XLP

Summary:

The complex has two mines (Tumela and Dishaba) and three concentrators with a chrome plant. Current working infrastructure has five vertical and seven decline shaft systems to transport rock, employees and material, with mining on the Merensky and UG2 reef horizons. The operating depth for current workings runs from surface to 1.3km below surface.

The primary mining method used at Amandelbult complex is scattered breast mining for both Dishaba and Tumela mines.

Conventional scattered breast mining is preceded by haulage development below reef, parallel to strike. Access to the reef horizon is developed by means of south or north crosscuts. On-reef true dip raises or winzes connect to cross-cuts on different levels by means of step overs and travelling ways. The ore passes are generally done by inverse drilling (from the reef horizon down to the crosscut). Modernised equipment is being rolled out on the stoping horizon to address safety and efficiency concerns, including the introduction of cycle mining, split panels utilising throw blasting and water-jet cleaning to eliminate the use of scraper winches.

Extra-low profile (XLP) mechanised mining method is being implemented at the 15E dropdown project area since inception in 2019. The XLP mechanised mining is an underground mining method designed to exploit narrow reef orebodies (1.2m to 1.7m width) with a dip less than 22°. It maximises reef extraction by placing the primary development (main infrastructure) on reef. A constant production is achieved by coordinating XLP and low profile (LP) equipment to continuously feed the conveyor belt system.

The Tumela Mine is situated in the province of Limpopo in South Africa, between the towns of Northam and Thabazimbi, within the North-western Limb of the Bushveld Complex. The mine operates under a mining right covering a total area of 110 km2.

The current working mine infrastructure consists of three vertical and four decline shaft systems to transport rock, men and material. The mining occurs on both the Merensky Reef and the UG2 Reef horizons, and the mine is subdivided into two production areas, namely the Tumela lower mine and the Tumela upper mine. The predominant mining layout is conventional scattered breast mining with strike pillars. The operating depth for the current workings is between 180 metres and 895 metres below surface.

Dishaba Mine is situated in the province of Limpopo in South Africa, between the towns of Northam and Thabazimbi, and forms part of the North-western Limb of the Bushveld Complex. The mine operates under a mining right covering a total area of 31 km2.

The mine’s infrastructure consists of one vertical shaft, one raise bore and four decline shafts. Dishaba mines on both the Merensky Reef and the UG2 Reef horizons, and the mining layout is scattered breast mining with strike pillars. The operating depth for the current workings is between 30 metres and 1,250 metres below surface.

Underground mining occurs via two complexes, namely Tumela Mine (western section of the mine) and Dishaba Mine (north eastern section of the mine)
• The conventional breast mining method is widely used with mechanised mining recently introduced at Tumela 15E
• The ore is scraped into stope ore passes and then hauled (footwall haulages) by battery powered locomotives to the main hoisting shafts
• From surface the ore is transported to the concentrator by rail
• Conventional mining is currently being undertake at the Amandelbult Mine Complex

The Amandelbult Mine Complex currently employs a labour-intensive conventional mining methodology for the mining of its narrow tabular ore body. In 2021 Anglo American Platinum commenced with the implementation of a portfolio of mechanised mining projects as volume replacements for the depleting conventional / modernised investment centres. The development of the mechanised mining knowledge base will be leveraging technical and operational learnings from the Tumela 15E Mechanised project together with industry best practice. The mechanisation initiative was included in the latest business plans, with associated allocation of the relevant budgets to each project.

The mechanisation projects consist of the following four major Capital Projects and associated infrastructure:
• Middellaagte Upper & Middellaagte Lower;
• Tumela 1 Sub Shaft;
• Tumela 15E Extension; and
• Dishaba East Upper and Dishaba East Lower.

Comminution

Crushers and Mills

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Processing

  • Desliming
  • Spiral concentrator / separator
  • Gravity separation
  • Crush & Screen plant
  • Electric furnace
  • Flotation
  • Dewatering

Summary:

Amandelbult complex facility comprises three concentrators with a chrome plant.

The concentrator complex is capable of processing 600 ktpm. The ore undergoes several processes, including milling and concentrating, to extract the target minerals. The concentrate is transported to off-site smelters for further refinement.

Ore mined from the reserves is processed at the AMB Concentrator before being transported to various AAP smelters for smelting and further refining at the Rustenburg Base Metals Refinery and Precious Metals Refinery. The main metal produced is platinum with other metals in the platinum group metal (PGM) suite that being chrome, rhodium, palladium, ruthenium, iridium, osmium, and including gold. Base metals produced, include copper, nickel and cobalt.

Concentrator complex
Mined ore from the shafts at RPM – Amandelbult section are hoisted to the surface and trammed separately to the two rail receiving bunkers, from where the ore is stored at the Concentrator. The refined ore is then transported by rail to the Waterval Smelter in Rustenburg for processing and further refining.

The smelter objective is to process wet concentrate to produce crushed, slowcooled, sulphur-deficient nickel-copper matte rich in platinum group metals, gold, and base metals for despatch to the Magnetic Concentration Plant at the Base Metals Refinery.

Wet concentrate is dried, then melted in electric furnaces, and excess iron sulphides are removed in the ACP converter. A slag cleaning furnace treats gangue from the converter, while a slag milling and flotation circuit treats the slag from the electric furnaces.

Wet concentrate with an average moisture content of 16-17% by mass is delivered by road in flexi-side tippers or containers, and offloaded in the concentrate-receiving shed. Slurries with a solids content of 50-60% are pumped or delivered by tanker to the Waterval Complex Concentrate Handling plant (WCCH) for dewatering.

In the flash drying process, moisture is removed from the wet concentrate, producing a dry furnace feedstock (<0.5% H2O). The energy for the process is provided by burning coal in a fluidised bed (silica sand) combustor known as a hot gas generator (HGG).

The two electric furnaces are of Hatch design, with a rated transformer capacity of 39 MVA (34 MW maximum or 30 MW nominal design), and a design operating factor of 90%. The rectangular furnaces have internal dimensions of 8.0 x 25.8 m, and the calculated power flux at nominal design is 146 kW/m². The shell is constructed from refractory bricks held together by a precision-designed tension system.

Waterval furnace matte (WFM) is tapped into matte ladles and transported by crane to one of two granulation stations. The ladle is placed on a hydraulically driven tilter that pours the matte into a granulation launder at a predetermined rate. The launder discharges above a stream of granulating water that shearquenches the matte, forming fine particles suitable for dry feeding into the ACP converter.

The slag-cleaning furnace (SCF) is a 12 m diameter round furnace, designed by Pyromet, rated at 30 MVA (23 MW). Three Söderberg electrodes, each 1 400 mm in diameter, deliver power into the bath at currents up to 80 kA. The high currents are required due to the high conductivity of the slag. The resulting high slag temperatures led to the design choice of water-cooled copper sidewalls in the form of Pyromet Maxicoolers. This maximises energy removal, and eliminates the need for annual refractory repairs.

The flotation circuit consists of two 30 m³ cascading Outokumpu tank cells, followed by 14 flotation cells, currently functioning as a single rougher bank. Concentrate is pulled from each of the two tank cells and every flotation cell, then sent to the flue dust thickener. Tailings from the flotation cells are pumped to a tailings dam.

Chrome recovery plant
The plant has two modules, each employing a multi-stage configuration of separators and spirals. It produces two final chromite concentrates, one a metallurgical grade concentrate and the other a chemical grade. The chrome content of the concentrates is approximately 42 %. The two concentrates are pumped to their respective stockpile areas via their own dewatering separators. At the stockpile facility, the chromite is loaded onto trucks (for delivery to domestic customers) or rail wagons (for delivery to international customers via Richards Bay).

The chrome-silica cyclone underflow from the two UG2 plants serves as the dedicated feed stream to the chrome recovery plant and is pumped to two agitated feed surge tanks. From the surge tanks the slurry is delivered to desliming/separator cyclones located prior to the spirals circuit. The cyclone underflow then reports to the spirals circuit by gravity feeding. The spiral nests have been arranged to ensure optimum and equal feed distribution between all individual spirals starts. Where possible, the various stages of rougher, cleaner and recleaner spirals are stacked vertically above one another to maximise gravity feed arrangements to each section.

Production

CommodityProductUnits2023202220212020201920182017
PGM Metal in concentrate koz 000000000000000868858
Platinum Metal in concentrate koz 000000000000000443438
Palladium Metal in concentrate koz 000000000000000205202
Rhodium Metal in concentrate koz 00000000007775
Iridium Metal in concentrate koz 00000000002827
Ruthenium Metal in concentrate koz 000000000000111110
Gold Metal in concentrate koz 0000000005.25.5
Nickel Metal in concentrate kt 0000000001.31.4
Copper Metal in concentrate M lbs 00000000001.21.4
Chrome Concentrate kt 000000000000000832654

Operational metrics

Metrics202320222021202020192018
Tonnes milled 4,385 kt5,268 kt5,925 kt4,516 kt7,057 kt6,961 kt
Ore tonnes mined 5,268 kt5,925 kt4,516 kt7,057 kt6,961 kt

Production Costs

Commodity202320222021202020192018
Cash costs PGM 0000 0000 0000 0000 873 / oz  USD 864 / oz  USD
Cash costs Platinum 1,719 / oz  USD 1,695 / oz  USD
Total cash costs Platinum 1,725 / oz  USD 1,717 / oz  USD
All-in sustaining costs (sold) 3E (Pt, Pd, Au) 00000000 00000000 00000000 00000000 985 / oz  USD
All-in sustaining costs (sold) PGM 00000000 00000000 00000000
All-in sustaining costs (sold) Platinum 390 / oz  USD 794 / oz  USD
Net of By-Product.

Operating Costs

Currency20232022202120202019201820172016
Total operating costs ($/t milled) ZAR 2,929  2,278  1,986  2,109  1,510  1,300  1,197  1,092  

Financials

Units2023202220212020201920182017
Sustaining costs M ZAR 1,478  1,191  1,063  741   998   811   563  
Capital expenditures M ZAR 1,792  1,736  1,555  1,184   1,172   980   456  
Revenue M ZAR 23,866  32,889  41,662  18,248   17,424   13,192   11,423  
EBIT M ZAR 5,094  16,070  23,237  7,060   4,311   1,269   450  
EBITDA M ZAR 5,962  16,962  24,151  7,809   5,132   2,031   1,173  
Operating Cash Flow M ZAR 16,134  24,766  

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Source Source
Job TitleNameProfileRef. Date
Acting General Manager Charl Engelbrecht LinkedIn Mar 11, 2024
Health, Safety & Environment Manager Alwyn Smit LinkedIn Mar 11, 2024
Production Manager Solly Khumalo LinkedIn Mar 11, 2024
Sr. Engineering Manager Willem van Loggerenberg LinkedIn Mar 11, 2024

EmployeesContractorsTotal WorkforceYear
12,342 905 13,247 2023
12,326 1,093 13,419 2022
13,559 924 14,483 2021
13,980 1,627 15,607 2020
14,232 1,431 15,663 2019
14,490 1,300 15,790 2018
14,108 1,714 15,822 2017
13,879 1,147 15,026 2016

Aerial view:

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