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mineral reserves & mineral resources

The Mineral Resources and Mineral Reserves of the Implats group are cornerstones of the wealth of the company. The group is accordingly committed to the following strategies:

  • growth of the mineral resource base by optimising the current assets, exploration and acquisitions; including alliances and equity interests with third parties;
  • full commitment to the legislative regime that governs mineral right ownership;
  • transparent disclosure of Mineral Resources and Mineral Reserves aligned with the prescribed codes, SAMREC and JORC; and
  • continuous improvement in mineral resource management systems.

The mining operations of Implats and its associated companies exploit platiniferous horizons within the two largest known deposits of platinum group metals (PGMs) in the world, namely the Great Dyke in Zimbabwe and the Bushveld Complex in South Africa. Mining mostly takes place as underground operations focusing on relatively narrow mineralised channels with the specific methods adapted to suit the local geology and morphology of the mineralised horizon. Underground stoping in the Great Dyke currently consists of mechanised or semi-mechanised bord-and-pillar layouts. Within the Bushveld Complex, mechanised mining is being utilised at Two Rivers and only in limited areas at the Impala Platinum mining operations. The mining method at Marula Platinum is being converted from mechanised layouts to conventional breast mining. The bulk of the mining at Impala Platinum is conventional breast mining with limited opencast mining taking place at the outcrop position. Opencast mining at Zimplats continues although this will be reduced over the next few years.

Great Dyke and Bushveld Complex

THE GREAT DYKE

The Great Dyke is a 2.5 billion-year old layered mafic-ultramafic complex that transects the Zimbabwean Archaean Craton in a NNE-trending direction. The Dyke is highly elongate, slightly sinuous, 550 kilometres long, with a maximum width of 12 kilometres. The Dyke is divided into two major successions, a lower ultramafic sequence dominated from the base upwards by cyclic repetitions of dunite, harzburgite and bronzitite, and an upper mafic sequence consisting mainly of gabbro and gabbronorite. Much of the mafic sequence has been removed by erosion. The ultramafic sequence hosts the P1 pyroxenite, directly below the mafic-ultramafic contact, which in turn hosts the economic PGM-bearing Main Sulphide Zone (MSZ). The MSZ is a lithologically continuous layer between 2 and 10 metres thick that forms an elongated basin. Layers of igneous rocks within the basin dip at between 5 degrees and 20 degrees near the margins and flatten out near the centre to form a flat-lying floor. The MSZ typically contains iron-nickel-copper sulphides whilst elevated precious metal concentrations occur towards the base of the MSZ. Optimal mineralisation varies and is often difficult to follow visually, in contrast to the Bushveld Complex. Peak values for the PGM and base metals are commonly offset, while the proportions between platinum and palladium also vary vertically. The Dyke developed as a series of initially discrete magma chamber compartments, which joined up as the chambers filled. The chambers coalesced below the MSZ and before erosion, the MSZ would have been continuous along the length of the Dyke. In its present plane of erosion, the Great Dyke is longitudinally subdivided into a series of narrow contiguous layered complexes or chambers, namely Musengezi, Hartley, Selukwe and Wedza. The Hartley Complex straddles two sub-chambers, Darwendale and Sebakwe.

As at 30 June 2005, Implats held 86.9% of Zimbabwe Platinum Mines Limited (Zimplats), an Australian-listed company. Zimplats operates the Ngezi Platinum mine situated in the south of the Hartley Complex, and mines both by opencast and underground methods. Zimplats owns extensive Mineral Resources within the Hartley Complex. In addition, Implats owns 50% of Mimosa Investments Limited, which owns and operates Mimosa Mining Company, an underground mine situated in the Wedza Complex.

THE BUSHVELD COMPLEX

The Bushveld Complex is an extremely large, 2-billion-year old layered igneous intrusion occurring within the boundaries of South Africa. Although it shares many characteristics with other layered complexes around the world, the Bushveld Complex is unique both in its size, covering an aerial extent of some 66,000 square kilometres, and in the economic importance of its mineral deposits. It is generally understood that the Bushveld Complex was formed by the repeated injection of magma into a sub-volcanic chamber. Due to the huge volumes of magma involved, cooling and crystallization were slow processes. Different minerals were formed as the magma cooled; these accumulated into sub-horizontal layers building from the base of the chamber. Such processes were repeated by the intermittent replenishment of magma thus producing a repetition of the mineral layering.

The complex comprises an array of diverse igneous rocks ranging in composition from ultramafic to felsic. Contained within a well-layered ultramafic to mafic succession, called the Rustenburg Layered Suite, are two horizons which host economically exploitable quantities of PGMs, namely the Merensky Reef and the underlying UG2 Chromitite Layer. These two economic horizons can be traced for hundreds of kilometres around the complex and are the focus of Implats' operations in which the PGMs platinum, palladium, rhodium, ruthenium and iridium are recovered together with quantities of gold, nickel, copper and cobalt. Implats' operations here comprise Impala Platinum Limited, located near Rustenburg in North West Province, and Marula Platinum situated near Burgersfort in the province of Limpopo. The Two Rivers mine, a joint venture between Implats and African Rainbow Minerals (ARM), is located south of Burgersfort in the province of Mpumalanga.

The Merensky Reef is generally composed of a feldspathic pyroxenite hangingwall, overlying a basal chromitite unit, followed by an anorthosite to anorthositic-norite footwall. The Merensky Reef Zone at Impala Platinum's mining operations displays a gradational mineralised zone, with grades decreasing from the Merensky chromitite unit into the footwall and hangingwall. The UG2 Reef is defined as a main chrome unit with the mineralisation wholly contained within this unit.


Regulatory compliance

The reporting of Mineral Resources and Mineral Reserves for Implats' South African operations is done in accordance with the principles and guidelines of the South African Code for Reporting of Mineral Resources and Mineral Reserves (SAMREC Code). (See Glossary of terms).

Zimplats, as an Australian Stock Exchange listed company, reports its Ore Reserves and Mineral Resources in accordance with the Australasian Code for Reporting of Mineral Resources and Ore Reserves (JORC Code). Mimosa Investments Limited, a Mauritius-based company, does not fall under any regulatory reporting code but has adopted the JORC Code for its reporting. Various Competent Persons, as defined by the SAMREC and JORC codes, have prepared the Mineral Reserve and Mineral Resource figures quoted in this report. They were reviewed and signed off by the Implats' signatory below:

JJ Vermaak
Pr.Sci.Nat. (Consulting Geologist, Impala Platinum) The Competent Person has 19 years' experience in the evaluation and exploitation of PGM deposits.

Additional compliance:
  • the Competent Person for the Two Rivers' Mineral Resources and Reserves is Mr PJ van der Merwe, full-time employee of ARM;
  • the Competent Persons for Zimplats are Messrs A du Toit, J Wheeler and S Simango, full-time employees of Zimplats;
  • Aquarius Platinum South Africa (Pty) Ltd (AQP(SA)) uses a number of Competent Persons. Implats has not verified the AQP(SA) Mineral Resource and Mineral Reserve estimates in detail, as AQP(SA) is not a subsidiary of Implats;
  • Implats has obtained written consent from ARMPlatinum and AQP(SA) that the information disclosed pertaining to their Mineral Resources and Mineral Reserves is compliant with the SAMREC Code and can be published in this form;
  • Implats is committed to external reviews of all Mineral Resource and Mineral Reserve estimates, at least once in a three-year cycle, as well as to additional audits as the need may arise. During the past year, SRK Consulting reviewed the Mineral Resources and Ore Reserves for Zimplats, the UG2 Mineral Resource at Marula and the UG2 Mineral Resources and Mineral Reserves for Two Rivers. Snowden Mining Consultants reviewed the Mineral Resource estimates for the 16 and 20 Shaft Blocks at Impala;
  • Implats has legal entitlement to the mining of minerals being reported upon without any known impediments; and
  • reporting of the Mineral Resources and Mineral Reserves for Impala and Marula is quoted both inclusively and exclusively. This is for more direct comparisons with companies that subscribe to the inclusive form of reporting as well as to provide a basis of comparison with 2004. Inclusive reporting implies that Mineral Reserves are included in Mineral Resources, whereas exclusive reporting means that Mineral Reserves are not included in Mineral Resources.

Salient highlights

Material and significant issues affecting the Mineral Resource and Mineral Reserve estimates as at 30 June 2005 relative to the previous reporting period are:

  • the completion of the 16 and 20 Shaft Project studies at Impala Platinum and their subsequent approval resulted in a movement from the Mineral Resource category to that of Probable Mineral Reserve;
  • the revision of the Marula Platinum mine plan necessitated a restatement of the Mineral Resources and Mineral Reserves;
  • the approval of the Two Rivers Project resulted in the UG2 Mineral Resource being upgraded to Mineral Reserve status;
  • the Zimplats Mineral Resource and Ore Reserve estimates were revisited in view of additional work and changes to the JORC Code;
  • the sale of Implats' 27% interest in Lonmin affected overall attributable Mineral Resources and Mineral Reserves; and
  • as at 30 June 2005, the implementation of a new integrated Mineral Resource Management (MRM) system at Impala's mining operations was nearing completion. The initial objective is to focus on the optimisation of the Mineral Resources and Mineral Reserves of the current operations.


IMPALA PLATINUM


Impala Platinum mining operations

MINERAL RESOURCES AND MINERAL RESERVES: Impala Platinum holds contiguous old order mining and prospecting rights for a total area of 27,573 hectares. The Mineral Resources and Mineral Reserves quoted are held under four old order mining rights, two old order prospecting rights as well as an unused old order right. Impala Platinum applied for the conversion of these rights during FY2005.

Efforts are being made to increase the Mineral Resource base in adjacent areas in conjunction with BEE partnerships.

Mineral Resources (exclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
Merensky Measured 34.4 7.47 4.7 60.7 7.46 8.3
Indicated 84.7 7.48 11.7 101.5 7.66 14.3
Inferred 75.4 7.83 10.9 75.9 8.26 11.5
UG2 Measured 14.4 8.79 1.9 49.5 8.90 6.7
Indicated 96.2 9.13 13.4 70.2 9.45 10.1
  Inferred 62.9 9.25 8.9 62.1 9.28 8.8
Total 368.0 8.34 51.5 419.9 8.42 59.7

Mineral Reserves as at 30 June 2005 as at 30 June 2004
Mill Grade (g/t) Mill Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
Merensky Proved 24.3 4.88 2.2 17.1 5.12 1.6
Probable 110.8 4.81 9.8 72.7 4.97 6.6
UG2 Proved 21.2 5.13 1.7 20.5 5.15 1.6
  Probable 110.1 5.09 8.5 99.9 5.11 7.8
Total   266.4 4.96 22.2 210.2 5.07 17.7

Mineral Resources (exclusive) as at 30 June 2005 as at 30 June 2004
Tonnes Pt grade Pt oz Tonnes Pt grade Pt oz
Orebody Category (millions) (g/t) (millions) (millions) (g/t) (millions)
1&2 Tailings
complex Indicated 48.1 0.42 0.6 48.1 0.42 0.6

Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
Merensky Measured 137.1 6.99 17.6 126.2 7.23 16.8
Indicated 84.7 7.48 11.7 101.5 7.66 14.3
Inferred 75.4 7.83 10.9 75.9 8.26 11.5
UG2 Measured 96.9 9.05 13.4 103.2 9.11 14.3
Indicated 96.2 9.13 13.4 90.8 9.43 13.1
  Inferred 62.9 9.25 8.9 62.1 9.28 8.8
Total 553.2 8.17 75.9 559.7 8.38 78.8

Notes

  • Mineral Resources are stated in both the exclusive and inclusive form to facilitate comparisons with companies reporting solely inclusive Mineral Resources. A direct comparison of tonnes and grade is not possible between the two forms due to the mixing of channel and mill figures.
  • The modifying factors used to convert a Mineral Resource to a Mineral Reserve are derived from historical figures using an in-house ore accounting system. This system is able to provide dilution factors that are applied to the in situ estimates to yield the final product delivered to the mill.
  • The Mineral Reserves quoted reflect the grade delivered to the mill rather than an in situ channel grade quoted in respect of Mineral Resources.
  • The decrease in the mill grades is, in part, a result of the reduction in planned improvements in dilution control over the first two years of the life-of-mine plan until existing planned improvements are met, and in part due to an increase in mechanization, which has resulted in an increase in mining widths. In addition, lower Merensky Reef channel grade estimates also impact on projected mill grades.
  • Material changes in the Mineral Resource and Mineral Reserve categories arise from Board approval of the 16 and 20 shaft projects. This resulted in the upgrading and transferal of the Mineral Resource to the Mineral Reserve category. Certain UG2 project areas were reviewed and subsequently downscaled to the resource category.
  • An alternative approach in the evaluation of pillars and white areas has led to a reduction of these areas in the resource categories.
  • The Impala 30-year mine plan comprises approximately 48% Mineral Reserves and 52% Mineral Resources. Some 11% of the 30-year mine plan is derived from the Inferred Mineral Resources. It should also be noted that 6% of the 30-year mine plan is derived from prospecting areas, with close to 11% of the life-of-mine being derived from prospecting areas.

Impala Platinum – Merensky metals split
Impala Platinum – Merensky metals split


Impala Platinum – UG2 metals split
Impala Platinum – UG2 metals split

Impala Platinum – Merensky Reef
Impala Platinum – UG2 Reef

MARULA PLATINUM

MINERAL RESOURCES AND MINERAL RESERVES: Marula Platinum holds old order mining rights on the farms Winnaarshoek 250KT, Clapham 118KT, and portions of the farms Driekop 253KT and Forest Hill 117KT, comprising 2,765 hectares. The Mineral Resources and Mineral Reserves quoted are held under two old order mining licences. Marula Platinum applied for the conversion of the two old order mining licences during FY2005. As at 30 June 2005, the new order prospecting right for the Hackney area was still awaited.

Mineral Resources (exclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
Merensky Indicated 44.2 5.47 4.2 44.2 5.47 4.2
Inferred 5.2 5.73 0.5 5.2 5.73 0.5
UG2 Indicated 22.0 9.80 2.6 22.4 9.27 2.5
  Inferred 3.5 8.88 0.4 3.5 8.88 0.4
Total 74.9 6.92 7.7 75.3 6.78 7.6

Mineral Reserves as at 30 June 2005 as at 30 June 2004
Mill Grade (g/t) Mill Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
UG2 Probable 41.9 5.16 2.6 41.3 4.76 2.3

Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 5 PGE Pt oz tonnes 5 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
Merensky Indicated 44.2 5.47 4.2 44.2 5.47 4.2
Inferred 5.2 5.73 0.5 5.2 5.7 0.5
UG2 Measured 29.7 9.90 3.6 25.7 9.53 2.9
Indicated 22.0 9.80 2.6 22.4 9.27 2.5
  Inferred 3.5 8.88 0.4 3.5 8.88 0.4
Total 104.6 7.77 11.3 101.0 7.58 10.5

Notes

  • Mineral Reserves quoted reflect the grade delivered to the mill rather than an in situ channel grade quoted in respect of the Mineral Resources.
  • The modifying factors used in the UG2 mineral reserve calculation are based on the revised mine plan which envisages hybrid and conventional breast mining operations.
  • The UG2 Mineral Resource merely accounts for the UG2 chromitite layer while the Merensky Reef Mineral Resource is based on a minimum width of 80 centimetres;
  • Significant changes since previous UG2 Mineral Resource estimates relate to additional information, re-assaying of some existing boreholes and also updated estimation practices.
  • An external third party audit was completed by SRK by September 2004 on the UG2 Mineral Resources of Marula. The SRK audit concluded that Impala Platinum complies with general reporting standards.

Marula Platinum – Merensky metals split
Marula Platinum – Merensky metals split


Marula Platinum – UG2 metals split
Marula Platinum – UG2 metals split

Marula Platinum – Merensky Reef
Marula Platinum – UG2 Reef


ZIMPLATS

Impala Platinum mining operations

MINERAL RESOURCES AND ORE RESERVES: During 2005, the company was restructured so that all of Zimplats Mineral Resources are 100%-owned by Zimplats through its wholly-owned subsidiaries. Previously, the open pit and Hartley Mineral Resources were 30%-owned by Implats. Implats shareholding has increased to 86.9% of Zimplats as at 30 June 2005. No finality has been reached regarding the potential participation of indigenisation parties. The figures quoted below refer to the total Mineral Resource and Ore Reserve (in terms of JORC).

Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
MSZ Measured 95.7 3.69 5.6 102.9 4.19 6.8
Indicated 719.0 3.76 43.0 860.6 4.13 55.7
  Inferred 1,690.1 3.41 92.2 1,528.0 4.11 98.6
Total 2,504.8 3.52 140.8 2,491.5 4.12 161.1

Ore Reserves as at 30 June 2005 as at 30 June 2004
Mill Grade (g/t) Mill Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
MSZ Proved 51.5 3.28 2.7 45.1 3.23 2.3
  Probable 215.1 3.32 11.4 295.7 3.35 15.6
Total 266.6 3.31 14.1 340.8 3.34 17.9

Notes

  • Mineral Resources are quoted inclusive of Ore Reserves.
  • The Ore Reserves quoted reflect anticipated grades delivered to mill.
  • Mineral Resources were estimated using moving averages and kriging techniques on data derived from surface drill holes. Estimates are based on composite widths that vary depending on cut-off grades, which are based on appropriate economic conditions.
  • Since the last declaration of Mineral Resources and Ore Reserves, detailed drilling has continued in the Ngezi area and reconnaissance drilling was completed to the north of Hartley. Zimplats has also remodelled the entire Mineral Resource base. The result is that the underlying geological model has changed.
  • Previously a fixed width of 1.2 metres and a grade of 2g/t platinum had been assigned to the Inferred Mineral Resource. In the current model, the width and grade were estimated, based on the data available. This has increased the width and reduced the grade.
  • More realistic geological losses were applied, based on a re-evaluation of the data and on recent mining experience. Previously a blanket 3% loss was applied while currently factors range from 2% to 20% depending on the geological conditions.
  • During the past year, a new release of the JORC Code was issued and Zimplats has prepared a code of practice based on this revision. Zimplats decided that the Code would be more closely honoured if losses due to inevitable pillars underground and inherent dilution caused by the extent of micro faulting and minor intrusions were allowed for in the Mineral Resource declaration.
  • The company has gained considerable experience mining underground at Portal 2 and this was compiled into a full feasibility study. In order to comply with the change in the JORC Code that requires a mine plan for all Ore Reserves, SRK Consulting in Johannesburg has prepared appropriate mine plans and financial models in support of a pre-feasibility for the Ngezi area.
  • The reduction in Ore Reserves was due to:
    • a change to the maximum dip for bord-and-pillar mining from 12 degrees previously to 9 degrees, based on experience within the Implats group;
    • refinements in underground mine design which highlighted the need for Inferred Mineral Resources to be progressed to generate additional Ore Reserves. These Inferred Mineral Resources lie adjacent to the deepest part of the previous Ore Reserve area;
    • reduced extraction rates, especially in the deeper parts of the Ore Reserve; and
    • drilling and subsequent refinement of the ultimate open pit design which resulted in reduced tonnage. Some of these open pit Ore Reserves may be mined from underground in future, given the significant cost differential between the two mining methods.
  • In addition to the pre-feasibility study, SRK Consulting conducted an external review of platinum mineral resource and ore reserve estimation and reporting practices in September 2004. This was updated on 4 July 2005. SRK concluded that Mineral Resource estimates are valid and that within the limitations of the data, the results appear meaningful. Further details regarding Zimplats' Mineral Resource and Ore Reserve estimates can be sourced from the 2005 Zimplats Annual Report.

Zimplats – MSZ – metals split
Zimplats – MSZ – metals split


MIMOSA

MINERAL RESOURCES AND ORE RESERVES: The lease encompasses four areas, North Hill, South Hill, Mtshingwe Block and Far South Hill, separated by major faults, covering an area of 6,590 hectares. As at 30 June 2005, Implats owned a 50% shareholding in Mimosa Investments Limited (with Aquarius Platinum Limited owning the remaining 50%).

Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
South Hill Measured 39.4 4.18 2.7 31.8 4.07 2.1
(1.8m cut) Indicated 27.2 3.93 1.7 31.7 3.81 1.9
Inferred 13.5 4.06 0.9 18.2 3.95 1.2
  Inferred (oxides) 6.0 3.91 0.4 7.2 3.81 0.4
Total 86.1 4.06 5.7 88.9 3.93 5.6

Ore Reserves as at 30 June 2005 as at 30 June 2004
Mill Grade (g/t) Mill Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Orebody Category (millions) & Au (millions) (millions) & Au (millions)
South Hill Proved 16.1 3.76 1.0 16.1 3.75 1.0
(1.8m cut) Probable 16.2 3.54 0.9 13.7 3.51 0.8
Total 32.3 3.65 1.9 29.8 3.64 1.8

Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Channel
tonnes Grade (g/t) Pt oz tonnes Grade (g/t) Pt oz
Orebody Category (millions) 2 PGE* (millions) (millions) 2 PGE* (millions)
North Hill Inferred 40.0 3.16 2.5 40.0 2.96 2.2
(1.8m cut) *(2E grade – Pt and Pd only)

Notes

  • The figures quoted refer to the total Mineral Resource and Ore Reserve for North and South Hill.
  • Compared with previously published figures, the material differences are:
    • a correction to the lease boundary position on the western perimeter, which resulted in a loss of 0.78 million tonnes from the Indicated Mineral Resource and 0.17 million tonnes from the Inferred Mineral Resource;
    • the Inferred Oxide Mineral Resource decreased following a re-interpretation of the areas containing the Mineral Resource;
    • an increase in the PGE grade due to a downwards shift of the economic channel of 15 centimetres, since the economic channel is based on the optimisation of the PGE metal content;
    • updated low-grade zones following in-fill drilling to determine the lateral extent of these features; and
    • decreased grades due to an increase in the losses from in situ to blasted to mill feed Ore Reserve grades (this offsets the increase in the Mineral Resource grade).
  • Oxide material is quoted separately as on-going metallurgical test work is being conducted to verify the economic viability of these resources.
  • Ore Reserves are quoted as fully diluted delivered to mill;
  • Mineral Resources are quoted inclusive of Ore Reserves.
  • The Mineral Resources have taken into account the following extraction losses:
    • Measured Resource: 3% for dykes and faults, 3% for adverse ground conditions, 5% for washouts and abnormal reef;
    • Indicated Mineral Resource: 3% for dykes and faults, 3% for adverse ground conditions, 8% for washouts and abnormal reef; and
    • Inferred Mineral Resource: 3% for dykes and faults, between 3% and 13% for adverse ground conditions, 8% for washouts and abnormal reef.
  • In situ grade was used for the calculation of Mineral Resources.
  • Known anomalous zones and washout channels were excluded from the Mineral Resource.
  • Trial mining is currently ongoing at wider widths in order to optimise extraction from the Mineral Resource base. This has indicated a potential increase at a 1.95 metres cut in the South Hill Resources of 7.18 million tonnes and 0.21 million ounces of platinum and the North Hill Resources of 3.3 million tonnes and 0.15 million ounces of platinum.

Mimosa South Hill – metals split
Mimosa South Hill – metals split
Mimosa South Hill Deposit MSZ

TWO RIVERS

MINERAL RESOURCES AND MINERAL RESERVES: Implats has a 45% shareholding in Two Rivers (with ARMPlatinum owning the remaining 55%).

Mineral Resources (inclusive) as at 30 June 2005  
Channel tonnes Grade (g/t) Pt oz
Orebody Category (millions) 3 PGE & Au (millions)
Merensky Indicated 18.7 3.34 1.2
Inferred 3.9 3.16 0.2
UG2 Measured 13.1 5.17 1.2
  Indicated 46.2 3.70 2.9
Total 81.9 3.83 5.5

Mineral Reserves as at 30 June 2005  
Mill tonnes Grade (g/t) Pt oz
Orebody Category (millions) 3 PGE & Au (millions)
UG2 Proved 10.5 3.59 0.7
  Probable 29.8 3.44 1.7
Total 40.3 3.48 2.4

Notes

  • A second external audit was completed by SRK Consulting (SA) by March 2005 on the UG2 Mineral Resource and Mineral Reserve figures.
  • Mineral Resources are quoted inclusive of Mineral Reserves.
  • The figures quoted below refer to the total Mineral Reserve and Mineral Resource for Two Rivers Platinum Limited as at 30 June 2005.
  • The modifying factors used in the UG2 Mineral Reserve calculations are based on mechanised room and pillar mining operations. Estimated geological losses, rock engineering pillars and rock engineering losses due to geological features were accounted for in the Mineral Resource calculations.
  • Grade estimates were obtained by means of ordinary kriging of UG2 and Merensky Reef borehole intersections.
  • The Mineral Reserves quoted above include the North Open Pit and tonnes mined during the trial mining that were stock piled.
  • More details regarding the Mineral Resources and Mineral Reserves can be obtained in the 2005 ARM Annual Report.
Two Rivers Platinum – Merensky Reef
Two Rivers Platinum – UG2 Reef

Two Rivers – UG2 metals split
Two Rivers – UG2 metals split

AQUARIUS PLATINUM

MINERAL RESOURCES AND ORE RESERVES: as at 30 June 2005, Implats held a 20% equity interest in Aquarius Platinum SA (AQP(SA)). This percentage interest is divorced from contractual toll smelting agreements. Implats also owns a 8% interest in Aquarius Platinum Limited.

Summary tabulation of AQP(SA) Mineral Resource and Ore Reserves:
Mineral Resources (inclusive) as at 30 June 2005 as at 30 June 2004
Channel Grade (g/t) Channel Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Category (millions) & Au (millions) (millions) & Au (millions)
Measured 60.1 4.46 5.1 64.9 4.49 5.6
Indicated 29.5 3.91 2.2 31.7 3.97 2.4
Inferred 8.0 3.37 0.5 8.5 3.45 0.6
Total 97.6 4.21 7.8 105.1 4.25 8.6
Inferred (exploration prospects) 542.0 5.04 52.2 534.6 5.08 52.6

Ore Reserves as at 30 June 2005 as at 30 June 2004
Mill Grade (g/t) Mill Grade (g/t)
tonnes 3 PGE Pt oz tonnes 3 PGE Pt oz
Category (millions) & Au (millions) (millions) & Au (millions)
Proved 57.1 3.09 3.4 61.4 3.12 3.7
Probable 18.1 3.16 1.1 18.9 3.28 1.2
Total 75.2 3.11 4.5 80.3 3.16 4.8

Notes

  • Mineral Resources are reported inclusive of Ore Reserves.
  • The figures reflect the total Mineral Resources and Ore Reserves.
  • Details for the above figures can be obtained from Aquarius Platinum Limited's 2005 Annual Report.

IMPLATS ATTRIBUTABLE OUNCES

The table below summarizes the total attributable platinum ounces contained in all categories of Mineral Resources for all the Implats' group companies and strategic interests. This does not account for potential future BEE participation.

Implats' consolidated platinum ounces – Resource and Reserves (million ounces) as at 30 June 2005
Impala Platinum*74.3
Marula Platinum*10.3
Zimplats122.3
Mimosa Platinum4.1
Aquarius Platinum1.6
Two Rivers2.5
Total215.1
* Based on resource and reserve ounces (exclusive reporting). All others based on inclusive reporting.
 
Impala Platinum Holdings Limited
Annual Report 2005