Mineral Reserves and Mineral Resources

• Introduction
  • Salient highlights 2007
  • Geological settings
  • The Bushveld Complex
  • The Great Dyke
  • Regulatory compliance
  • Mineral rights status
  • Auditing on 2007
  • Pertinent assessment & reporting criteria
  • Key year-on-year changes in reporting
  • Reconciliation
• Impala
• Marula
• Afplats
• Two Rivers
• Zimplats
• Mimosa
• Aquarius Platinum
• Mineral Resource summary

Impala

The Impala mining operation is located just to the north of Rustenburg on the western limb of the Bushveld Complex. The complex comprises an array of diverse igneous rocks, ranging in composition from ultramafic to felsic. Contained within this well-layered ultramafic to mafic succession are two horizons in the Critical Zone which host economically exploitable quantities of PGMs, namely the Merensky Reef and the underlying UG2 Reef. Both reefs sub-outcrop in the lease area and dip generally in a north-east direction at about 10°. The vertical separation between the Merensky and UG2 Reefs varies from about 125m in the south to some 45m in the north.

The Merensky Reef is generally composed of an upper feldspathic pyroxenite, overlying a thin basal chromitite stringer, followed by an anorthosite to norite footwall and with the mineralisation decreasing from the basal chromitite stringer into the hangingwall and footwall. The UG2 Reef is defined as a main chromitite layer, with most of the mineralisation contained within this unit, followed by a poorly mineralised pegmatoidal pyroxenite footwall.

Impala holds contiguous old order mining and new order prospecting rights for a total area of 33,188ha across 20 farms or portions thereof. The prospecting area involving the joint venture with Royal Bafokeng Resources has not been factored into the Mineral Resource estimate; this will be facilitated once sufficient studies have been completed.

Both the Merensky and UG2 Reefs are being exploited; the bulk of the mining at Impala Platinum is conventional breast mining. Mechanised bord and pillar mining takes place in selected areas only, while limited opencast mining takes place at the outcrop position.

Impala – Mineral Resources

		as at 30 June 2007				as at 30 June 2006
Orebody	Category	Channel tonnes (millions)	Grade (g/t) 3PGE+Au	Grade (g/t) 5PGE+Au	Pt oz (millions)	Channel tonnes (millions)	Grade (g/t) 3PGE+Au	Grade (g/t) 5PGE+Au	Pt oz (millions)
Merensky	Measured	121.3	6.06	6.94	15.4	131.4	6.00	6.88	16.5
	Indicated	89.3	6.13	7.02	11.5	76.4	6.44	7.38	10.3
	Inferred	71.2	6.83	7.83	10.2	76.3	6.83	7.83	10.9
UG2	Measured	117.8	6.93	9.03	16.3	105.1	6.88	8.96	14.5
	Indicated	73.8	6.75	8.79	9.9	98.8	6.85	8.92	13.5
	Inferred	58.5	6.96	9.06	8.1	60.8	7.09	9.24	8.6
Total		531.9	6.56	8.03	71.4	548.8	6.62	8.11	74.3

Impala – Mineral Resources (tailings)

		as at 30 June 2007				as at 30 June 2006
Orebody	Category	Tonnes (millions)	Pt grade (g/t)	Pt oz (millions)		Tonnes (millions)	Pt grade (g/t)	Pt oz (millions)
1 & 2 Tailings Complex	Indicated	48.1	0.42	0.6		48.1	0.42	0.6

Impala – Mineral Reserves

		as at 30 June 2007				as at 30 June 2006
Orebody	Category	Mill tonnes (millions)	Grade (g/t) 3PGE+Au	Grade (g/t) 5PGE+Au	Pt oz (millions)	Mill tonnes (millions)	Grade (g/t) 3PGE+Au	Grade (g/t) 5PGE+Au	Pt oz (millions)
Merensky	Proved	23.0	4.07	4.66	2.0	24.6	4.15	4.76	2.1
	Probable	104.7	4.04	4.63	8.9	109.9	4.12	4.72	9.5
UG2	Proved	23.2	3.89	5.06	1.8	23.9	3.89	5.07	1.9
	Probable	105.6	3.88	5.06	8.2	105.5	3.85	5.02	8.2
Total		256.4	3.96	4.85	20.8	264.0	3.99	4.88	21.6

Notes:

• Mineral Resources are quoted inclusive of Mineral Reserves.
• Mineral Resource estimates allow for estimated geological losses and anticipated pillar losses during eventual mining.
• 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 project 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 Inferred Mineral Resource estimate has been reduced by some 7Mt, primarily due to the exclusion of an area in the northern extremity of the current mining right area. The exclusion is based on the lack of potential future prospects of mining in line with depth and the shape of the relevant portion.
• Other changes influencing the movement between categories include primarily
  (a) the reclassification of some of the previously reported Measured Mineral Resources at 17 shaft to the Indicated category;
  (b) the exclusion of 4.7Mt from the 20 shaft UG2 Mineral Reserve base in light of revised shaft design limits; and
  (c) upgrading of part of the UG2 Mineral Resource to the Mineral Reserve category.
• Mineral Resource and Mineral Reserve grades are now also reflected in a 3PGE+Au format as opposed to the 5PGE+Au format reported previously. The estimated contained ounces are based on the 5PGE+Au grades and metal proportions.
• Rounding–off of numbers may result in minor computational discrepancies.