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| Ore reserves increased in total |
| The Anglo Platinum Ore Reserves and Mineral Resources described are found predominantly in the Bushveld Complex where most of Anglo Platinum’s exploration is focused. In the pursuance of this exploration in 2007, one fatal accident regrettably occurred, although in other respects, prospecting operations were carried out with a high level of safety adherence. |
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In 2007, the Anglo Platinum Ore Reserves increased in total and importantly in the Proved category, while total Mineral Resources decreased by 6.7% compared to the previous year. Details of the movements in reserves and resources are supplied in full in the tabulations that follow and, as can be gathered from the indication
of the amount of ongoing exploration that the Company is conducting, movements will be a feature going forward in 2008.
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| In addition to the effects of exploration
(which overall tend to move the classification
of resources higher up the order), it is
anticipated that BEE transactions will be
concluded early in 2008 and these will then
be reflected in further changes to Mineral
Resources and Ore Reserves in reporting
the 2008 statistics. |
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| The Bushveld Complex |
According to the Johnson Matthey website section
'Platinum Supply and Demand in 2007', South Africa
produced 79% of the world's platinum, 34% of the
palladium and 87% of the rhodium. Although probably
coincidental, these production statistics closely reflect
the current view of South Africa's share of total world
resources of these metals. These resources reside
mostly in South Africa's uniquely large, mineral-endowed
layered igneous intrusion known as the Bushveld
Complex.
Formed just over 2,000 million years ago, when molten
rock known as magma was injected into the upper
reaches of the earth's crust from chambers deep below,
the Bushveld Complex is an enormous, irregularly
shaped saucer 350 kilometres across, with its central
area deep underground but its commercially valuable
rim exposed at or near surface on the western, eastern
and northern sides, or 'limbs'. At the outer edges of
each of the limbs, rocks known as pyroxenites, norites,
gabbros, and chromitites are found inter-layered in a
variety of combinations that make up several readily
identifiable zones that extend the length and breadth of
the complex. Within these zones are a number of
orebodies that yield a variety of minerals such as
chromite, titaniferous magnetite, vanadium pentoxide,
nickel, copper and, more importantly for Anglo Platinum,
the PGMs or platinum group metals.
Within the sequences of rocks, there are three distinct
layers that contain concentrations of PGMs at levels
that are currently economic to mine. Other layers in the
Bushveld sequences also carry PGMs, but none of these
can currently be extracted on the basis of PGM content
alone. The principal PGM-bearing horizons are the
Merensky Reef and the Upper Group 2 (UG2) Reef,
which occur around the Eastern and Western Limbs of
the complex, while a third PGM-rich layer, the Platreef,
is found only on the Northern Limb at the northeastern
edge. Although there are other deposits similar
to Platreef in some respects, such as Sheba's Ridge,
these have yet to be mined.
The Merensky Reef has been the principal source of
PGMs since it was first worked in 1925. However, the
other reefs have grown in importance, so that by 1999
the Merensky Reef accounted for just over 50% of all
platinum-bearing ore processed in South Africa.
Exploitation of the UG2 began in the 1970s and has
steadily increased; in 1999, it was the source of 42% of
ore processed and is now thought to exceed 50%
across the complex. The UG2 is found at a vertical
distance of between 16 and 400 metres below the
Merensky Reef, depending on location. The Platreef,
briefly mined in the 1920s, was first exploited on a large
scale in 1993 and is gradually becoming a significant
contributor of PGMs for Anglo Platinum.
Although narrow (the Merensky and UG2 Reefs are
generally mined at a stoping width of less than a metre),
these tabular orebodies extend laterally over hundreds
of square kilometres, resulting in extensive Mineral
Resources whose continuity, established over years of
exploration and mining, enables long-range extrapolation
of data.
On the Northern Limb of the Bushveld, the UG2 is not
developed on Anglo Platinum's properties. The Platreef
referred to above, which is found in place of the other
reefs and, in contrast to the Merensky and UG2 Reefs,
is substantially thicker and is well developed on Anglo
Platinum properties. The term Platreef describes zones
of mineralisation occurring in a variety of rocks that
range from normal pyroxenites through a host of rock
types that have arisen through contamination of
Bushveld magma by sediments from the underlying
Transvaal Supergroup. The thicknesses of Platreef are
such that they can support open-pit mining operations
to depths well in excess of 200 metres at current prices
and mining costs and, significantly, provide a much safer
mining environment than underground mining.
The Merensky and Platreef yield meaningful quantities
of nickel and copper as by-products of PGMs. The UG2
is relatively devoid of nickel and copper, and although
chromitite in the UG2 has potential for economic gain
and in some areas is being exploited in this way, this has not been considered in measuring the contained
monetary values for ore reserve purposes. Even though
other base metals in the UG2 are not significant, they
are recovered and the value obtained is accounted for
in the relevant economic evaluations. |
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| CHANGES IN THE ORE RESERVE AND MINERAL RESOURCE STATEMENT FOR 2007 |
| Ore Reserve – Mineral Resource summary |
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2007 |
2006 |
| Category |
Mt |
Moz |
Mt |
Moz |
| Total Ore Reserves |
1,453.3 |
194.1 |
1,399.0 |
192.4 |
| Proved Ore Reserves |
808.6 |
104.6 |
778.7 |
103.0 |
| Total Mineral Resources |
5,696.0 |
720.0 |
6,108.1 |
804.8 |
| Measured Mineral Resources |
621.8 |
91.1 |
567.6 |
82.0 |
| Measured and Indicated Mineral Resources |
2,188.6 |
280.8 |
2,241.4 |
291.0 |
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| The total Ore Reserves increased primarily from the conversion of additional Mineral Resources to Ore Reserves at: |
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Rustenburg Section (UG2 Reef); and |
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BRPM JV – Styldrift (Merensky Reef). |
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This resulted in a 3.9% tonnage increase and a 0.9% 4E ounce increase in total Ore Reserves. |
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| The Proved Ore Reserves increased primarily due to additional Ore Reserves tonnages from: |
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Rustenburg Section (UG2 Reef) where Mineral Resources were converted to Ore Reserves; and |
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Amandelbult Section (UG2 Reef) where additional drilling and re-evaluation resulted in higher confidence. |
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This resulted in a 3.8% tonnage increase and a 1.5% 4E ounce increase. |
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| The total Mineral Resource tonnage has decreased considerably, mainly due to: |
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the exclusion of certain Merensky and UG2 Reef Mineral Resources due to the refusal of prospecting rights by
the DME (see footnote); |
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the conversion of additional Mineral Resources to Ore Reserves at Rustenburg Section (UG2 Reef), BRPM JV –
Styldrift (Merensky Reef) and Modikwa Platinum Mine JV (UG2 Reef); and |
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Booysendal JV project (Merensky Reef) where additional drilling and re-evaluation resulted in a decrease of the
Mineral Resources tonnages. |
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However, Mineral Resource tonnages increased in the following areas: |
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Ga-Phasha PGM project and Der Brochen project (both Merensky Reef) where additional drilling and re-evaluation
resulted in increased resource cuts. |
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This resulted in a 6.7% tonnage decrease and a 10.5% 4E ounce decrease. |
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| The overall increase in Measured Mineral Resources stems mainly from higher confidence due to additional drilling and
re-evaluation at: |
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Rustenburg Section (UG2 Reef), Lebowa Platinum Mines (Merensky and UG2 Reef), PPRust (Platreef), Amandelbult
Section (UG2 Reef), Der Brochen Project (Merensky Reef) and Union Section (UG2 Reef). |
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However, these increases are offset by the decrease in tonnage mainly due to: |
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Der Brochen project (UG2 Reef), where additional drilling and re-evaluation resulted in a confidence decrease;
and |
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BRPM JV – Styldrift where Mineral Resources were converted to Ore Reserves. |
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This resulted in a 9.6% tonnage increase and an 11.1% 4E ounce increase. |
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| The decrease in Measured and Indicated Mineral Resources stems mainly from the conversion of Mineral Resource to
Ore Reserves at: |
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Rustenburg Section (UG2 Reef); |
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BRPM JV – Styldrift (Merensky Reef); |
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Modikwa Platinum Mine JV (UG2 Reef); and |
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Der Brochen project (UG2 Reef) where additional drilling and re-evaluation resulted in a confidence decrease. |
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However, these decreases are offset by the increase in tonnage mainly due to: |
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higher confidence based on additional drilling and re-evaluation at Der Brochen project (Merensky Reef), PPRust
(Platreef), Lebowa Platinum Mine (UG2 Reef) and Amandelbult Section (UG2 Reef); and |
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Union Section where economic assumptions previously reported Ore Reserves are restated as Mineral
Resources. |
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This resulted in a 2.4% tonnage decrease and a 3.5% 4E ounce decrease. |
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For details go to statistics. |
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