Petra Diamonds Limited
Annual Report and Accounts 2013
110
8. Impairment of operational assets and investments
continued
8.2 Impairment tests – other mining operations 30 June 2013 and 30 June 2012
a) Non-impaired operations
The Group performs impairment testing on an annual basis of all operations and when there are potential indicators which may
require impairment. In addition to Sedibeng JV and Star, the Group also performed impairment testing for Cullinan, Finsch, Helam,
Koffiefontein, Kimberley Underground and Williamson. The results of the impairment testing performed did not indicate any
impairments on the remaining mining operations. As set out in the Group’s accounting policies, only reserves and resources
and capital expenditure plans included within the Group’s life of mine plans are used. The key assumptions used in determining
the recoverable value calculations, determined on a value in use basis, are listed in the table below:
Key assumptions
Explanation
Recoverable value of
reserves and resources
Economically recoverable reserves and resources are based on management’s expectations based on the
availability of reserves and resources at mine sites and technical studies undertaken in-house and by third
party specialists. Resources remaining after the current life of mine plans have not been included
in impairment testing for the above operations.
Life of mine – reserves
and resources
Cullinan
– Life of mine includes C-cut Phase 1 and reprocessing of certain tailings over the next 17 years
(30 June 2012: 18 years); total resource processed 101 Mt (57.6 Mt underground ROM and 43.4 Mt tailings)
(30 June 2012: 115.0 Mt (65.3 Mt underground ROM and 49.7 Mt tailings)) at a rate of 5.5 Mtpa (2.8 Mtpa
underground ROM tonnes and 2.7 Mtpa tailings tonnes) (30 June 2012: 5.7 Mtpa (3.0 Mtpa underground ROM
tonnes and 2.7 Mtpa tailings tonnes)) increasing to 6.7 Mtpa (4.0 Mtpa underground ROM tonnes and 2.7 Mtpa
tailings tonnes) (30 June 2012: 8.0 Mtpa (4.0 Mtpa underground ROM tonnes and 4.0 Mtpa tailings tonnes)).
Finsch
– Life of mine includes Block 5 over the next 17 years (30 June 2012: 18 years); total resource
processed 74.5 Mt (53.0 Mt underground ROM and 21.5 Mt tailings) (30 June 2012: 87.1 Mt (61.3 Mt
underground ROM and 25.8 Mt tailings)) at a rate of 5.5 Mtpa (2.8 Mtpa underground ROM tonnes and
2.7 Mtpa tailings tonnes) (30 June 2012: 5.6 Mtpa (2.8 Mtpa underground ROM tonnes and 2.8 Mtpa
tailings tonnes) increasing to 6.2 Mtpa (3.2 Mtpa underground ROM tonnes and 3.0 Mtpa tailings tonnes))
(30 June 2012: 7.0 Mtpa (3.5 Mtpa underground ROM tonnes and 3.5 Mtpa tailings tonnes)).
Helam
– 17 years (30 June 2012: 18 years) life of mine plan; total resource processed 1.9 Mt (30 June 2012: 2.0 Mt)
at a rate of 0.1 Mtpa (30 June 2012: 0.1 Mtpa).
Koffiefontein
– 12 years (30 June 2012: 13 years) life of mine plan; total resource processed 14.2 Mt
(12.0 Mt underground ROM and 2.2 Mt surface/tailings tonnes) (30 June 2012: 22.3 Mt (13.3 Mt underground
ROM tonnes and 9.0 Mt surface/tailings tonnes)) at a rate of 1.5 Mtpa (0.3 underground ROM tonnes and
1.2 Mtpa surface/tailings tonnes) (30 June 2012: 1.7 Mtpa (0.3 Mtpa underground and 1.4 Mtpa surface/
tailings tonnes) reducing to 1.1 Mtpa (1.1 Mtpa underground and 0.0 Mtpa surface/tailings tonnes)).
Kimberley Underground
– 13 years (30 June 2012: 10 years) life of mine plan; total resource processed 12.8 Mt
(30 June 2012: 9.8 Mt) at a rate of 1.1 Mtpa increasing to 1.25 Mtpa (30 June 2012: 1.0 Mtpa).
Williamson
– 20 years (30 June 2012: 18 years) life of mine plan: total resource processed 95.5 Mt (30 June 2012:
64.0 Mt) at a rate of 3.9 Mtpa increasing to 5.0 Mtpa (30 June 2012: 3.0 Mtpa increasing to 3.6 Mtpa).
Life of mine – capital
expenditure
Management has estimated the timing and quantum of the capital expenditure based on the Group’s
current life of mine plans for each operation. There is no inclusion of capital expenditure to enhance
the asset beyond exploitation of the life of mine plan orebody.
Diamond prices
Diamond prices are based on guidance prices as shown on page 19. The ROM US$/carat price range
used in the calculations was US$140–US$650 (30 June 2012: US$140–US$600).
Notes to the Annual Financial Statements
For the year ended 30 June 2013 continued
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