20974 29Metals AR23 WEB V1 - Flipbook - Page 80
29Metals 2023 Annual Report
76
Mineral Resources & Ore Reserves Estimates continued
Changes in Ore Reserve Estimates
Changes to Ore Reserves es琀椀mates for Capricorn Copper, rela琀椀ve to the last es琀椀mates (31 December 2022) are outlined below.
Material changes comprise:
■
■
■
■
Deple琀椀on – 0.5Mt, re昀氀ec琀椀ng the actual mining and processing ac琀椀vi琀椀es in the 12-months to 31 December 2023;
Mineral Resources es琀椀mates – increases in Mineral Resources es琀椀mates for ESS (refer above);
Economic cut-o昀昀 assump琀椀ons – changes to cut-o昀昀 grades for all deposits, re昀氀ec琀椀ng changes in key economic assump琀椀ons, including:
– increase in copper price to US$3.63/lb from US$3.60/lb;
– reduc琀椀on in foreign exchange rate to US$0.69/AUD from US$0.73/AUD;
– increased forecast mining cost for ESS, Mammoth Deeps and Remnants, Esperanza Deeps and Pluto and lower mining costs for
Greenstone;
– increased combined forecast costs for processing and site services;
– minor reduc琀椀on in selling costs from changes in the copper price, exchange rate, freight cost, percentage royalty and payable
percentage; and
– revisions to dilu琀椀on assump琀椀ons for cuto昀昀 calcula琀椀on; and
Mine design:
– the addi琀椀on of the Mammoth North deposit
– changes to stope designs for Mammoth Deeps, Mammoth Remnants, Greenstone, Esperanza Deeps and Pluto based on depleted
and revised Mineral Resource es琀椀mates and revised cut-o昀昀s; and
– update to the SLC design for ESS based on revised Mineral Resources es琀椀mates, revised cut-o昀昀 and shuto昀昀 grades, and
incorpora琀椀ng transverse SLC as the predominant method below 4675 level rather than longitudinal SLC.
Economic cut-off assumptions
The following economic cut-o昀昀 assump琀椀ons were applied for the purposes of the 31 December 2023 Ore Reserves es琀椀mates for
Capricorn Copper. Cut-o昀昀 for the prior es琀椀mates (31 December 2022) are also provided for the purposes of comparison.
For the purposes of Ore Reserves es琀椀mates, an ini琀椀al set of cut-o昀昀 grades were applied to create stope shapes. These cut-o昀昀 grades
are shown under “Stope op琀椀misa琀椀on cut-o昀昀” in the table below. A 昀椀nal, revised set of cut-o昀昀 grades, shown under “Final Head Grade
(Diluted)” in the table below was subsequently applied to exclude any stopes for which the overall stope grade was lower than or equal
to the 昀椀nal cut-o昀昀.
Cut-o昀昀 assump琀椀ons
31-Dec-23
Orebody
Esperanza South Total
31-Dec-22
Stope
Op琀椀misa琀椀on
Cut-o昀昀
Final Head
Grade %Cu
(Diluted)
Stope
Op琀椀misa琀椀on
Cut-o昀昀
Head
Grade %Cu
(Diluted)
N/A
1.27
1.17
1.17
Esperanza South Shuto昀昀
N/A
0.96
0.99
0.99
Esperanza South Development
N/A
0.81
0.87
0.83
Greenstone
1.08
0.96
1.11
1.06
Greenstone Development
0.65
0.60
0.64
0.60
Mammoth (Remnants and Deeps)
1.29
1.36
1.44
1.36
Mammoth North
1.03
1.28
N/A
N/A
Mammoth Development
0.65
0.60
0.64
0.60
Pluto
1.62
1.55
1.74
1.59
Pluto Development
0.72
0.66
0.71
0.67
Esperanza
1.81
1.64
1.71
1.55
Esperanza Development
0.71
0.65
0.70
0.66
Commodity Price and Foreign Exchange
Pricing/FX
Copper
AUD:USD
Unit
31-Dec-23
31-Dec-22
US$/lb
3.63
3.60
0.69
0.73
