Ore Resources and Mineral Resources
Set out below is a summary of the Sierra Rutile Group’s Ore Reserve and Mineral Resource estimates as at 31 December 2022.
Ore Reserve statement as at 31 December 2022 (JORC 2012)
Notes:
- The Ore Reserve estimate for the Sembehun Project remains unchanged due to no mining having taken place at Sembehun and no additional information has been included that may materially affect the Ore Reserve estimation of the Sembehun Project.
- For the year ending 2022, the Area 1 Ore Reserves increased by 2.5 Mt from 38.2 Mt to 40.7 Mt which is attributed to:
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- Depletion of active mining areas (- 10.4 Mt);
- Re-modelling and updating of the Gangama, Gbeni and Lanti Mineral Resource models;
- Updated pit designs;
- Application of updated exclusion zones;
- The combined effect of items b through e resulted in an increase of 3.8 Mt in the Ore Reserve estimate;
- Updated economic pit limit analysis input parameters;
- Economic pit limit analysis methodology;
- The inclusion of the Pejebu (+ 5.7 Mt) and Ndendemoia (+ 3.5 Mt) Mineral Deposits in the 2022 Ore Reserve estimate; and
- Application of modifying factors including:
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-
- Geological losses accounted for by utilising an optimised geological bed;
- Mining losses of 3%;
- Minimum mining area of 2,500 m²,
Mineral Resource statement as at 31 December 2022 (JORC 2012)
Notes:
- A calculated cut-off grade of 0.3% Rutile was applied to the new 2022 Mineral Resource estimates for Gangama, Gbeni and Lanti, while previously calculated variable grade cut-offs of between 0.25% and 0.5% Rutile have been applied to the balance of the project areas.
- Totals may not add up due to rounding.
- Models have been depleted for mining.
- Geological losses of 2.5%, 5.0% and 7.5% for Measured, Indicated and Inferred Mineral Resource Classification have been applied respectively to the calculated tonnages.
