• Operations

Reserves and Resources

Mineral Resources

The 2021 Mineral Resource update, effective December 25, 2020, incorporates production since the 2019 Mineral Resource was completed. The 2021 mineral resources for the Karowe Mine have been classified as either indicated or inferred Mineral Resources, according to CIM Guidelines. Mineral Resources reported are inclusive of those portions of the Mineral Resources that have been converted to Mineral Reserves.

Karowe Mine AK06 Updated Mineral Resource Statement

 

Classification

Resource

Tonnes
(Mt)

Carats
(Mcts)

Grade
(cpht)

Indicated

 

 

South M/PK(S)

25.51

2.74

10.7

South EM/PK(S)

20.84

4.43

21.2

Centre

2.78

0.42

15.2

North

0.82

0.09

10.6

TOTAL INDICATED

49.96

7.67

15.4

 

Inferred

 

South M/PK(S)

0.31

0.03

10.5

South EM/PK(S)

4.18

0.87

20.9

South_KIMB3

0.94

0.10

10.9

TOTAL INFERRED

5.43

1.01

18.6

Notes:

  • Prepared by Cliff Reverling, P.Eng. of SRK Consulting
  • Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. All numbers have been rounded to reflect accuracy of the estimate. Base of Indicated is 250masl, base of Inferred is 66masl.
  • Mineral Resources are in-situ Mineral Resources and are inclusive of in-situ Mineral Reserves.
  • Mineral Resources are exclusive of all mine stockpile material.
  • Mineral Resources are quoted above a +1.25 mm bottom cut-off and have been factored to account for diamond losses within the smaller sieve classes expected within the current configuration of the Karowe Mine process plant.
  • Inferred Mineral Resources are estimated on the basis of limited geological evidence and sampling, sufficient to imply but not verify geological grade and continuity. They have a lower level of confidence than that applied to an Indicated Mineral Resource and cannot be directly converted into a Mineral Reserve.
  • Average diamond value estimates are based on 2019 diamond sales data provided by the Company.
  • Mineral Resources have been estimated with no allowance for mining dilution and mining recovery.

Mineral Reserves

Karowe Mine 2021 Mineral Reserve Estimate (effective date of December 25, 2020)

Lobe - Type

Reserve Category

Ore
(Mt)

Carats
('000s ct)

Grade
(cpht)

Open Pit

       

North

Probable

0.4

38

9.5

Centre

Probable

2.7

403

15.2

South – EM/PK(S)      

Probable

2.3

574

25.0

South – M/PK(S)

Probable

7.8

828

10.5

Open Pit

Total

13.2

1,843

13.9

Underground

       

South – EM/PK(S)

Probable

16.3

3,246

19.9

South – M/PK(S)

Probable

17.1

1,807

10.6

Underground

Total

33.4

5,053

15.1

Stockpiles

       

Life of Mine

Probable

3.8

161

4.3

Mixed

Probable

3.5

381

10.8

Stockpiles

Total

7.3

542

7.4

Combined

       

All

Total

53.9

7,438

13.8

1.

Prepared by Gord Doerksen, P.Eng. JDS Energy & Mining Inc.

2.

CIM guidelines were followed for Mineral Reserves.

3.

Mineral Reserves are estimated based on an UG mining cost of US$9/t, a processing cost of US$16/t and a G&A cost of US$6/t. Process recovery of the diamonds was assumed to be 100% as the recoveries were included in the mineral resource block model assumptions and therefore have taken recoveries into account.  All of the kimberlite material in the South Lobe is above the cut-off value. Base of Probable Reserve is 310masl.

4.

Mineral Reserves are quoted above a +1.25mm bottom cut-off and have been factored to account for diamond losses within the smaller sieve classes expected within the current configuration of the Karowe Mine process plant.

5.

Diamond valuation was derived from historical sales adjusted for current and estimated future values.          

6. Tonnages are rounded to the nearest 100,000 tonnes; diamond grades are rounded to one decimal place. Tonnage and grade measurements are in metric units; contained diamonds are reported as thousands of carats.
7. All numbers have been rounded to reflect accuracy of estimate.