Page 305 - Annual Report 2020

(1) Cut-off criteria: (5) Approximate drill hole spacings used to classify the reserves were:
Deposit Ore Type Mineral Resources Ore Reserves Deposit Proved Reserves Probable Reserves Strategic Report
Leinster OC ≥ 0.40%Ni ≥ 0.40%Ni Leinster 25m x 25m 25m x 50m
Disseminated ≥ 0.40%Ni − Mt Keith 40m x 40m 80m x 80m
Sulphide Cliffs 25m x 25m 25m x 25m
UG ≥ 1.0%Ni ≥ 0.90%Ni (and development)
Oxide ≥ 1.2%Ni − Yakabindie 40m x 60m 80m x 60m
SP, SP oxidised ≥ 0.70%Ni − Venus 25m x 25m 50m x 50m
Mt Keith Disseminated Variable between − (6) Ore delivered to the process plant.
Sulphide 0.35%Ni and 0.40%Ni (7) Metallurgical recoveries for the operations were:
SP Variable between Variable between Deposit Metallurgical Recovery
0.35%Ni and 0.40%Ni 0.35%Ni and
and ≥ 0.18% 0.40%Ni and Leinster OC 80%
recoverable Ni ≥ 0.18% Governance at BHP
recoverable Ni Mt Keith 63%
OC − Variable between Cliffs 83%
0.35%Ni and Yakabindie 63%
0.40%Ni and
≥ 0.18% Venus 88%
recoverable Ni (8) Predicted metallurgical recoveries for the projects were:
Cliffs Disseminated ≥ 0.40%Ni −
Sulphide Deposit Metallurgical Recovery
Massive Sulphide Stratigraphic − Leinster UG 88%
UG − ≥ 1.2%Ni (9) Leinster – Ore Reserves includes operations and projects.
Yakabindie Disseminated ≥ 0.40%Ni − (10) Leinster – The increase in the OC ore type was due to improved resource
classification which enabled increase conversion to Ore Reserves.
Sulphide The decrease in the Reserve Life was due to an increase in the nominated Remuneration Report
OC − ≥ 0.35%Ni production rate from 0.6Mtpa to 1.4Mtpa. Incorporated within the Reserve Life
Venus Disseminated ≥ 0.40%Ni − calculation were OC and UG ore types, which contribute 3 years and 8 years
respectively.
Sulphide (11) Mt Keith – The decrease in Ore Reserves was mainly due to depletion.
Massive Sulphide Stratigraphic − The increase in Reserve Life was due to a decrease in nominated production
rate from 8Mtpa to 6Mtpa.
UG − ≥ 0.9%Ni (12) Cliffs – The increase in Ore Reserves and Reserve Life was mainly due to an
Jericho Disseminated ≥ 0.40%Ni − update in the mine design.
Sulphide (13) Yakabindie – The increase in Ore Reserves was mainly due to an update in the
mine design.
(2) Leinster – The increase in OC ore type was due to an update in the resource (14) Venus – The increase in Ore Reserves and Reserve Life was mainly due to
estimate supported by additional drilling. The decrease in SP ore type was due changes in mining method from Longhole Open Stope to Sub-Level Cave.
to depletion.
(3) Mt Keith – The decrease in SP ore type was due to depletion. Directors’ Report
(4) Venus – The increase in Disseminated Sulphide ore type and decrease in
Massive Sulphide ore type was due to an update in the resource estimate
supported by additional drilling.

Financial Statements

6

Additional information

BHP Annual Report 2020 303 Shareholder information