Page 337 - Annual Report 2020

Proved oil and gas reserves SP (stockpile)
Those quantities of oil, gas and natural gas liquids, which by An accumulation of ore or mineral built up when demand
analysis of geoscience and engineering data can be estimated slackens or when the treatment plant or beneficiation equipment
with reasonable certainty to be economically producible – from is incomplete or temporarily unable to process the mine output; Strategic Report
a given date forward, from known reservoirs, and under existing any heap of material formed to create a buffer for loading
economic conditions, operating methods, and government or other purposes or material dug and piled for future use.
regulations – prior to the time at which contracts providing the Spud
right to operate expire, unless evidence indicates that renewal
is reasonably certain, regardless of whether deterministic or Commence drilling of an oil or gas well.
probabilistic methods are used for the estimation (from SEC Supergene Sulphide
Modernization of Oil and Gas Reporting, 2009, 17 CFR Parts 210, Supergene is a term used to describe near-surface processes and
211, 229 and 249). their products, formed at low temperature and pressure by the
Proved Ore Reserves activity of meteoric or surface water. Copper in Supergene
The economically mineable part of a Measured Mineral Resource. Sulphide is mainly provident from the copper bearing minerals
A Proved Ore Reserve implies a high degree of confidence in the chalcocite and covellite and is amenable to both grinding/flotation Governance at BHP
Modifying Factors. A Proved Ore Reserve represents the highest concentration and leaching processes.
confidence category of reserve estimate and implies a high degree Tailings
of confidence in geological and grade continuity, and the Those portions of washed or milled ore that are too poor to be
consideration of the Modifying Factors. The style of mineralisation treated further or remain after the required metals and minerals
or other factors could mean that Proved Ore Reserves are not have been extracted.
achievable in some deposits (JORC Code, 2012 Edition).
Qualified petroleum reserves and resources evaluator TLP (tension leg platform)
A vertically moored floating facility for production of oil and gas.
A qualified petroleum reserves and resources evaluator,
as defined in Chapter 19 of the ASX Listing Rules. Total Mineral Resources
Reserve Life The sum of Inferred, Indicated and Measured Mineral Resources. Remuneration Report
Current stated Ore Reserves estimate divided by the current Total Ore Reserves
approved nominated production rate as at the end of the The sum of Proved and Probable Ore Reserves.
financial year. Transitional Sulphide
ROM (run of mine) Transitional is a term used to describe the zone of mineralisation
Run of mine product mined in the course of regular mining that is a gradation between Supergene Sulphide and Hypogene
activities. Tonnes include allowances for diluting materials Sulphide resulting from the incomplete development of the former
and for losses that occur when the material is mined. as it overprints the latter. This results in a more irregular distribution
Slag of the three main copper bearing minerals and is amenable to both Directors’ Report
grinding/flotation concentration and leaching processes.
A by-product of smelting after the desired metal has been
extracted from its ore. UG (underground)
Slimes Below the surface mining activities.
A mixture of liquid and the finer particle sized fraction of minerals, Wet tonnes
typically related to tailings. Production is usually quoted in terms of wet metric tonnes (wmt).
Sludge To adjust from wmt to dry metric tonnes (dmt) a factor is applied
based on moisture content.
A thick, soft, wet mud or similar viscous mixture of liquid and solid
components, especially the product of minerals processing or
refining activities.
Smelting Financial Statements
The process of extracting metal from its ore by heating and melting.
Solvent extraction
A method of separating one or more metals from a leach solution
by treating with a solvent that will extract the required metal,
leaving the others. The metal is recovered from the solvent
by further treatment. 6

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BHP Annual Report 2020 335 Shareholder information