Page 336 - Annual Report 2020

Heap leach(ing) Metallurgical coal
A process used for the recovery of metals such as copper, nickel, A broader term than coking coal, which includes all coals
uranium and gold from low-grade ores. The crushed material used in steelmaking, such as coal used for the pulverised
is laid on a slightly sloping, impermeable pad and leached coal injection process.
by uniformly trickling (gravity fed) a chemical solution through MGSSA
the beds to ponds. The metals are recovered from the solution. Member of the Geological Society of South Africa.
Hypogene Sulphide Mineral Resources
Hypogene mineralisation is formed by fluids at high temperature
and pressure derived from magmatic activity. Copper in Hypogene A concentration or occurrence of solid material of economic
Sulphide is mainly provident from the copper bearing mineral interest in or on the Earth’s crust in such form, grade (quality) and
chalcopyrite and higher metal recoveries are achieved via grinding/ quantity that there are reasonable prospects for eventual economic
flotation concentration processes. extraction. The location, quantity, grade (or quality), continuity
and other geological characteristics of a Mineral Resource are
Indicated Mineral Resources known, estimated or interpreted from specific geological evidence
That part of a Mineral Resource for which quantity, grade (or quality), and knowledge, including sampling (JORC Code, 2012 Edition).
densities, shape and physical characteristics are estimated with Mineralisation
sufficient confidence to allow the application of Modifying Factors
in sufficient detail to support mine planning and evaluation of Any single mineral or combination of minerals occurring in a mass,
the economic viability of the deposit (JORC Code, 2012 Edition). or deposit, of economic interest.
Inferred Mineral Resources Modifying Factors
That part of a Mineral Resource for which quantity and grade Considerations used to convert Mineral Resources to Ore Reserves.
(or quality) are estimated on the basis of limited geological These include, but are not restricted to, mining, processing,
evidence and sampling. Geological evidence is sufficient to metallurgical, infrastructure, economic, marketing, legal,
imply but not verify geological and grade (or quality) continuity environmental, social and governmental factors.
(JORC Code, 2012 Edition). NGL (natural gas liquids)
Joint Ore Reserves Committee (JORC) Code Consists of propane, butane and ethane – individually or as a mixture.
A set of minimum standards, recommendations and guidelines Nominated production rate
for public reporting in Australasia of Exploration Results, The approved average production rate for the remainder of the
Mineral Resources and Ore Reserves. The guidelines are defined life-of-asset plan or five-year plan production rate if significantly
by the Australasian Joint Ore Reserves Committee (JORC), different to life-of-asset production rate.
which is sponsored by the Australian mining industry and
its professional organisations. OC (open-cut)
Leaching Surface working in which the working area is kept open to the sky.
The process by which a soluble metal can be economically Ore Reserves
recovered from minerals in ore by dissolution. The economically mineable part of a Measured and/or Indicated
LNG (liquefied natural gas) Mineral Resource. It includes diluting materials and allowances for
losses, which may occur when the material is mined or extracted
Consists largely of methane that has been liquefied through and is defined by studies at Pre-Feasibility or Feasibility level
chilling and pressurisation. One tonne of LNG is approximately as appropriate that include application of Modifying Factors.
equivalent to 46,000 cubic feet of natural gas.
LOI (loss on ignition) Such studies demonstrate that, at the time of reporting, extraction
could reasonably be justified (JORC Code, 2012 Edition).
A measure of the percentage of volatile matter (liquid or gas) PCI
contained within a mineral or rock. LOI is determined to calculate
loss in mass when subjected to high temperatures. Pulverised coal injection.
LPG (liquefied petroleum gas) PEGBC
Consists of propane and butane and a small amount (less Association of Professional Engineers and Geoscientists of the
than 2 per cent) of ethane that has been liquefied through Province of British Columbia.
pressurisation. One tonne of LPG is approximately equivalent Probable Ore Reserves
to 12 barrels of oil. The economically mineable part of an Indicated and, in some
MAIG circumstances, a Measured Mineral Resource. The confidence
Member of the Australian Institute of Geoscientists. in the Modifying Factors applying to a Probable Ore Reserve is
Marketable Coal Reserves lower than that applying to a Proved Ore Reserve. Consideration
of the confidence level of the Modifying Factors is important in
Represents beneficiated or otherwise enhanced coal product conversion of Mineral Resources to Ore Reserves. A Probable Ore
where modifications due to mining, dilution and processing have Reserve has a lower level of confidence than a Proved Ore Reserve
been considered, must be publicly reported in conjunction with, but is of sufficient quality to serve as the basis for a decision
but not instead of, reports of Coal Reserves. The basis of the on the development of the deposit (JORC Code, 2012 Edition).
predicted yield to achieve Marketable Coal Reserves must be
stated (JORC Code, 2012). Propane
MAusIMM A component of natural gas. Where sold separately, is largely
propane gas that has been liquefied through pressurisation.
Member of the Australasian Institute of Mining and Metallurgy. One tonne of propane is approximately equivalent to 19,000
Measured Mineral Resources cubic feet of gas.
That part of a Mineral Resource for which quantity, grade
(or quality), densities, shape and physical characteristics are
estimated with confidence sufficient to allow the application
of Modifying Factors to support detailed mine planning
and final evaluation of the economic viability of the deposit
(JORC Code, 2012 Edition).

334 BHP Annual Report 2020