Australia’s Estimated Ore Reserves

There are 2192 companies and securities listed on the Australian Securities Exchange (ASX) of which 852 (39%) are categorised as belonging to the materials and energy sectors, which includes mining and exploration companies. Recognising that confidence in such a large part of the Australian economy is paramount, the Joint Ore Reserves Committee of The Australasian Institute of Mining and Metallurgy, the Australian Institute of Geoscientists and the Minerals Council of Australia has developed the JORC Code for reporting Exploration Results and estimates of Mineral Resources and Ore Reserves to the public. The JORC Code has been adopted by the ASX as part of its listing rules and its use is mandatory for all mining companies listed on the ASX and New Zealand Stock Exchange. Variations of the JORC Code have been adopted in many other parts of the world and the code is compatible with the international CRIRSCO⁴ and United Nations Framework Classification for Resources templates.

As part of the Australian Government’s annual assessment of the national minerals inventory, Geoscience Australia compiles all known estimates of Ore Reserves and Mineral Resources reported publicly by mining companies in compliance with the JORC Code, or JORC-equivalent codes. In addition, reserve and resource estimates from private companies and foreign companies operating in Australia are also included in the annual compilation wherever possible.

Determining how much of a particular mineral commodity is in the ground and how much is extractable is not an exact science, hence Ore Reserves and Mineral Resources are always referred to as estimates, never calculations. Ore Reserves and Mineral Resources are categorised by confidence in both the geology of the deposit and the economic viability of production. Of all the different categories (see description of JORC Code on page 2), an Ore Reserve is the category of highest confidence. From a commercial point of view, this category is the most applicable to understanding the state of Australia’s minerals industry now and in the near future (say, the next five years).

Geoscience Australia began publishing amalgamated national totals for Ore Reserves in 2002. Prior to this, these estimates were included within the national inventory of EDR (and continue to be included) but were not specifically noted.

Operating Mines

In 2018, Australia had over 300 operating mines producing 26 major and minor mineral commodities. In addition, there were a large number of excavations for a range of industrial materials and gemstones (not covered in this publication). Mining contributed 8.4% to Australia’s gross domestic product in 2018⁵ and 46% of Australia’s export income. In determining the outlook for the industry in Australia, it is useful to look at the Ore Reserves and Mineral Resources associated with operating mines (Table 1) as it is usually easier and cheaper to expand current mines than to start new ones. While some of the mines that operated in 2018 have since closed or been placed on care and maintenance, subject to favourable economic, environmental and regulatory conditions, most will continue mining for the foreseeable future.

One way of gaining an impression of future viability of a mine or resource is to calculate the ratio of reserves or resources to production, thus establishing a reserve or resource ‘life’ (Table 1). The resulting reserve and resource life must be treated with caution as it is an average and it assumes three things: (1) that production rates in the future will remain the same as those used in the calculation, (2) deposits deemed economic/uneconomic remain so in the future and (3) that depleted resources are never replaced. In reality, production rates vary from year to year, mining companies continually reassess the economic viability of their deposits and companies typically do upgrade resources or discover new resources to replace ore depletion. Nonetheless, this ratio provides a potentially useful ‘snapshot in time’ that can help reveal trends in Australia’s ability to supply a range of mineral resources into the future.

Table 1. Australia's Ore Reserves and Mineral Resources of selected commodities at operating mines in 2018

Commodity	Unit	No. of Operating Mines¹	Ore Reserves²	Measured and Indicated Mineral Resources³	Inferred Mineral Resources⁴	Mine Production⁵	Reserve Life^a (years)	Resource Life 1^b (years)	Resource Life 2^c (years)
Antimony	kt Sb	1	17.3	40.9	15.4	3.57⁶	5	11	16
Bauxite	Mt	10	1956	3202	3646	96.5	20	33	71
Black Coal	Mt	95	12 592	26 030⁷	13 141⁷	578⁸	22	45	68
Copper	Mt Cu	36	19.13	72.32	30.97	0.920	21	79	112
Diamond	Mc	2	24.81	24.94	19.23	14.01	2	2	3
Gold	t Au	141	2872	6689	2458	315	9	21	29
Iron Ore	Mt	34	11 610	25 538	40 111	899	13	28	73
Lead	Mt Pb	15	10.61	24.25	4.42	0.469	23	52	61
Lithium	kt Li	7	2680	3295	1200	57⁹	47	58	79
Manganese Ore	Mt	3	92	196	29	7.0¹⁰	13	32	37
Mineral Sands
Ilmenite	Mt	12	15.3	56.1	14.8	1.4¹¹	11	40	51
Rutile	Mt	10	2.1	7.6	2.1	0.2¹¹	11	38	49
Zircon	Mt	10	4.5	13.4	2.9	0.5¹¹	9	27	33
Nickel	Mt Ni	12	1.1	5.5	1.1	0.148	7	37	45
Rare Earths¹²	Mt	2	1.71	2.12	1.37	0.019¹³	90	112	184
Silver	kt Ag	23¹⁴	19.64	53.30	12.27	1.220	16	44	54
Tin	kt Sn	1	167	224	97	6.9¹⁵	24	32	47
Uranium	kt U	3	258	1425	752	5.872	44	243	371
Zinc	Mt Zn	16	22.44	49.46	11.86	1.112	20	44	55

Abbreviations
t = tonne; kt = kilotonnes (1000 t); Mt = million tonnes (1 000 000 t); Mc = million carats (1 000 000 carats).
Where an element symbol follows the unit it refers to contained metal content.

Notes
a. Reserve Life = Ore Reserves ÷ Production.
b. Resource Life 1 = Measured and Indicated Resources ÷ Production.
c. Resource Life 2 = Measured, Indicated and Inferred Resources ÷ Production.

1. The number of operating mines counts individual mines that operated during 2018 and thus contributed to production. Some of these mines may belong to larger, multi-mine operations and some may have closed during or since 2018.

2. The majority of Australian Ore Reserves and Mineral Resources are reported in compliance with the JORC Code, however there are a number of companies that report to foreign stock exchanges using other reporting codes, which are largely equivalent. In addition, Geoscience Australia may hold confidential information for some commodities. NB: Not all operating mines report Ore Reserves. Ore Reserves are as at 31 December 2018.

3. Measured and Indicated Mineral Resources are inclusive of the Ore Reserves. NB: Not all operating mines report Mineral Resources. Mineral Resources are as at 31 December 2018.

4. Inferred Mineral Resources are as at 31 December 2018. NB: Not all operating mines report Mineral Resources.

5. Mining production from Resources and Energy Quarterly, June 2019, published by the Office of the Chief Economist, Department of Industry, Innovation and Science unless otherwise stated. Production data often have a higher level of certainty than reserve and resource estimates and, thus, may be presented with more significant figures.

6. Antimony production from company reports (Mandalay Resources Ltd).

7. Measured, Indicated and Inferred Mineral Resources for black coal are presented on a recoverable basis (these are Geoscience Australia estimates unless provided by the company).

8. Mine production refers to raw coal.

9. Lithium production data from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

10. Australian manganese production from company reports and total reported production from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

11. Mineral sands production from company reports.

12. Rare earths comprise rare earth oxides (REO) and yttrium oxide (Y₂O₃).

13. Rare earths production is based on Western Australian production of concentrates from Mount Weld (18 556 t) and from trial mining and processing at Browns Range (2.6 t).

14. Major silver producing mines only; many gold and copper mines also produce silver as a by-product but these are not counted here.

15. The Office of the Chief Economist reports tin production of 6.9 kt in 2018 but Renison, Australia’s only tin mine, reports 6.6 kt. Additional unreported production is as by-product from other operations such as Greenbushes.

Ore Reserves at other mines and deposits

This figure is a bar chart showing the percentage of Ore Reserves attributable to operating mines as a percentage of total Australian Ore Reserves 2018

Figure 1. Ore Reserves attributable to operating mines as a percentage of total Australian Ore Reserves 2018

Australia’s Identified Mineral Resources covers 36 mineral commodities, of which 30 have estimated Ore Reserves and 26 were actually in production in 2018 (Table 2). For many commodities (e.g. bauxite, copper and lead) the majority of Ore Reserves are associated with operating mines but Ore Reserves are also attributable to mines on care and maintenance, mines under development and, in some cases, undeveloped deposits (Figure 1). Australia’s graphite, potash and scandium sectors, for example, do not yet have operating mines so Ore Reserves are predominantly attributable to developing mines.

Table 2. Australia's Estimated Ore Reserves¹ as at December 2018

Commodity	Unit	Proved Ore Reserves	Probable Ore Reserves	Proved & Probable Ore Reserves²	Total Ore Reserves	Mine Production³	Reserve Life
Antimony	kt Sb	12.3	52.3	0	64.6	3.57⁴	18
Bauxite	Mt	1007	955	0	1962	96.5	20
Black Coal	Mt	8467	9354	1894	19715	578⁵	34
Brown Coal	Mt	n.a.	n.a.	n.a.	n.a.	48⁶	n.a.
Chromium	kt Cr	0	0	0	0	0	0
Cobalt	kt Co	196	437	1	635	4.9⁷	130
Copper	Mt Cu	6.13	15.47	0.77	22.38	0.920	24
Diamond	Mc	0	24.81	0	24.81	14.01	2
Fluorine	kt F	0	0	0	0	0	0
Gold	t Au	888	3100	29	4018	315	13
Graphite	Mt	0.28	4.89	0	5.17	0	0
Iron
Iron ore	Mt	8031	15 073	2	23 106	899	26
Contained iron	Mt Fe	3876	6664	1	10 540	557	19
Lead	Mt Pb	6.20	6.17	0	12.37	0.469	26
Lithium	kt Li	601	2788	0	3389	57⁸	59
Magnesite	Mt MgCO₃	10	3	24	37	<1⁹	187
Manganese Ore	Mt	46	30	17	92	7.0¹⁰	13
Mineral Sands
Ilmenite	Mt	27.7	32.7	0	60.3	1.4¹¹	43
Rutile	Mt	4.5	4.1	0	8.7	0.2¹¹	44
Zircon	Mt	11.0	11.1	0	22.1	0.5¹¹	44
Molybdenum	kt Mo	0	4.2	0	4.2	0	0
Nickel	Mt Ni	2.1	4.1	<1	6.2	0.148	42
Niobium	kt Nb	58	0	0	58	n.a.¹²	n.a.
Oil Shale	GL	0	0	0	0	0	0
PGE (Pt, Pd, Os, Ir, Ru, Rh)	t metal	0	0	0	0	0.541¹³	n.a.
Phosphate
Phosphate rock¹⁴	Mt	12	21	81	113	1.4¹⁵	81
Contained P₂O₅	Mt P₂O₅	2.0	7.0	20	29.0	n.a.	n.a.
Potash	Mt K₂O	1	2	0	3	0	0
Rare Earths¹⁶	Mt	1.65	1.19	0	2.84	0.019¹⁷	149
Scandium	kt Sc	5.52	6.61	0	12.14	0	n.a.
Silver	kt Ag	13.56	11.84	0	25.40	1.220	21
Tantalum	kt Ta	12.5	32.0	0	44.4	0.06¹⁸	740
Thorium	kt Th	0	0	0	0	0	0
Tin	kt Sn	35	214	0	249	6.9	36
Tungsten	kt W	21	195	0	216.0	<1¹⁹	>10 000
Uranium	kt U	90	203	3	296	5.872	50
Vanadium	kt V	740	442	0	1182	0	0
Zinc	Mt Zn	11.23	12.71	0	23.94	1.112	22

Abbreviations
t = tonne; kt = kilotonnes (1000 t); Mt = million tonnes (1 000 000 t); Mc = million carats (1 000 000 carats); GL = gigalitre (1 000 000 000 L); PGE = platinum group elements (Pt, Pd, Os, Ir, Ru, Rh).
Where an element symbol follows the unit it refers to contained metal content.

Notes
Reserve Life = Ore Reserves ÷ Production.
Figures are rounded so Proved, Probable and Proved & Probable Ore Reserves may not add up to Total Ore Reserves exactly.

1. The majority of Australian Ore Reserves are reported in compliance with the JORC Code, however there are a number of companies that report to foreign stock exchanges using other reporting codes, which are largely equivalent. In addition, Geoscience Australia may hold confidential information for some commodities.

2. 'Proved & Probable Ore Reserves' is a distinct reporting category that is no longer supported by the JORC Code. Some overseas reporting codes still use this category and some historical resources fall into this category.

3. Mining production from Resources and Energy Quarterly, June 2019 published by the Office of the Chief Economist, Department of Industry, Innovation and Science unless otherwise stated. Production data often have a higher level of certainty than reserve and resource estimates and, thus, may be presented with more significant figures

4. Antimony production from company reports (Mandalay Resources Ltd)

5. Black coal production refers to raw coal

6. Brown coal production is a Geoscience Australia estimate from company reports.

7. Cobalt production data from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

8. Lithium production data from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

9. The Department of State Development, South Australia (Report Book 2019/00009) reported magnesite production of 4587 t in 2018. The Queensland Department of Natural Resources and Mines (Queensland Annual Mineral Summary 2017–18) reported magnesite production of 258 859 t in 2017–18.

11. Minerals sands production from company reports.

12. There are no mines producing niobium as a primary product in Australia but it is likely produced as a by-product at some lithium/tantalum operations, but these data have not been reported.

13. Platinum and palladium production data from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

14. Phosphate rock is reported as being economic at grades ranging from 8.7% to 30.2% P₂O₅.

15. Geoscience Australia estimate based on reported mining production of 555 358 t from Christmas Island in 2018; 1040 t from South Australia in 2018 (Report Book 2019/00009); and 849 927 t from Queensland Department of Natural Resources and Mines (Queensland Annual Mineral Summary 2017–18).

16. Rare earths comprise rare earth oxides (REO) and yttrium oxide (Y₂O₃).

17. Rare earths production is based on Western Australian production of concentrates from Mount Weld (18 556 t) and from trial mining and processing at Browns Range (2.6 t).

18. Tantalum production data from Department of Mines, Industry Regulation and Safety, Western Australian Government, 2018–2019 Major commodities resources file.

19. Tungsten production from company correspondence (Tasmania Mines Pty Ltd).

National Classification System

The following terminology and definitions are used in Australia’s National Classification System for Identified Mineral Resources.

Resource: A concentration of naturally occurring solid, liquid, or gaseous materials in or on the Earth’s crust and in such form that its economic extraction is presently or potentially (within a 20–25 year timeframe) feasible.

Identified Resource: A specific body of mineral-bearing material whose location, quantity and quality are known from specific measurements or estimates from geological evidence for which economic extraction is presently or potentially (within a 20–25 year timeframe) feasible.

To reflect degrees of geological assurance, Identified Resources can be divided into Measured Resources, Indicated Resources and Inferred Resources where Measured Resources have the most geological confidence and Inferred Resources the least. The National Classification System’s definitions for Measured, Indicated and Inferred Resources are consistent with those of the JORC Code.

Under the JORC Code, with the application of Modifying Factors and mine planning, Measured Resources can be converted into Proved Ore Reserves or Probable Ore Reserves and Identified Resources can be converted into Probable Ore Reserves.

Demonstrated Resource: A collective term for the sum of Measured and Indicated Resources, including Proved and Probable Ore Reserves.

Economic: This term implies that, at the time of determination, profitable extraction or production under defined investment assumptions has been established, analytically demonstrated, or assumed with reasonable certainty.

Economic Demonstrated Resource (EDR): A Demonstrated Resource that is regarded as economic under the definition above. The EDR category provides a long-term view of what is likely to be available for mining (potential supply). It does not include Inferred Resources which do not have enough geological confidence to support mine planning. For shorter term, commercial viewpoints of the economic category see Table 1 (Ore Reserves and Mineral Resources at Operating Mines) and Table 2 (Australia’s Ore Reserves).

Subeconomic: This term refers to those resources that are geologically demonstrated but which do not meet the criteria of economic at the time of determination. Subeconomic Resources include paramarginal and submarginal categories:

Paramarginal: That part of Subeconomic Resources which, at the time of determination, could be produced given postulated limited increases in commodity prices or cost-reducing advances in technology. The main characteristics of this category are economic uncertainty and/or failure (albeit just) to meet the criteria of economic.
Submarginal: That part of Subeconomic Resources that would require a substantially higher commodity price or major cost-reducing advance in technology to render them economic.

Accessible Economic Demonstrated Resource (AEDR): Some resources have enough geological confidence to be considered a Demonstrated Resource and, in normal circumstances, would also be regarded as economic but they are not currently available for development because of legal and/or land-use restrictions. They are included in EDR but not in AEDR.

⁴ CRIRSCO is the Committee for Mineral Reserves International Reporting Standards.

⁵ See Footnote 2.