Manganese Ore

Please note that this page is currently under review.

Resource figures are current as at 31 December 2019.

Manganese (Mn) is the twelfth most abundant element in the Earth's crust. Amongst some 300 minerals containing manganese, only about a dozen are of economic significance. The two main manganese minerals are pyrolusite (MnO₂) and rhodochrosite (MnCO₃).

Manganese is the fourth-most used metal in terms of tonnage after iron, aluminium and copper and 90% of all manganese consumed annually goes into steel as an alloying agent. No satisfactory substitute for manganese has been identified which combines a relatively low price with outstanding technical benefits such as the ability to combine with sulphur and a powerful de-oxidation capacity.

After steel, the second most important market for manganese is in the form of electrolytic manganese dioxide and electrolytic manganese metal, both of which are used in the production of rechargeable electric vehicle (EV) batteries in association with lithium, cobalt and nickel. The growth in production of EVs and battery storage technology is stimulating the interest of existing manganese miners in project expansion, and of explorers in re-evaluating historical mine deposits and prospects for potential development.

Manganese is also an important alloying element with aluminium and copper, being used in plant fertilisers and animal feeds and as a colorant in glass and ceramics.

The use of manganese in many essential modern technologies has resulted in it being designated a critical mineral by a number of countries including Australia¹, the United States of America², Canada³ and Japan⁴. Critical minerals are those minerals (or elements) considered vital for the well-being of the world's economies, yet whose supply may be at risk of disruption.

JORC Ore Reserves

Ore Reserves of manganese were 91 million tonnes (Mt) in 2019, slightly down from 92 Mt the previous year (Table 1). Ore Reserves have been reported for the Woodie Woodie project in Western Australia and the Groote Eylandt and Bootu Creek projects in the Northern Territory.

The majority of Australian Ore Reserves and Mineral Resources are reported by industry in accordance with the Joint Ore Reserve Committee (JORC) Code⁵ to the Australian Securities Exchange. Where other reporting codes are used by companies listed elsewhere, these are also incorporated into the national inventory when they are largely equivalent.

Reserve life is calculated by dividing an Ore Reserve by that year's production. It can only be used for general impressions (see Table 2 footnotes for details) but is, nonetheless, a snapshot of potential future mineral supply that can be useful when considered cautiously.

A longer-term perspective on potential supply can be gained by using Economic Demonstrated Resources (EDR; Table 3) of manganese ore at all deposits, not just operating mines. Using the EDR for all deposits indicates that Australia could have approximately 35 years of manganese ore at 2019 rates of production.

Identified Resources

Australia's EDR of manganese ore have increased by 50% over the last decade from 181 Mt in 2009, to 272 Mt in 2019 (Table 3). Approximately 34% of EDR is comprised of Ore Reserves with the remainder drawn from Measured and Indicated Mineral Resource estimations. Projects that recorded an increase of EDR in 2019 were Butcherbird and Bootu Creek, whereas Groote Eylandt recorded a 6% decrease.

Geoscience Australia's mineral resources database is reviewed annually to evaluate the economic status of each individual deposit. Consideration is given to factors including, but not limited to, the probability of economic development, accessibility, location and commodity prices. An outcome of these reviews can be changes to mineral inventories as resource estimates are reclassified.

Developing projects, including the Butcherbird Project, which reported resource increases at the Richies Find, Coodamudgi and Mundawindi deposits⁶, have contributed to the 12% increase in Inferred Resources from 354 Mt in 2018 to 396 Mt in 2019.

Only the Northern Territory and Western Australia host EDR of manganese ore, respectively 57% and 43%. Western Australia also hosts significant subeconomic resources and Queensland has minor Inferred Resources in the Mount Isa region (Table 4). Figure 1 shows the locations and relative sizes of Australia's manganese deposits and mines.

Figure 1. Australian manganese deposits and operating mines as at 31 December 2019.
Deposit size is based on total resources (EDR + Subeconomic Demonstrated Resources + Inferred). For clarity, only major or significant deposits are labelled. Mt = million tonnes.

Accessible EDR

Some resources are inaccessible for mining because of environmental restrictions, government policies or because they occur within military lands or national parks. All of Australia's EDR of manganese ore (272 Mt) in 2019 is considered accessible (Table 3).

Production

In Australia, there are three operating mines (Figure 2) and one tailings re-treatment plant. The Woodie Woodie mine is located about 400 km southeast of Port Hedland in Western Australia. A manganese tailings processing plant also operates near the Woodie Woodie mine. The Northern Territory has two manganese mines with one being located on Groote Eylandt in the Gulf of Carpentaria and the other at Bootu Creek, 110 km north of Tennant Creek.

In 2019, Australia's manganese ore production totalled approximately 7.5 Mt (Table 2; Table 3). The total tonnage of manganese ore mined is approximately twice the tonnage produced because of yields of around 50% after beneficiation.

Export data for Australia's manganese products, including manganese ore, were not available.

Another potential manganese source in Australia is the Mount Thirsty Cobalt-Nickel Project, approximately 16 km northwest of Norseman, Western Australia, which is a joint venture between Conico Ltd and Barra Resources Ltd. The project's pre-feasibility⁷ study results stated that most of the cobalt and some nickel mineralisation is hosted by the secondary manganese oxide mineral asbolane⁸ The project's beneficiation study demonstrated several leaching processes with one showing successful extraction of cobalt and nickel and the precipitation of manganese as a by-product⁹.

World Ranking

In 2019, South Africa had the largest world economic resources of manganese at 31%, followed by Brazil and Ukraine (17% each). Australia ranked fourth with 14%, above Gabon and China with 7% each (Table 5).

South Africa also led world production of manganese, accounting for 29% of global demand in 2019, followed by Australia (17%) and Gabon (13%; Table 6).

Industry Developments

Exploration

While data associated with exploration expenditure for manganese are not published by the Australian Bureau of Statistics, Australian manganese producers and exploration companies are actively engaged in extending their knowledge at brownfield operations and discovering new sources of supply.

South32 Ltd reported the commencement of its exploration drilling program at GEMCO on Groote Eylandt during the first half of 2020¹². The company stated that it would infill drill the known mineralisation and also test other targets in the southern areas of the GEMCO operation.

In 2019, OM Holdings Ltd's exploration program at Bootu Creek drill-tested the newly discovered Carruthers North prospect, northwest of the Bootu Creek mine within tenement EL28604¹³ . Significant intersections include 7 m at 27.67% Mn from surface and 2 m at 37.41% Mn from 38 m in RSRC0321, and 5 m at 24.22% Mn from surface in RSRC0323¹⁴.

The 2019, drilling was also extended to the Renner West deposit where two diamond drill holes obtained core for metallurgical test work. The best intersections included:

• 4.8 m at 27.63% Mn from 4.0 m in RSDD001;
• 2.7 m at 28.2% Mn from 4.6 m, and 3.2 m at 33.65% Mn from 18.1 m in RSDD002; and
• 4.2 m at 26.81% Mn from 2.6 m, and 4.3 m at 33.98% Mn from 6.8 m in RSDD003¹⁵.

A joint venture between OM Holdings and Bryah Resources Ltd at the historic Horseshoe South manganese mine, Brumby Creek, Devils Hill and Black Cat prospects in Bryah Basin in Central Western Australia, has reported the completion of its Phase 1 drilling program. The program completed a total of 122 holes for 3,062 m of RC drilling¹⁶.

The best intersections included:

• 15 m at 26.2% Mn from 3 m at Brumby Creek;
• 12 m at 24.9% Mn from 7 m at Horseshoe South; and
• 7 m at 21.1% Mn from surface at Devils Hill.

The completion of the Phase 1 drilling program prompted planning of second phase of exploration activities for the December 2019 quarter¹⁷, including detailed ground mapping and high-resolution aerial photography¹⁸.

Citation

Bibliographical reference: Summerfield, D., 2021. Australian Resource Reviews: Manganese Ore 2020. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/9781922446541

References