Manganese Ore

Michael Sexton (michael.sexton@ga.gov.au)

Manganese (Mn) is the twelfth most abundant element in the Earth's crust. Of approximately 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. Manganese is essential to iron and steel production by virtue of its sulphur-fixing, deoxidising and alloying properties. After its application in steel production, the most important market for manganese is dry cell batteries in the form of electrolytic manganese dioxide (EMD). It is an additive also in plant fertilisers and animal feed and as a colorant for bricks.

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

Manganese ore processing plants are operated by TEMCO at Bell Bay in Tasmania (Tas) and by Delta plc at Newcastle in New South Wales (NSW).

Resources

In 2011, Australia's Economic Demonstrated Resources (EDR) of manganese ore increased by 7% to 197 million tonnes (Mt), mainly because of a rise in EDR at Woodie Woodie (Table 10). Paramarginal Demonstrated Resources (PDR) remained unchanged at 23.1 Mt and Subeconomic Demonstrated Resources (SDR) also remained unchanged at 167 Mt. Inferred Resources increased by 136% to 313 Mt, mainly because of the announcement of an Inferred Resources increase at the Butcherbird Manganese Project in WA.

Table 10. Resources of manganese ore in the States and Northern Territory.
  Demonstrated
Economic
(Mt)
Demonstrated
Paramarginal
(Mt)
Demonstrated
Submarginal
(Mt)
Inferred
Undifferentiated
(Mt)
Queensland 0 0 0 0.2
Western Australia 46.1 23.1 167.0 262.6
Northern Territory 151.3 0 0 50.0
Total 197.4 23.1 167.0 312.8

Accessible EDR

All manganese ore EDR (197.4 Mt) is accessible. The resource life (resource to production ratio) is about 14 years at current rates of production of beneficiated manganese ore.

JORC Reserves

Manganese ore Joint Ore Reserve Committee (JORC) Code reserves are 143 Mt (72% of accessible EDR). The resource life based on JORC reserves, and at the current rate of production of beneficiated manganese ore, is about 10 years.

Exploration expenditure

Data associated with exploration expenditure for manganese are not published by the Australian Bureau of Statistics on either a State or National basis.

Production

The Bureau of Resources and Energy Economics (BREE) reported that Australia produced 6.96 Mt of beneficiated manganese ore in 2011 (6.5 Mt in 2010). The total tonnage of manganese ore mined is approximately twice the tonnage of beneficiated manganese ore produced (reported by BREE) because of yields of around 50% after beneficiation. Exports of manganese ores for 2011 totalled 6.9 Mt valued at $1369 million compared to 5.5 Mt valued at $1509 million in 2010.

World ranking

Australia has 12% of the worlds EDR of manganese ore and is ranked fifth behind the Ukraine (25%), South Africa (20%), Brazil (15%) and China (13%). Australia produces 17% of the world's manganese ore and is ranked second behind China (34%).

Industry Developments

Northern Territory

GEMCO: In 2011, GEMCO approved the US$279 million Phase 2 Expansion at its Groote Eylandt operation. This will increase the beneficiated manganese capacity at Groote Eylandt to 4.8 million tonnes per annum (Mtpa) from 4.2 Mtpa. First JORC estimates for the eastern leases were reported as part of further exploration intended to extend the life of the mine.

OM Holdings Ltd: The company's Bootu Creek plant has the capacity to produce 1 Mtpa annually, and 2011 resulted in record annual production of 902 kilotonnes (kt) which represents an increase 8.5% on 2010. Renner Springs, which is 70 km northwest of the Bootu Creek project, has undergone exploration and had its first JORC Inferred Resource estimate reported in 2011.

Western Australia

Consolidated Minerals Ltd: During 2011, the Woodie Woodie mine produced 3.2 Mt of manganese ore, a 14% increase on production for 2010. Exploration activities were positive, with a large increase in the mineral resource inventory. The Woodie Woodie product has high manganese content and very low phosphorus, while having very low degradation and high thermal stability.

Mineral Resources Ltd: The Nicholas Downs manganese project increased production capacity to 720 ktpa in 2011, with 449 kt exported from both Woodie Woodie operations at Peak Hill sites and the Nicholas Downs project.

Mesa Minerals Ltd: The Ant Hill and Sunday Hill projects are located 400 km south of Port Hedland. Both mines remained on care and maintenance throughout 2011.

Montezuma Mining Company Ltd: The Butcherbird Manganese project is located 120 km south of Newman. In 2011, the first JORC estimates were reported for eight deposits in the project, with a global Inferred Resource of 119 Mt reported, and a lower grade Inferred Resource of 55.9 Mt. A scoping study was conducted to investigate the development of a mine with capacity to produce up to 1 Mtpa.