Brown Coal

Brown coal, also called lignite, is a low rank high moisture content coal which is used mainly to generate electricity. In Australia, brown coal occurs in all States and is Tertiary in age (15 to 50 million years old). The Gippsland Basin in Victoria contains a substantial world class deposit of brown coal where seams can be up to 330 metres (m) thick. Currently, brown coal is only mined in Victoria where the open-cut mines at Anglesea, Loy Yang, Yallourn and Hazelwood supply coal to nearby power stations. Brown coal is also mined at Maddingley to produce soil conditioners and fertilisers. Other products from Victorian brown coal are briquettes for industrial and domestic use and low ash and low sulphur char products.

Resources

Continued analysis of the 2010 brown coal resource data identified an inconsistency in the processing of some 2010 data held in Geoscience Australia's database. Consequently a revised 2010 brown coal resource inventory was prepared and is shown in Table 4.

Table 4. Recoverable resources of brown coal in Australia as at December 2010 (revised).
Brown Coal JORC Reserves
(% of Accessible EDR)
Demonstrated
Economic
(Mt)
Demonstrated
Paramarginal
(Mt)
Demonstrated
Submarginal
(Mt)
INFERRED
(Mt)
Accessible
EDR
(Mt)
In situ   49 135 37 192 17 613 121 313  
Recoverable na 44 218 33 156 15 852 100 806 34 150

Recoverable Economic Demonstrated Resource (EDR) for December 2011 (Table 5) was 44 219 million tonnes (Mt) which was essentially the same as the revised estimate for 2010 shown in Table 4. Recoverable Paramarginal Demonstrated Resources (PDR) rose by less than 1% to 33 402 Mt in 2011 while Subeconomic Demonstrated Resources (SDR) fell by 4% to 15 185 Mt. Recoverable Inferred Resources were less than 1% lower than in 2010 at 100 664 Mt. Victoria accounts for just under 97% of Australia's identified resources of brown coal. Almost 99% of Australia's EDR is in Victoria with more than 90% in the Latrobe Valley.

Table 5. Recoverable resources of brown coal in Australia at December 2011.
State JORC Reserves
(% of Accessible EDR)
Demonstrated
Economic (Mt)
Demonstrated
Paramarginal
(Mt)
Demonstrated
Submarginal
(Mt)
Inferred
(Mt)
New South Wales          
Northern Territory          
Queensland          
South Australia     2 820 246 776
Tasmania     106    
Victoria   43 706 30 111 14 939 98 142
Western Australia   513 365   1 746
TOTAL AUSTRALIA na 44 219 33 402 15 185 100 664

Accessible EDR

Approximately 78% of brown coal EDR is accessible. Quarantined resources include the APM Mill site, which had a 50 year mining ban applied in 1980. Other quarantined resources include the coal under the town of Morwell and the Holey Plains State Park, both in Victoria. The resource life of the accessible EDR of 34 150 Mt at the 2011 rate of production is more than 500 years.

JORC Reserves

There are no publicly reported brown coal reserves that comply with the Joint Ore Reserve Committee (JORC) Code.

Exploration

The Australian Bureau of Statistics does not report data relating to exploration expenditure for brown coal.

Production

Australian brown coal production for 2010-11 reported by the Victorian Department of Primary Industries was 66.7 Mt. All production was from Victoria with the Latrobe Valley mines of Yallourn, Hazelwood and Loy Yang producing about 98% of Australia's brown coal. Other brown coal is mined at Anglesea for electricity generation for aluminium smelting and at Maddingley.

World Ranking

International data for world coal resources and production uses an aggregation of coal by rank which is different to that adopted in Australia. In terms of resources, international estimates refer to anthracite plus bituminous coal as one group and sub-bituminous coal and lignite as a second. Australian statistics for both resources and production refer to black and brown coal where black coal includes anthracite, bituminous and sub-bituminous coal and brown coal refers to lignite. Using the international categories Australia has 9.2% of the world's proven reserves of anthracite plus bituminous coal and 8.6% of the world's proven reserves of sub-bituminous coal plus lignite.

In terms of the Australian coal categories it is estimates that Australia has in the order of 19% of the world's recoverable brown coal EDR and ranks second behind the USA (20%). Australia produces about 7% of the world's brown coal and is ranked as the fifth largest producer after Germany (16%), Russia (8%), Turkey (7%) and China (7%).

Industry Developments

Brown Coal Innovation Australia (BCIA) funded research and development projects in brown coal low-emissions and product innovation technologies. BCIA's 2011 funding program included:

  • Research and development in emerging technologies for the capture of CO2 at a lower energy and cost penalty compared with existing technologies.
  • International collaboration to enable gasification for brown coal-fired power generation thereby reducing CO2 emissions and lowering generation costs.
  • Trials to determine the merits of using brown coal to improve soil health and plant yields.
  • Research of processing methodologies to reduce spontaneous combustion of dried or dewatered brown coal.
  • Determining the best and most cost-effective solvent absorbent technologies for the capture of CO2 emissions from brown coal.
  • Investigation by the CSIRO Advanced Coal Technology and Exergen Pty Ltd of high efficiency power generation using processed Victorian brown coal in an adapted diesel engine.
  • HRL Developments Pty Ltd - Kawasaki Heavy Industries Ltd project on the technical and economic merits of options for production of hydrogen, at both pilot and commercial-scale, from Latrobe Valley brown coal.

Mantle Mining Corporation Ltd reported that it had intersected coal in the first four holes of a 15-hole drilling program at Bacchus Marsh which was aimed at defining an Inferred Coal Resource at the project. The cumulative coal thicknesses intersected in the first four holes were more than 25% greater than was predicted from modelling historic drilling in the area. Analyses of the coal showed that the Bacchus Marsh coal has lower moisture content and higher nett wet calorific values than those of the Latrobe Valley and therefore may be of a higher rank. Mantle also entered preliminary agreements to develop the deposit with Exergen Pty Ltd which has developed a brown coal dewatering technology. Trials on Bacchus Marsh coal confirmed that the technology could result in 56.7% coal moisture being reduced to 9.5% briquette moisture.

Blackham Resources Ltd reported encouraging results from preliminary coal upgrading tests on brown coal samples from the planned open pit area of the Scaddan deposit in Western Australia. They indicated that the coal could be dried to less than 0.01% moisture with an expectation that it would reabsorb 7¿¿¿8% moisture resulting in a gross wet calorific value of 19.6 megajoules per kilogram (MJ/kg). Blackham finalised a scoping study for the export of Scaddan coal through Esperance. The study examined several options with the two preferred being Option 1 with 8 million tonnes per annum (Mtpa) production shipped through an expanded bulk Port of Esperance with Blackham paying its additional port capital requirements and Option 2 with 8 Mtpa production shipped through an expanded bulk Port of Esperance with an infrastructure group paying additional port capital requirements and Blackham paying an additional tariff to access the third party infrastructure.

The mine plan called for coal production of 480 Mt over 60 years.