Content maintained by Mike Huleatt (inquiries to Steve Cadman)
Brown Coal |
AIMR 2012 |
Content maintained by Mike Huleatt (inquiries to Steve Cadman)
Brown coal, also called lignite, is a low rank, high moisture content coal which is used mainly to generate electricity. In Australia brown coal occurrences are known in all States and are Tertiary in age (15 to 50 million years old). The Gippsland Basin in Victoria contains a substantial world class deposit of brown coal with seams up to 330 metres 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.
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 1.
Table 1: Australia's recoverable resources of brown coal as at December 2010 (revised).
| Commodity | Units | JORC Reserves (% of Accessible EDR) |
Demonstrated | Inferred | Accessible EDR | ||
|---|---|---|---|---|---|---|---|
| Economic | Paramarginal | Submarginal | |||||
| Brown Coal - In situ | Million tonnes | 49 135 | 37 192 | 17 613 | 121 313 | ||
| Brown Coal - Recoverable | Million tonnes | N/A | 4 218 | 33 156 | 15 852 | 100 806 | 34 150 |
Recoverable Economic Demonstrated Resource (EDR) for December 2011 (Table 2) was 44 219 million tonnes (Mt) which was essentially the same as the revised estimate for 2010 shown in Table 1. Recoverable Paramarginal Demonstrated Resources (PDR) rose by less than 1% to 33 402Mt in 2011 while Subeconomic Demonstrated Resources (SDR) fell by 4% to 15 185Mt. Recoverable Inferred Resources were less than 1% lower than in 2010 at 100 664Mt. 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 2: Recoverable resources of brown coal in States and Northern Territory at December 2011 (million tonnes).
| State | JORC Reserves (% of Accessible EDR) |
Demonstrated | Inferred | ||
|---|---|---|---|---|---|
| Economic | Paramarginal | Submarginal | |||
| 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 | N/A | 44 219 | 33 402 | 15 185 | 100 664 |
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 150Mt at the 2011 rate of production is more than 500 years.
There are no publicly reported brown coal reserves that comply with the Joint Ore Reserve Committee (JORC) Code.
The Australian Bureau of Statistics does not report data relating to exploration expenditure for brown coal.
Australian brown coal production for 2010-11 reported by the Victorian Department of Primary Industries was 66.7Mt. 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.
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%).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:
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 480Mt over 60 years.