Lignite/ Brown Coal
Proven resource potential
Victoria hosts 430 billion tonnes of brown coal, representing a significant proportion of the world’s brown coal endowment.
More than 80 per cent of Victoria’s resource is located in the Gippsland Basin (South East Victoria), with seams in the Latrobe Valley region containing an estimated measured resource of 65 billion tonnes. Approximately half of this has been identified as potentially economic.
Brown coal production is dominated by mining at three mines in the Latrobe Valley - Hazelwood, Loy Yang and Yallourn.
In 2013-14, total production in Victoria amounted to 57.8 Mt.
|Victorian brown coal resources|
|Total estimated in situ brown coal in Victoria||430 billion tonnes|
|Measured brown coal in the Latrobe Valley||65 billion tonnes|
|Potentially economic brown coal in the Latrobe Valley||33 billion tonnes|
Found near the surface in thick seams, the resource lends itself to low-cost, large-scale open-cut mining. Lignite seams in the Latrobe Valley are up to 100 metres thick, with multiple seams often giving virtually continuous thickness of up to 230 metres. Seams are typically located under only 10-20 metres of overburden.
Lignite to overburden ratios (between 0.5:1and 5:1) in the Latrobe Valley area of the Gippsland Basin indicate a high tonnage of resource for every cubic metre of non-coal material mined.
Beyond the Gippsland Basin, other brown coal deposits can be found in the Otway Basin (mainly within the Bacchus Marsh, Altona and the Anglesea coalfields) and across the Murray Basin. Access to all sites is subject to the appropriate exploration and mining licenses.
Brown coal basics
Victoria’s lignite is typically low in ash, sulphur, heavy metals and nitrogen, making it very low in impurities by world standards. However, its high moisture content - which ranges from 48-70 per cent - reduces its effective energy content (average 8.6 MJ/kg on a net wet basis or 26.6 MJ/kg on a gross dry basis).
|Typical Characteristics of Victorian Lignite Brown Coal|
|Energy value (net wet)||5.8 to 11.5 MJ/kg|
|Energy value (gross dry)||25 to 29 MJ/kg|
|Overburden thickness||10 to 20 metres|
|Strip ratio (coal: overburden)||0.5 to 5:1|
|Water||48 to 70%|
|Carbon||65 to 70%|
|Oxygen||25 to 30%|
|Hydrogen||4 to 5.5%|
Low rank coal comparative
|Latrobe Valley||Puentes Spain|
|Megalopolis Greece||Dakota Texas U.S.A|
|Ptolemais Greece||Indonesian Low Rank|
|Neurath D, Germany||
||Net Specific Energy (MJ/kg)|
Source: Allardice Consulting Ltd