australia's identified mineral resources 2005 - Geoscience Australia

AUSTRALIA’S IDENTIFIED MINERAL RESOURCES 2005
DAP (20% P and 18% N) is used on broad-acre crops such as cereal, legume, fodder, horticultural
and row crops, and dairy and newly-established pastures. MAP (22% P and 10% N) assists with early
crop growth and enhances phosphorous uptake in broad-acre crops.
Resources
EDR of phosphate rock decreased by 5% in 2004 compared to the previous year. All EDR is
sedimentary phosphate rock (phosphorites), with an average grade of about 24% P 2 O 5 at Phosphate
Hill. The decrease resulted from production depletion and exclusion of small zones at the peripheries
of the Phosphate Hill deposit, which are no longer regard as practical to mine. There is no publicly
available information on Christmas Island’s phosphate resources. Geoscience Australia, however,
has reasonably detailed knowledge of this deposit and known resources remaining within the
existing mining lease on the island.
Most of Australia’s demonstrated resources of phosphate occur in the Georgina Basin and are
classified as paramarginal. Two deposits, Swan and Emu, occur within carbonatite at Mount Weld,
26 km southeast of Laverton (WA), where a phosphate-rich zone has formed by the solution and
weathering of a primary carbonatite.
The bulk of Australia’s inferred phosphate resources are in phosphorites in the Georgina Basin,
and these are distributed between Queensland, Western Australia and the Northern Territory.
Exploration
Data relating to exploration for phosphate are not available.
Production
Australia produced 2 039 kt of fertiliser in 2004 (649 kt DAP and 1 390 kt MAP). DAP came from rock
phosphate ore treated at WMC Resources’ Queensland Fertiliser Operations (QFO) at Phosphate
Hill. MAP was manufactured from domestic (Phosphate Hill) and imported rock phosphate.
World Ranking
Australia’s EDR of phosphate rock comprises less than 1% of the world’s total EDR of 18 Gt,
which occurs principally as sedimentary marine phosphorites.
Industry Developments
WMC Fertilisers’ QFO is the only Australian producer of DAP and MAP, both of which are sold in
Australia and overseas. Its major production-based operations – phosphate mine and beneficiation,
phosphoric acid, ammonia and granulation plants – are at Phosphate Hill. Supporting facilities are
located at Mt Isa (sulphuric acid plant) and Townsville (storage and ship handling facilities).
Ore reserves at Phosphate Hill are sufficient to support production for more than 30 years.
In 2004, WMC Fertilisers sold 75% of its fertiliser in Australia and 25% in Asia and produce a new
product, sulphur-fortified MAP, which is expected to capture greater marketing opportunities in the
future. Sulphur-fortified MAP provides a high-quality, low cadmium and low-heavy-metal alternative
for pastures and cropping requiring sulphur.
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Shale Oil
Oil shale is organic-rich shale that yields substantial quantities of oil (shale oil) by heating and
distillation. One tonne of oil shale may contain over 200 litres of oil. The organic material in oil shale
is kerogen, which can be a precursor to conventional oil reservoirs given appropriate conditions in
the crust. Australian oil shale deposits of commercial interest are predominantly in a series of narrow
and deep extensional-basins near Gladstone and Mackay in central Queensland. These are thick
Tertiary lacrustine (lake-formed) deposits that are relatively easy to mine. They contrast with
generally harder carbonate bearing oil shales (marls) found elsewhere in the world that are more
difficult to mine and process.