Potash

Content maintained by Yanis Miezitis

• Potash
• Resources
• JORC Reserves
• Exploration
• Production
• World Ranking
• Industry Developments

The term potash refers to potassic fertilisers, which are potassium chloride (KCl or sylvite), potassium sulphate [K₂SO₄ or sulphate of potash (SOP), which usually is a manufactured product], and potassium-magnesium sulphate [K₂SO₄•2MgSO₄ or either langbeinite or double sulphate of potash magnesia (SOPM or K-Mag)]. Muriate of potash (MOP) is an agriculturally acceptable mix of KCl (95% pure or greater) and sodium chloride (halite) for fertilizer use, which includes minor amounts of other nontoxic minerals from the mined ore and is neither the crude ore sylvinite nor pure sylvite.

Historically Australia has always been deficient in known resources of potash. For this reason Geoscience Australia has not compiled national scale resource information on potash because there has not been sufficient to record. Also, exploration has not been successful in locating commercially significant resources of potash.

However, sharp increases in the price of potash prior to the global financial crisis in late 2008 and the first half of 2009 encouraged exploration for potash and resources have been published recently for Lake Disappointment, Lake Chandler and in the Western Australia (WA) portion of Lake Mackay.

Currently there are no Joint Ore Reserve Committee (JORC) Code reserves for potash resources.

Interest in exploration for potash continued in 2010 in Lake Disappointment, Lake Mackay, south Carnarvon Basin, Perth Basin and Canning Basin in WA as well as the Adavale Basin in Queensland (Qld) and in the Barrow Creek area in the Northern Territory (NT).

According to United States Geological Survey (USGS), about 93% of the world potash production in 2009 was consumed by the fertilizer industry. Potassium chloride is the main fertilizer product, containing an average 61% of K₂O equivalent. In 2010, the main producers of potash were Canada with 9.5 million tonnes (Mt) followed by Russia (6.8Mt) and Belarus (5.0Mt). The three accounted for about 65% of the world production of 33Mt, which was up from 20.8Mt in 2009.

In Australia, some minor historic production of potash include an operation at Buladelah Mountain, New South Wales, where alunite KAl₃(SO₄)₂(OH)₆, was mined during 1890 to 1926 and again from 1935 to 1952, for a total production of 75 000 tonnes. Crude potash in form of soluble salt glaserite (K,Na)₂SO₄, was produced from Lake Chandler during 1943 to 1950 for a total of 9218 tonnes of glaserite.

In 1973, Geoscience Australia's predecessor, the Bureau of Mineral Resources, reported that Texada Mines Pty Ltd was working towards becoming Australia's first local potash producer in the form of langbeinite K₂Mg₂(SO₄)₃ at Lake Macleod, northwest WA. The planned capacity of the proposed plant was variously reported to be from 80 000 to 200 000 tonnes per annum (tpa). There is no record of production of potash from the proposed operation.

Australia imports all of its potash requirements and according to the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) Australian Commodity Statistics 2010, the imports of potassium fertiliser amounted to 210.6 kilotonne (kt) in 2007-08 and 339.8kt in 2008-09.

According to the USGS the countries with the largest economic resources of potash (K₂O) were Canada 4.4 gigatonnes (Gt), which represents about 46% of the total world resource, followed by Russia with 3.3Gt (35%) and Belarus with 0.75Gt (8%).

Lake Disappointment: Located in the Gibson Desert of WA about 320 kilometres east of Newman, Lake Disappointment is a modern playa lake covering approximating 1600 square kilometres . Potash mineralisation occurs in lacustrine sediments of the lake and in the entrained brine.

On 13 March 2007, Reward Minerals Ltd published a lower estimate of 7705Mt Indicated Resource at 3.17 kilograms/tonne (kg/t) K₂SO₄ containing 24Mt K₂SO₄ and an upper estimate of 8635Mt at 3.17kg/t K₂SO₄ containing 27.37Mt K₂SO₄. The difference between the upper and lower figure is the result of assumptions about the depth and area for the lake margins.

On 23 December 2011, Reward Minerals Ltd advised that it had reached agreement with the Western Desert Lands Aboriginal Corporation (WDLAC) and the Martu people on the terms of a Mining and Indigenous Land Use Agreement (ILUA) for the company's Lake Disappointment potash project. The company is planning to advance the project as rapidly as possible by recommencing activities on the project, including undertaking a resource upgrade as well as feasibility activities and a Clearance Heritage Survey scheduled to occur in March 2012.

Lake Chandler: On 29 January 2009, ActivEX Limited announced a JORC compliant Inferred Resource of 5.779025Mt of ore at 5.73% K₂O at its Lake Chandler potash deposit situated 45km north of Merredin and 300km east of Perth in WA. The company reported in its 2010 annual report that it carried out a scoping study on a nominal throughput of 200 000tpa to give the project a mine life of 25 years. The company concluded that the study showed that, with the softness of the potash market, the project would be only marginal under current economic conditions.

Lake Mackay: Situated in the Gibson Desert, straddling the WA-NT border 50km north of the Tropic of Capricorn, Lake MacKay is a modern, playa lake with a surface area of more than 2250 square kilometres. Reward Minerals reported in its 2009 annual report that it has delineated a JORC Code compliant, Inferred Resource at Lake MacKay of 4780.4 million bench cubic metres (BCM) at 4.3kg of K₂SO₄ (SOP) per BCM for a total of 20.56Mt of K₂SO₄.

The resource estimate was calculated on the basis of lakebed sediment volume of BCM to a depth of two metres and the water soluble potassium sulphate content of the sediments that lie within the company's tenement holdings.

The company reported that the next stage of development at Lake Mackay would involve the construction of pilot ponds and pump testing as well as flow sheet development for the compilation of a feasibility study. The company reported that the programs would depend on agreement with the traditional land owners¹.

Dandaragan Greensands Project: Potash West NL is exploring the potential for producing potash from greensand deposits in the Perth Basin which are located between 50 and 230km north of Perth². The company is investigating the possibility of using conventional magnetic separation techniques to separate glauconite from greensands and is conducting laboratory scale testing to produce marketable potash products from glauconite concentrate³.

Karinga Creek Project: Rum Jungle Resources Ltd in a joint venture with Reward Minerals Ltd was analysing potassium, magnesium and sulphate levels in aquifers surrounding Karinga Creek Salt Lakes, about 225 kilometres southwest of Alice Springs in the NT⁴.

1. Reward Minerals Ltd, 2011. Reward Minerals Ltd annual report 2010. 64 pp.
2. Potash West NL, 2010.  Prospectus, 96 pp.
3. Potash West NL, 2012. Potash West succeeds in producing potash from WA glauconite deposits. Announcement to the Australian Securities Exchange, 23 January 2012, 3 pp.
4. Rum Jungle Resources Ltd, 2011. Karinga Creek potash update. Announcement to the Australian Securities Exchange 20 December, 2010. 6 pp.