NT-QLD slurry pipeline options for Phosphate Australia

The A$200 million pipeline option was announced by Phosphate Australia, which is investigating three potential routes for a steel pipeline to reach the ocean from its 100 per cent-owned flagship project at Highland Plains, on the border of Queensland and the Northern Territory.
With a JORC compliant Inferred Resource of 56 million tonnes at 16 per cent phosphate, Phosphate Australia considers Highland Plains as a potential strong new contributor to Australia’s rock phosphate export profile – at a time the commodity is experiencing record demand globally from producers of agricultural fertilisers and animal feeds.
A scoping study estimated that the company could pipe its phosphate in a water-based solution over a distance of between 220 and 266 kilometres, for an operating cost of just A$2.06-$3.69 per tonne.
The study looked at three potential sites from which the phosphate could be stored and transported offshore by barge: Tully Inlet or Burketown in Queensland, or the Calvert River in the NT, directly north of Highland Plains.
“These findings completely change and enhance the potential economics of the Highland Plains project, both in terms of scale and operating costs,” Phosphate Australia’s managing director, Andrew James, said.
“As well as the extremely competitive operating costs, owning and operating such strategic infrastructure as this pipeline could put Phosphate Australia in a commanding and commercially powerful position in the region.”
James said the slurry pipeline initiative arose as a direct result of successful groundwater pump testing conducted at Highland Plains late last year, which discovered shallow groundwater with potential flow-rates of up to 25 litres per second.
The capital costs of building a 355 mm-diameter steel pipeline to reach the coast at one of the three proposed sites is estimated by the scoping study at between A$184 million and A$226 million.
“We will now undertake more detailed investigations into the individual merits of each of the three proposed pipeline routes, including their engineering and topographical challenges, potential environmental impacts, and heritage implications,” James said.
“Whichever route is chosen, Phosphate Australia will need to construct a barging and storage facility on the Gulf coast, complete with a dewatering plant to extract the rock phosphate from the water-based slurry.”
The company also announced “significant” improvements in tests to beneficiate – or upgrade – phosphate samples from Highland Plains, with flotation tests demonstrating recovery rates of up to 84.6 per cent for coarse samples and 52.3 per cent for fine samples.