The decision comes after several years of investigation into manufacturing solutions to tackle odour issues associated with processing certain types of phosphate rock that, until now, have limited feedstock sources for the company.

CSBP Managing Director Ian Hansen said that the company currently sourced between 60 and 70 per cent of its phosphate rock from the Boucraa region of Western Sahara.

Mr Hansen said that the high phosphorus content and good processing characteristics of phosphate rock from Boucraa made it ideal for manufacturing single superphosphate without unpleasant processing side-effects.

“Our sources of phosphate rock are restricted to several locations due to a range of technical issues including non-toxic odour produced during processing,” Mr Hansen said.

“The RTO will oxidise waste gas to address odour issues associated with processing phosphate rock from new sources.”

“This will allow CSBP to diversify its feedstock for superphosphate manufacture and reduce the company’s reliance on phosphate rock from its current key supply region, Western Sahara.”

Mr Hansen said that CSBP was aware of concerns about the long-running dispute over sovereignty of Western Sahara and had engaged in dialogue with interested parties about the company’s purchase of phosphate rock from the region for some time.

“While there is no doubt that broadening our supplier base for the benefit of our business has been the main reason for taking this investment decision, we have also considered the views and needs of a range of stakeholders, including those concerned with the current situation in Western Sahara,” Mr Hansen said.

“We have continued to import product from Western Sahara based on legal advice and the fact that the Australian Government imposes no trading restrictions on the region.”

Mr Hansen said the new technology would allow the company to vary the blend of phosphate rock while continuing to meet environmental and quality standards.

“We will determine phosphate rock blends and supply options once the RTO has been installed, tested and proven,” Mr Hansen said.

“The installation of the RTO does not necessarily foreshadow a complete end to imports of phosphate rock from Western Sahara because factors such as the operational efficiency of the new technology, and the price and reliability of alternative sources will all have to be taken into account when considering future supply arrangements.”

Design and construction of the RTO will take approximately two years, with design work expected to start before the end of the year.

CSBP is the largest supplier of fertilisers to the agricultural sector in Western Australia and is the only WA manufacturer of single superphosphate.