The amount of phosphoric acid produced in Australia has decreased significantly in recent times, not least due to the reduction of supplies of cheap phosphate rock from Christmas Island and Nauru.
Western Australia has a phosphate deposit at Mount Weld, 25 kilometres south of Leonora. Confirmed reserves are at 80 million tonnes with a further 170 million tonnes inferred. The rock is extremely hard and contains about 41% diphosphorous pentoxide (P2O5).
Nauru is best known in Australia for being part of the ‘Pacific solution’ with a detention centre for refugees being operational between 2001 and 2007. It is a tiny island nation with less than 10 000 inhabitants, producing up to two million tonnes of rock phosphate containing 38% of P2O5 per year. The reserves of phosphate have almost been entirely used up, leaving 80% of the island’s land area barren and severely scarred by the result of phosphate mining.
Australia now imports most of its phosphate rock from other countries, including the United States of America and Morocco.
Sulfuric acid, which can be used in this process, is produced in Western Australia in large quantities at Kwinana, and also on a smaller scale in Kalgoorlie where sulfur dioxide, produced as a potential toxic by-product in the extraction of nickel, is used instead to manufacture the sulfuric acid.