South Australia has been proposed as a possible location for a uranium enrichment plant. The process considered most attractive for enrichment is the centrifuge process, which uses uranium hexafluoride, UF, as a feed material. Existing technology requires that the "tails" product from the enrichment plant, containing natural uranium and a depleted proportion of fissile uranium-235 is stored in cylinders as UF. The enrichment process therefore consumes considerable fluorine which is not available for recycle. Uranium hexafluoride is produced by the successive reaction of hydrogen fluoride and elemental fluorine (produced from hydrogen fluoride) upon a purified uranium dioxide. The quantity of hydrogen fluoride required for the proposed enrichment complex would involve a major expansion by existing producers or the construction of a new plant. On behalf of the South Australian Department of Mines, Amdel is investigating the feasibility of producing hydrogen fluoride from Australian resources. As Stage 1 of the investigation, Allen (1976) reviewed the sources of fluorine in Australia and the various processes available for the recovery of fluorine. His study concluded that of the various alternatives available, the following processes were most likely to be competitive with the existing method, in which imported acid-grade fluorspar is reacted with sulphuric acid. 1. Production of an acid-grade fluorspar from Australian fluorite ores by physical beneficiation, followed by reaction with sulphuric acid. 2. Production of hydrogen fluoride from a flurite ore via one of three processes which have been demostrated at laboratory or pilot scale but not commercially. The second stage of the investigation consists of an economic comparison of the following processes for producing hydrogen fluoride. 1. The reaction of imported acid-grade fluorspar with sulphuric acid by expansion of existing plants. 2. The production of acid-grade fluorspar from Australian fluorite ores for subsequent reaction with sulphuric acid at the existing (expanded) plants. 3. The chemical treatment of Australian fluorite ore via one of the following processes - A. Pyrohydrolysis B. Aluminium sulphate leaching C. Roasting with ammonium sulphate. The study was also intended to include the costs of processes for the recovery of fluorine from phosphate fertiliser plant exhaust gases, but it has not been possible to include these costs within the time and finance available.