Oxidation of alkyl radicals in $gamma;-transitions of amorphous substances

Abstract

Recovery of uranium from phosphoric acid on a commercial scale was first attempted in 1952 in the United States; at a plant operated by the Blockson Chemical Co. in Joilet, Ill, and used a chemical precipitation technique to recover the uranium as uranous phosphate. This plant was followed by two others, both in the United States. These plants started operating in 1955 and 1957, and both used octy-pyro-phsophoric acid as a solvent. While it was inexpensive, it had a short life and had to be replaced daily. All three uranium recovery plants were operated for several years until the price of uranium fell.With the large increase in the cost of energy in the mid-1970s, the price of uranium also rose. In the United States, where the indigenous phosphate rock contains relatively high uranium concentrations, the proposition of recovering it from phosphoric acid again became attractive; as a result 8 plants were built. (6 in Florida and 2 in Louisiana) Subsequently, plants were also built in Canada, Spain, Belgium, Israel, Iraq, Iran, and Taiwan. Again the price of uranium fell and most of the plants shut down quickly as they could not operate at a profit. However, at least 4 plants had long term contracts with United States utilities and were able to operate quite profitably for 10-15 years. During these years they were able to improve the process economics and efficiency. Operating costs of these plants were in the $11-13/pound range.Even though there may not have been any operating plants after 1997, research on the recovery of uranium from phosphoric acid did not stop. If any new plants are to be built, most likely they will be based on solvent extraction as this is the most proven and still the most economic process.