Assessment of Radiological Impact on the Environment During Recovery of Uranium from Phosphate Rocks and Phosphoric Acid

Abstract

Increasing demand for nuclear power has necessitated a fresh look at non-conventional sources of uranium such as phosphate rocks and phosphoric acid. Phosphate rocks are known to contain uranium around 50 to 200 parts per million (ppm); sometimes even up to about 800 ppm. About 150 million t of rock phosphates containing about 120 ppm of uranium amounting to a total of about 18,000 t of uranium are mined and processed around the world annually. The world potential for recovery of uranium from weak phosphoric acid is reported to be around 7000 t per annum. During production of phosphoric acid, while uranium goes with the acid, 226Ra and other environmentally important radionuclides emerge with the phosphogypsum. As all the decay products of uranium are present in the phosphate rocks, processing of large quantities of phosphate rocks has a potential for contamination of the surroundings with the enhanced natural radioactivity. An assessment of the potential exposure of workers to radiation and the impact on the environment from the radionuclides present in the rock phosphates and the product materials is considered important.KeywordsPhosphoric AcidPhosphate RockEnvironmental Impact AssessmentRadon ProgenyExemption LevelThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.