Uranium and Radium-226 in Florida Phosphate Materials

Abstract

Input materials, products and by-products from a number of Florida phosphate mines and chemical plants were analyzed for '=Ra and 238U by high resolution gamma spectrometry. Concentrations were distinctly lower in North Florida than in Central Florida. In the matrix, the two nuclides were essentially in radioactive equilibrium (North Florida, 8 pCi/g; Central Florida, 38 pCi/g). Following beneficiation, concentrations in rock product, waste clays and sand tailings were approx. 100-300%, 100% and 10-25%, respectively, of those in the matrix. Radioactive equilibrium is markedly disrupted in phosphoric acid production; uranium follows the phosphoric acid while '=Ra appears in the by-product gypsum (North Florida, 14 pCi/g; Central Florida, 26 pCilg) and also in sediments and scales. Ammoniated phosphate fertilizers had relatively low levels of '=Ra but significant 238U (North Florida, 25 pCilg; Central Florida, 70 pcilg). On the other hand, triple superphosphate had significant concentrations of both (North Florida, 12 pCi/g; Central Florida, 20 pCilg) and u8U (North Florida, 26 pCi/g; Central Florida, 56 pcilg). In the electric furnace process, radioactivity is transferred to the slag (Central Florida, 61 pCilg of each nuclide). Within either region, nearly all sample types showed a considerable range of concentrations.

Natural Radioactivity and dose Assessment in Sand and Sediment Samples from Kuakata Beach, Bangladesh

“…Prior to the measurement of the samples, the environmental gamma background at the laboratory site was determined with an identical empty plastic container used in the sample measurement. (Roessier et al 1970).…”

Background Gamma Radiation Mapping in Bangladesh: Radioactivity in the Surface Soil of ‘BhawalGahr’ Area of Gazipur

“…Prior to the measurement of the samples, the gamma background at the laboratory site was determined with an identical empty plastic container used for the measurement of the samples. Th and 1460 keV for 40 K [10][11].…”

Impacts of Terrestrial Ionizing Radiation on the Hematopoietic System

“…In some countries (e.g., Finland) the average dose is several times higher, and in particular, residents of many countries have received effective doses of the order of hundreds of milisieverts per year [19,20]. Uranium is a natural radioactive and chemotoxic heavy metal found in traces in soils, rocks, and plants, as well as in water sources [23][24][25][26]. Uranium-238 is the parent to a long series of radionuclides of several elements.…”