DISTRIBUTION OF URANIUM IN THE PRODUCTION OF TRIPLE SUPERPHOSPHATE (TSP) FERTILIZER AND PHOSPHORIC-ACID

In this study the distribution of uranium, which is one of the radioac tive elements present in phosphate fertilizers was investigated in dif ferent steps of the triple superphosphate (TSP) production process. Th e uranium in phosphate rock, phosphoric acid, phosphogypsum and TSP wa s extracted into the organic phase by using the TOPO extraction method . The uranium contents of these materials were determined by measuring the absorbance of the formed (pH 7.6) uranyl bromo-PADAP yl(2-(5-brom o-2-pyridylazo)-5-diethylaminophenol)] complex solutions at 574 nm aga inst blank. It was found that 50% of the uranium is dissolved in the a cid during the production of phosphoric acid while the remainder is pr ecipitated with phosphogypsum residue. The observations showed that in the second step, the sum of uranium in phosphate rock and phosphoric acid completely passed into TSP in the TSP manufacturing process.