PROCESS FOR REDUCING THE RADIOACTIVITY OF PHOSPHORUS CONTAINING CHEMICAL FERTILIZERS

摘要

The invention relates to a process for reducing natural radioactivity during the processes for preparing phosphorus containing fertilizers, also recovering uranium and rare earths. According to the invention, the process consists in settling the radium with barium sulphate, retaining the radium as residue, by filtering, followed by extracting the uranium, rare earths, vanadium, iron, chromium etc with di(2-ethylhexyl)phosphate ester and tri-n-octylphosphinic or tributylphosphinic oxide - using as diluent an aliphatic hydrocarbon, separating the extract from phosphonitric solutions or phosphoric acid having a low reactivity and passing it through a plurality of stirring, separating and stripping stages for producing by successive filtrations first a rare earth concentrate and then a uranium concentrate, and recirculating the depleted extract of uranium and rare earth, thereafter.