Extraction of uranium from commercial phosphoric acid by DEHPA/TOPO process is a well-developed process on the commercial and pilot plant scale. Commercial phosphoric acid contains certain anions such as Cl − , F − and SO 2− 4 in varying concentrations. The presence of such anions could have a negative effect on the extraction process.This paper investigated the effect of Cl − , F − and SO 2−4 anions present in commercial wet phosphoric acid on the uranium extraction process. The effect of adding SiO 2 which complexes with F − and other anions was also studied. The results obtained showed that these anions formed complexes with UO 2+ 2 and therefore had a negative influence on the extraction of uranium from laboratory and commercial phosphoric acids. This effect was strong in the case of F − followed by SO 2− 4 and much less for Cl − . Addition of SiO 2 was found to negate the effect of F − and other anions and to exert a positive effect on uranium extraction. KeywordsExtraction · uranium · DEHPA/TOPO · anions · phosphoric acid AcknowledgementThe authors would like to express their thanks to the General