On sorption extraction of rare-earth elements in the nitric acid processing of Khibiny apatite concentrate

Fundamental aspects of the sorption recovery of rare-earth elements with a sulfocationite from a nitric-phosphoric acid solution formed as intermediate product in the nitric acid processing of Khibiny apatite concentrate were studied. It was confirmed that rare-earth elements can be effectively sorbed from a nitric-phosphoric acid solution without its preliminary neutralization. It was found that polyvalent metals can be sorbed from a nitric-phosphoric acid solution in the form of positively charged (possibly, single-charged) complexes containing nitrate and(or) phosphate ligands.