METHOD OF EXTRACTING LANTHANIDES FROM WET-PROCESS PHOSPHORIC ACID Russian patent published in 2012 - IPC C01F17/00 

FIELD: chemistry.

SUBSTANCE: method of extracting lanthanides from wet-process phosphoric acid, containing fluorine, aluminium, silicon, titanium and iron trace constituencies, involves addition of a precipitation agent to heated acid to form a suspension and turning the main portion of lanthanides and a portion of the trace constituencies into a solid phase, separation of the solid phase from the phosphate solution and washing said solid phase. The precipitation agent used is a phosphoric acid-soluble compound containing a fluoride ion. The precipitation agent is added to the acid in concentration which, with respect to the fluoride ion, is determined using the relationship: A=n·(2.235a₁+1.9a₂+1.425a₃+1.425a₄+0.348a₅-a₆), where A is concentration of the fluoride ion, g/l, n is a stoichiometry coefficient, n=1-3, a₁, a₂, a₃, a₄, a₅, a₆ is initial concentration of Al₂O₃, SiO₂, TiO₂, Fe₂O₃, ΣLn₂O₃ and fluorine in acid, respectively, g/l.

EFFECT: invention simplifies and cuts duration of extraction of lanthanides and enables extraction of lanthanides from recycled or non-recycled wet-process phosphoric acid.

3 cl, 10 tbl, 3 ex