The paper summarizes the results of studies of the complexing properties of phosphoryl ketones with respect to actinides and lanthanides, which makes it possible to identify the most effective and selective ligand of the phosphoryl ketones class, namely 5-(diphenylphosphoryl)hexan-3-one. Using this ligand, the possibility of efficient extraction of rare earth metals, as well as uranium(VI) and thorium(IV) from phosphogypsumleaching solutions within a single stage technological extraction process was demonstrated and the efficiency of using 5-(diphenylphosphoryl)hexan-3-one as extractant with commercially available TBP and TOPO was performed.