[en] A process was developed for the pyrochemical recovery of plutonium from residues resulting from the PuF⁴ reduction process. The process involves crushing the CaF² slag and dissolving it at 800₀C in a CaCl² solvent. The plutonium, which exists either as finely divided metal or as incompletely reduced fluoride salt, is reduced to metal and/or allowed to coalesce as a massive button in the bottom of the reaction crucible. The recovery of plutonium in a 1-day cycle averaged 96%; all of the resulting residues were discardable