The investigation of the actinide and lanthanide distribution between a liquid metal and a molten fluoride salt shows a significant increase of the separation coefficient by using an aluminum-based pyrochemical system instead of a zinc-based system. The obtained values partly depend on the LiF/AlF3 ratio and can reach more than 30 000 when AlF3 is in excess with regard to the formation of the cryolite (Li3 AlF6). Furthermore, in the metal phase, the aluminum interacts with the lanthanides to a lesser extent than in other usual metallic solvents. This opens a new way to explore the feasibility of the separation of actinides and lanthanides in the field of nuclear fuel reprocessing.