Extraction of rare earth elements with deep eutectic solvents

It relates to process for the extraction of rare earth elements from a starting product containing them in metal or alloy form which comprises: a) contacting the starting product containing rare earth elements in metal or alloy form with a deep eutectic solvent that consists of a mixture of a hydrogen bond acceptor (HBA) compound (A) selected from a salt of the formula Cat + X - (I), betaine or a salt thereof, and carnitine or a salt thereof; and a hydrogen bond donor (HBD) compound (B) in a molar ratio of (A) to (B) from 1:10 to 10:1, wherein the deep eutectic solvent is capable of extracting at least 50% w/w of one or more rare earth elements contained in the starting solid product in less than 5 hours, and b) separating the solvent containing the rare earth elements in dissolution from the undissolved solid.