A bone recuperating drilling device includes a trephine in the form of a tube designed to be driven in rotation, open at both ends and provided with teeth on the periphery of its front opening. The compressor also includes a slide vane mechanism that projects the second vanes into and draws in the second vanes from the diffuser path via the slits of the hub side wall part plate according to a load of the compressor. The inventive process comprises mixing such molecular sieve with a salt, either directly or as a slurry; and then heating the resulting mixture to remove water, organics and adsorbed species.