Abstract: The invention relates to a method for extracting rare earth elements contained in permanent magnets, which includes the steps of thermal treatment of the permanent magnet, crushing at the end of the thermal treatment in order to obtain particles with a size smaller than 2 mm, treatment by agitation of the particles in a solution containing an organic acid, and separation of the liquid phase from the solid phase.

Abstract: The invention relates to a method for extracting rare earth elements contained in permanent magnets, which includes the steps of thermal treatment of the permanent magnet, crushing at the end of the thermal treatment in order to obtain particles with a size smaller than 2 mm, treatment by agitation of the particles in a solution containing an organic acid, and separation of the liquid phase from the solid phase.

Abstract: The invention relates to a method for extracting rare earth elements contained in permanent magnets, which includes the steps of thermal treatment of the permanent magnet, crushing at the end of the thermal treatment in order to obtain particles with a size smaller than 2 mm, treatment by agitation of the particles in a solution containing an organic acid, and separation of the liquid phase from the solid phase

Abstract: A method for separating the gaseous CO2 contained in a gas mixture, includes: the step of suspending in a liquid phase a solid absorbent capable of trapping the gaseous CO2; the step of dispersing the gas mixture into the liquid phase, the step being carried out at a temperature ranging from the liquid phase solidification temperature to the evaporation temperature, with the limits excluded, and under a pressure ranging from the atmospheric pressure to 10 bars, with the limits included.

Abstract: A method of separating/purifying a gas mixture (M), includes a step consisting in capturing at least one gas which can generate anionic species by dissolution in aqueous phase. The invention is characterised in that it also includes the following steps consisting in: suspending an absorbent product in the aforementioned aqueous phase, the absorbent product consisting of a lamellar double hydroxide or a mixed oxide which is believed to be amorphous and which originates from the moderate heat treatment of lamellar double hydroxides having an affinity for the above-mentioned gas; distributing the gas mixture (M) in the aqueous phase; and recovering the adsorbate from the absorbent product in suspension.

Abstract: A ceramic material based on Sialon, in particular on .beta.'-Sialon is obtained by reducing an aluminosilicate precursor by means of a gas phase comprising a mixture of hydrogen and nitrogen doped with a gaseous carbon compound. The gaseous carbon compound is a gas containing carbon in combined form, e.g. an alkane, and its concentration by volume in the gas is less than 3%. The method is particularly suitable for forming Sialon-based coatings on substrates that are solid or fibrous. For composite materials constituted by a fiber preform densified by means of a matrix, the method can be used to form an interphase coating on the fibers of the preform prior to densifying the preform, or the method can be used to form a matrix that is based on Sialon.