| abstract |
The invention relates to a method for preparing alkali borohydride, in particular to a method for preparing sodium borohydride by a chemical mechanical mechanics method and solving the problems of environmental pollution, severe operation condition and the like during the preparation process of the sodium borohdride in the prior art. The method takes magnesium hydride as a hydrogen source, takes borax as a boron source and prepares the sodium borohydride by combining mechanical grinding with chemical reaction. In the hydrogen atmosphere, under a certain temperature and pressure, the magnesium powder is mechanically grinded and generates hydrogenation reaction with the hydrogen, thus preparing magnesium hydride; subsequently, the borax, sodium carbonate and magnesium hydride are arranged in a ball mill with a certain proportion; certain hydrogen pressure, ball material ratio and grinding time are kept, thus obtaining the sodium borohydride. The purity of the sodium borohydride prepared by the method can achieve more than 97%. The chemical mechanical mechanics method is adopted to prepare the sodium borohydride, and compared with the currently general Schlesinger method and Baeyer method, the method has the advantages of low raw material cost, simple, convenient and safe process, no pollution and the like. |