A method for producing metal borohydride, Me(BH.sub.4).sub.n, from metal boron oxide, Me(BO.sub.2).sub.n, in which Me is a metal or a molecule that shows metal-like behaviour and can act as a metal, and n is an integer number that can be associated with the valence of the metal, wherein in a first fluidized bed step the metal boron oxide is provided in a first fluidized bed. The first fluidized bed is fluidized using a gas selected from at least one of nitrogen, N.sub.2, gas and a noble gas, optionally the noble gas being selected from at least one of helium, He; neon, Ne; argon, Ar; and xenon, Xe, under such circumstances, especially pressure and temperature, that oxygen atoms are removed from the metal boron oxide to provide metal boron, MeBn, particles, possibly ions. In a subsequent second fluidized bed step the metal boron particles are provided in a second fluidized bed that is fluidized using hydrogen, H.sub.2, gas under such circumstances that hydrogen chemically reacts with the metal boron particles to provide metal borohydride.

A method for producing metal borohydride, Me(BH.sub.4).sub.n, from metal boron oxide, Me(BO.sub.2).sub.n, in which Me is a metal or a molecule that shows metal-like behaviour and can act as a metal, and n is an integer number that can be associated with the valence of the metal, wherein in a first fluidized bed step the metal boron oxide is provided in a first fluidized bed. The first fluidized bed is fluidized using a gas selected from at least one of nitrogen, N.sub.2, gas and a noble gas, optionally the noble gas being selected from at least one of helium, He; neon, Ne; argon, Ar; and xenon, Xe, under such circumstances, especially pressure and temperature, that oxygen atoms are removed from the metal boron oxide to provide metal boron, MeBn, particles, possibly ions. In a subsequent second fluidized bed step the metal boron particles are provided in a second fluidized bed that is fluidized using hydrogen, H.sub.2, gas under such circumstances that hydrogen chemically reacts with the metal boron particles to provide metal borohydride.

Disclosed is a method for producing a metal borohydride and/or H.sub.2, including: A. producing a metal borohydride in a synthesis process, in which H.sub.2 is a reactant and the reaction further takes metal hydroxide and boron oxide or further takes metal boron oxide; B. producing H.sub.2 in a chemical reaction process, in which metal borohydride produced in step A and H.sub.2O are reactants, the amount of H.sub.2 produced in step B being larger than the amount of H.sub.2 required as a reactant in step A for the same amounts of metal borohydride as a reactant and a reaction product in steps B and A, respectively; and C. providing H.sub.2 produced in step C to step A, and repeating steps A, B and C. Part of the metal borohydride and/or H.sub.2 is withdrawn while leaving an amount of metal borohydride and H.sub.2, respectively, so as to allow repeating steps A-C.

Disclosed is a method for producing a metal borohydride and/or H.sub.2, including: A. producing a metal borohydride in a synthesis process, in which H.sub.2 is a reactant and the reaction further takes metal hydroxide and boron oxide or further takes metal boron oxide; B. producing H.sub.2 in a chemical reaction process, in which metal borohydride produced in step A and H.sub.2O are reactants, the amount of H.sub.2 produced in step B being larger than the amount of H.sub.2 required as a reactant in step A for the same amounts of metal borohydride as a reactant and a reaction product in steps B and A, respectively; and C. providing H.sub.2 produced in step C to step A, and repeating steps A, B and C. Part of the metal borohydride and/or H.sub.2 is withdrawn while leaving an amount of metal borohydride and H.sub.2, respectively, so as to allow repeating steps A-C.

A method for preparing lithium borohydride by means of room temperature solid phase ball milling, comprising the following steps: uniformly mixing a magnesium-containing reducing agent and a lithium metaborate-containing reducing material under a non-oxidizing atmosphere at room temperature, performing solid phase ball milling, isolating and purifying to obtain lithium borohydride. The method has the advantages of having a simple process, having a controllable and adjustable reaction procedure, having mild reaction conditions, energy consumption being low, costs being low, and output being high, while creating no pollution, being safe and cyclically using boron resources, having important practical significance.

A method for preparing lithium borohydride by means of room temperature solid phase ball milling, comprising the following steps: uniformly mixing a magnesium-containing reducing agent and a lithium metaborate-containing reducing material under a non-oxidizing atmosphere at room temperature, performing solid phase ball milling, isolating and purifying to obtain lithium borohydride. The method has the advantages of having a simple process, having a controllable and adjustable reaction procedure, having mild reaction conditions, energy consumption being low, costs being low, and output being high, while creating no pollution, being safe and cyclically using boron resources, having important practical significance.

In a hermetic vessel filled with hydrogen gas, a sodium borate and aluminum powder are reacted at not less than 400° C. and not more than 560° C. while performing stirring to produce sodium borohydride with the molar ratio of sodium contained in the sodium borate being larger than 0.5 relative to boron contained in the sodium borate.

A sodium borate, aluminum powder and fluoride powder are mixed together in a hermetic vessel filled with hydrogen gas, and the mixture is reacted at not less than 410° C. and not more than 560° C. to produce sodium borohydride.

A method for preparing lithium borohydride by means of room temperature solid phase ball milling, comprising the following steps: uniformly mixing a magnesium-containing reducing agent and a lithium metaborate-containing reducing material under a non-oxidizing atmosphere at room temperature, performing solid phase ball milling, isolating and purifying to obtain lithium borohydride. The method has the advantages of having a simple process, having a controllable and adjustable reaction procedure, having mild reaction conditions, energy consumption being low, costs being low, and output being high, while creating no pollution, being safe and cyclically using boron resources, having important practical significance.

A method for preparing lithium borohydride by means of room temperature solid phase ball milling, comprising the following steps: uniformly mixing a magnesium-containing reducing agent and a lithium metaborate-containing reducing material under a non-oxidizing atmosphere at room temperature, performing solid phase ball milling, isolating and purifying to obtain lithium borohydride. The method has the advantages of having a simple process, having a controllable and adjustable reaction procedure, having mild reaction conditions, energy consumption being low, costs being low, and output being high, while creating no pollution, being safe and cyclically using boron resources, having important practical significance.