Patent GB-468697-A (GB)
Title: A process for simultaneously obtaining peroxides of alkali or earth alkali metals and valuable compounds of said metals
IPC: C01B15/023
Filed: 1936-01-07
Abstract: In the production of alkali or alkaline earth metal peroxides by preparing a non-acid solution of at least one organic compound which contains in its molecule at least two hydrogen atoms which can be eliminated by oxidation, by reducing a solution of that substance into which the same is converted by oxidation, by means of an alkali or alkaline earth metal amalgam and a substance, e.g. alcohol or water, which gives off hydrogen under the action of the amalgam, and oxidizing the reduced solution by means of oxygen or air, the oxidation is conducted under such conditions, particularly with regard to the amount of water and/or alkali or alkaline earth, that only part of the reducing metal in the solution is bound as peroxide, the peroxide formed being separated and the other part of the reducing metal being removed at any stage of the process in the form of the compound formed in the reduction step, e.g. alcoholate.  The use of sodium and barium amalgams is referred to.  In the reduction step, e.g. alcoholate. The use of sodium and barium amalgams is referred to.  In the reduction step, the liquid amalgam and the solution may flow down a slightly inclined tube, if desired, wound into a vertical spiral.  Instead of a single tube, a plurality of adjacent tubes or inclined surfaces, preferably provided with longitudinal channels, may be used.  Suitable organic compounds for the process include hydrozo-benzene, anthrahydroquinone, methyl-, ethyl-, propyl-, isopropyl-, chlor-, and hydroxy-anthrahydroquinones, phenanthrene-, chrysene-, and retenehydroquinones, the hydrogenation products of the said hydroquinones, e.g. tetrahydroanthrahydroquinones, and indigo-white and its substitution products.ALSO:In the production of alkali or alkaline earth metal peroxides by preparing a non-acid solution of at least one organic compound which contains in its molecule at least two hydrogen atoms which can be eliminated by oxidation, by reducing a solution of that substance into which the same is converted by oxidation, by means of an alkali or alkaline earth metal amalgam and a substance, e.g. alcohol or water, which gives off hydrogen under the action of the amalgam, and oxidizing the reduced solution by means of oxygen or air, the oxidation is conducted under such conditions, particularly with regard to the amount of water and/or of alkali or alkaline earth, that only a part of the reducing metal in the solution is bound as peroxide, the peroxide formed being separated and the other part of the reducing metal being removed at any stage of the process in the form of the compound formed in the reduction step, e.g. hydroxide or alcoholate.  The use of sodium or barium amalgams is referred to.  Suitable organic compounds include hydrazobenzene, anthrahydroquinone, methyl-, ethyl-, propyl-, isopropyl-, chlor- and hydroxy-anthrahydroquinones phenanthrene-, chrysene- and retenehydroquinones, the hydrogenation products of these compounds, e.g. tetra hydroanthrahydroquinones, indigo white and its substitution products and the corresponding quinhydrone-like compounds.  The conditions may be arranged so that during the reduction step saturation is reached and excess alkali separates in the solid form, e.g. as alcoholate or hydroxide.  The use of solvent mixtures, e.g. benzenealcohol, promotes such separation. Alternatively, a part of the alkali dissolved or suspended in the reduced organic solution may be washed out by means of a solvent for this alkali which is only slightly miscible with the reduced solution, preferably water or aqueous caustic alkali.  The alkali, e.g. sodium hydroxide, so washed out may be converted into an alkali salt by the addition of an acid, e.g. nitric or phosphoric acid, to the washing liquid.  The washing liquid may be circulated through the organic solution, preferably through the part of the apparatus in which solid alkali will settle.  In the reduction step, the liquid amalgam and the solution may flow down a slightly inclined tube, if desired, wound into a vertical spiral.  Instead of a single tube, a plurality of adjacent tubes or inclined surfaces, preferably provided with longitudinal channels, may be used.  A mixture of tetrahydronaphthalene and alcohol may be used as the solvent in which the process is carried out.  If oxygen is employed in the oxidation step, the formation of explosive mixtures may be prevented by maintaining a sufficient amount of an inert gas in the oxidation apparatus.