Abstract: An aqueous solution of hydrogen peroxide is produced by direct synthesis from hydrogen and oxygen in the presence of a heterogeneous catalyst. According to the invention, a gas mixture comprising H.sub.2 and O.sub.2, essentially saturated or supersaturated with water (=containing fog) is fed into a reactor containing the catalyst. The volume ratio of the gas mixture fed in (standard liters per hour) to liquid removed (liters per hour) is adjusted to a value equal to or greater than 15,000, especially 20,000 to 50,000, and the gas mixture leaving the reactor is recycled after replenishment with H.sub.2, O.sub.2, and H.sub.2 O vapor. Solutions with high H.sub.2 O.sub.2 concentration can be obtained according to the invention without additional concentration.

Abstract: A process for the direct preparation of alkali metal cyanide and alkaline earth metal cyanide granules from an HCN-containing gas and an aqueous solution or suspension of an alkali metal or alkaline earth metal hydroxide. The reaction is performed in a reactor for fluidized bed spray granulation, wherein a solution or suspension of the hydroxide is sprayed onto seed granules of the cyanide being prepared and at the same time a hydrogen cyanide-containing gas is supplied to the reactor and water is evaporated by means of a fluidizing gas. The preferred fluidizing gas is steam. The reaction gases from a BMA or Andrussow process may be quenched with water and the gas mixture used as fluidizing gas. By using a CO.sub.2 -free HCN-containing gas, alkali metal cyanide granules with advantageous properties, including a combined concentration of alkali metal carbonate and alkali metal formate of less then 0.4 wt. %, are obtainable.