Abstract: The invention relates to a process for the production of pure lithium oxide and its use, wherein lithium carbonate is reacted with finely divided, elemental carbon in powder form in the temperature range between 600 and 1200° C., wherein the two reactants are intensively premixed prior to the thermolysis process so that the bulk density of the mixture is reduced by at least 5%, preferably by at least 15%.

Abstract: The disclosed subject matter relates to a method for obtaining cesium from aqueous solutions.

Abstract: The invention relates to a method for obtaining caesium from aqueous starting solutions having caesium contents in the range of 50 ppm to 5000 ppm, in which method the caesium ions in the aqueous solution are, in a first step, precipitated as a double salt having divalent cations with the aid of an at least 1.1-times overstoichiometric amount of solutions containing prussiate of potash, in a pH range of 2 to 12 and a temperature range of 10 to 80° C., the divalent cations either already being present in the starting solutions in an amount at least equimolar to the caesium content or being added as a water-soluble salt, and, in a second step, converted back into a water-soluble form by thermal decomposition and, in a third step, separated from the insoluble residues.