To obtain a pure sample of caesium, of mineral water had to be evaporated to yield of concentrated salt solution. The alkaline earth metals were precipitated either as sulfates or oxalates, leaving the alkali metal in the solution. After conversion to the nitrates and extraction with ethanol, a sodium-free mixture was obtained. From this mixture, the lithium was precipitated by ammonium carbonate. Potassium, rubidium, and caesium form insoluble salts with chloroplatinic acid, but these salts show a slight difference in solubility in hot water, and the less-soluble caesium and rubidium hexachloroplatinate () were obtained by fractional crystallization. After reduction of the hexachloroplatinate with hydrogen, caesium and rubidium were separated by the difference in solubility of their carbonates in alcohol. The process yielded of rubidium chloride and of caesium chloride from the initial 44,000 litres of mineral water.
To obtain a pure sample of caesium of mineral water had to be evaporated to yield of concentrated salt solution The alkaline earth metals were precipitated either as sulfates or oxalates leaving the alkali metal in the solution After conversion to the nitrates and extraction with ethanol a sodium-free mixture was obtained From this mixture the lithium was precipitated by ammonium carbonate Potassium rubidium and caesium form insoluble salts with chloroplatinic acid but these salts show a slight difference in solubility in hot water and the less-soluble caesium and rubidium hexachloroplatinate () were obtained by fractional crystallization After reduction of the hexachloroplatinate with hydrogen caesium and rubidium were separated by the difference in solubility of their carbonates in alcohol The process yielded of rubidium chloride and of caesium chloride from the initial 44000 litres of mineral water