Method for preparing borohydrides of potassium, rubidium, and cesium

Claim 1

IN A METHOD FOR PREPARING A BOROHYDRIDE OF AN ALKALI METAL SELECTED FROM THE GROUP CONSISTING OF POTASSIUM, RUBIDIUM AND CESIUM, THE STEPS WHICH CONSIST IN SELECTING A COMPOUND OF THE SELECTED ALKALI METAL OTHER THAN THE BOROHYDRIDE WHICH AS WELL AS THE CORRESPONDING SODIUM COMPOUND FORMS A SOLUTION WHEN MIXED WITH WATER, MIXING AT A TEMPERATURE OF ABOUT NORMAL ROOM TEMPERATURE A SUBSTANTIALLY SATURATED SOLUTION OF SAID SELECTED COMPOUND OF THE SELECTED ALKALI METAL IN WATER WITH A SUBSTANTIALLY SATURATED SOLUTION IN WATER OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF SODIUM BOROHYDRIDE AND A REACTION MIXTURE CONSISTING ESSENTIALLY OF SODIUM BOROHYDRIDE AND A SODIUM BORATE AND SODIUM FROM THE GROUP CONSISTING OF SODIUM BORATE AND SODIUM ALKOXIDE THEREBY PRECIPITATING THE BOROHYDRIDE OF THE SELECTED ALKALI METAL IN THE RESULTING REACTION LIQUOR, AND SEPARATING THE PRECIPITATED BOROHYDRIDE FROM SAID REACTION LIQUOR AT SUBSTANTIALLY NORMAL ROOM TEMPERATURE.