Potassium hexaniobate

In our first approach, a nonradioactive, representative fission-product mixture was prepared, consisting of equal masses of the desired elements. An ammonium hydroxide solution was used to dissolve molybdenum trioxide, M0O3 this solution was added to an aqueous solution containing the nitrates of cerium, palladium, and rhodium. The resulting mixture was calcined at 500°C for 17 hours, then at 550°C for an additional seven hours. The solids from the calcination were powdered and added to a blended mixture consisting of the oxides of antimony, ruthenium, samarium, strontium, yttrium, and zirconium. Cesium was then added as cesium iodide niobium was added as potassium hexaniobate,... 

The individual elements produced various results. Additions of antimony oxide, tin(ll) oxide, and samarium oxide gave no evidence of reactions with the nitrate melt or solubility. The addition of zirconyl nitrate resulted in the evolution of nitrogen dioxide from the melt and the formation of a white insoluble precipitate. Addition of palladium nitrate to the melt produced a black melt and black insoluble solids. Dissolution of the cooled and solidified salt cake with distilled water indicated that a palladium mirror had formed at the meniscus of the melt. Niobium was added as potassium hexaniobate, KgNb Oj I6H2O. 

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