Hafnium phosphate

In view of Thompson s results on the carrying of Pu+I by bismuth phosphate, Cunningham and Werner made an immediate test today to see whether it is carried at a ratio of Bi+3 Pu+1 of about 100 1. Their results indicate that under conditions similar to those of Thompson s experiment, the Pu+I> is carried to the extent of 98%. This was fast work and illustrates the pace at which our group is now working. They also made a test of the carrying of Pu+I> by hafnium phosphate at a ratio of Hf Pu of 100 1 and they find that about 90% of the Pu is carried. 

Hafnium chloride, 4 121 Hafnium phosphate, precipitation of, with zirconium phosphate, 3 71... 

The reagents (2) and (3) are added simultaneously by means of an atomizer arrangement (Fig. 15) into the hot 2 N sulfuric acid reaction medium. To obtain a satisfactory precipitate the reagents must be added at a rate not to exceed about 1 1. per hour. Care must be taken to add both reagents at an equivalent rate. The rate of flow is checked by means of a drop counter inserted below the stopcock of the separatory funnel, D. Since the rate of evaporation of the solution at 75° almost equals the rate of addition of the reagents, a constant volume of solution is maintained with some increase in the acid concentration. Inasmuch as zirconium and hafnium phosphates are among the most insoluble phosphates known, one complete precipitation serves to remove most of the impurities associated with the zirconium and hafnium. The precipitated phosphates are separated from the mother liquor by filtration. 

In order to proceed with the fractionation, the zirconium hafnium phosphates must be converted into acid-soluble compounds. Digestion of the moist phosphates with a mixture of sodium hydroxide and sodium peroxide yields a dense white peroxy compound, which can be washed free from the soluble phosphates, and which is soluble in acid with the evolution of oxygen. This reaction is utilized in the following procedure, except that 30 per cent hydrogen peroxide has been substituted for the sodium peroxide. 

Cyanamide, synthesis 9 Dicyanodiamide, synthesis 10 Barium thiocyanate, synthesis 5 Potassium ootacyanomolybdate (IV) 2-hydrate, synthesis 43 Zirconium hafnium phosphates, synthesis IOC... 

By contrast the introduction of trivalent cations, such as indium, into lithium hafnium phosphate gives only a modest increase in the conductivity of the sample. The room temperature conductivity of Lii 2Hfi.gIno.2(P04)3 is 10 S cm and this material is only marginally more conducting that the indium-free composition LiHf2(P04)3. Both materials shows a similar temperature-independent activation energy for conduction of ca 0.44 This modest enhancement in room tem-... 

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