Thorium tetrafluoride

Our information on AHf(PuF4,c) is based on high temperature reactions (600-900 K) already assessed in 1966 by Rand (21) and on extrapolation of uranium and thorium tetrafluoride data. Thus we have... 

Hydrogen fluoride is not the only reagent that can be used for the high-temperature dry-way preparation of uranium tetrafluoride. Cacciari et al. (14) have described the preparation of uranium and thorium tetrafluorides by the reaction at 400° of uranium trioxide or thorium dioxide with fluori-nated hydrocarbons ... 

TaCI5[g] TANTALUM PENTACHLORIDE (GAS) 1599 ThF4 THORIUM TETRAFLUORIDE 1649... 

TaF5 TANTALUM PENTAFLUORIDE 1599 ThF4[g] THORIUM TETRAFLUORIDE (GAS) 1650... 

EYE] D Eye, R. W. M., The thorium dioxide-thorium tetrafluoride system,... 

GAG/MAS2] Gagarinskii, Y. V., Mashirev, V. P., Ciystalhne hydrates of thorium tetrafluoride, Russ. J. Inorg. Chem., 4, (1959), 562-565. Cited on pages 225, 455. 

Darnell, A. J., The free energy, heat, and entropy of formation of thorium tetrafluoride. Atomics International, Report NAA-SR-4924, (1960). Cited on pages 200, 201, 463, 601. 

NAG/BHU2] Nagarajan, K., Bhupathy, M., Prasad, R., Singh, Z., Venugopal, V., Sood, D. D., Vaporization behaviour of thorium tetrafluoride, Ther-mochim. Acta, 36, (1980), 85-89. Cited on pages 200, 203, 569, 570. 

Dyke, J. M., Josland, G. D., Morris, A., Tucker, P. M., Tyler, J. W., Study of the valence-electronic stracture of uranium and thorium tetrafluorides and tetrachlorides in the gas phase and in the solid... 

Fig. S.8. Stirred bed plant for the production of thorium tetrafluoride (From F. L. Cnthbert, Thorium Production Technology, 1958, Addison-Weslq, ...

Typical impurity analyses of thorium oxide feed and thorium tetrafluoride product are shown in Table 4. 

Thorium tetrafluoride is produced fairly readily by reacting the pure oxide with anhydrous hydrogen fluoride by a typical dryway technique. A simple tunnel furnace made of inconel may be used, with inconel trays. A 98 per cent yield can be obtained in about 10 hr at 5S0°C, using an excess of the fluorinating agent. 

In a comparable American process, operated on a semi-production scale by the U.S.A.E.C. Ames Laboratory, zinc chloride is found to be the most satisfactory booster, as a 10 per cent admixture with the thorium tetra-fluoride. A 25 per cent excess of calcium is used over the stoichiometric requirements of the thorium tetrafluoride. 

Fig. 6.8. Typical thorium billet from thorium tetrafluoride (Audsely, A.. Lind, R. and England, P. G. Ref. 16). 

Conversion to thorium tetrafluoride. This conversion is performed at 566 C by a hydro-fluorination exothermic reaction achieved in a series of screw-fed horizontal reactors made of AlSl 309Nb stainless steel with a screw of lllium R or Inconel in which solid and gases flow countercurrently. During the exothermic reaction the conversion of the thorium dioxide into thorium tetrafluoride occurs with the recovery of hydrofluoric acid as a commercial byproduct according to the following scheme ... 

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