[en] For the preparation of uranium tetrafluoride wet procedures have been tried, in which hexavalent uranium is reduced to the tetravalent state, followed by the precipitation of the tetrafluoride. The characteristics of the fluoride prepared, which play a major role in the metal production processes, vary remarkably with the procedure of preparation. The photolytic refining-reduction method applied to precleaned phosphatic yellow cake has been extended to uranium tetrafluoride preparation. The effect of precipitation and washing of the product on its texture and density was examined and the Debyegrams were recorded. Nuclear purity uranium tetrafluoride has been prepared from photolytically reduced sulfate process liquor. Products of various tap density, texture and composition are obtained under different precipitation conditions. (P.J.)