BEADS OF POLYCRYSTALLINE ALKALI-METAL OR ALKALINE-EARTH METAL FLUORIDE, THEIR PREPARATION AND THEIR USE

摘要

The present invention has the following objectives: polycrystalline alkali-metal or alkaline-earth metal (more particularly CaF2) fluorides, produced in an original form, namely in the form of beads; said beads having a diameter or equivalent diameter greater than or equal to 100 mu m, advantageously between 100 mu m and 2 cm and an apparent density greater than or equal to 60 %, advantageously at least 90 % of the theoretical density of said fluoride; a process for the preparation (the conditioning) of said fluorides; a process for the preparation of single crystals of the corresponding alkali-metal or alkaline-earth metal fluorides that uses polycrystalline fluorides in the aforementioned original form.