摘要 |
<p>A process for making an industrially usable gypsum from fluoroanhydrite in which fluoroanhydrite is contacted with a fluid reaction medium slurry containing soluble sulfate ions and a substantial proportion of small gypsum seed crystals to rapidly hydrate a large proportion of the fluoroanhydrite to a coarser, substantially pure gypsum. The slurry is clarified to separate coarse purified gypsum reaction product, and the reaction medium reconstituted and recycled containing gypsum crystals less than the desired reaction product size and constituting about 50-90% of the total solids of the reconstituted fluid reaction medium.</p> |