| 摘要 |
<p>PURPOSE:To recover uranium inexpensively and simply from wet process phosphoric acid in a high yield by adding an alkaline earth metallic compound to the phosphoric acid, further adding gypsum dihydrate, and capturing uranium in a hemihydration stage. CONSTITUTION:An alkaline earth metallic compound is added to wet process phosphoric acid contg. uranium obtd. by treating phosphate ore so as to adjust the concn. of alkaline earth metallic ions in the phosphoric acid to >=0.1wt%. After further adding gypsum dihydrate, the phosphoric acid is heated and held at above the transition temp. of hemihydrate gypsum to cause transition from the gypsum dihydrate to hemihydrate gypsum and to capture uranium. All of the formed hemihydrate gypsum is separated from the phosphoric acid, dispersed in water, and hydrated to cause transition to gypsum dihydrate and to shift the uranium to the liq. phase. The mother liquor after the hydration is separated, and by adding a precipitant, the uranium is recovered as an insoluble precipitate. Said wet process phosphoric acid may be used after defluorination. The preferred alkaline earth metallic ions are Ca or Mg ions. Gypsum dihydrate separated after transition can be recycled.</p> |
