| 摘要 |
<p>A process for digesting phosphate ore with HNO3 is claimed in which Ca(NO3)2 is crystd. from the digestion liquor by cooling, the crystals are sepd. from the mother liquor by centrifuging, and the sepd. crystals are washed with cold HNO3. The novel feature comprises filtering the mother liquor and wash liquor successively on a single filter so that the filter cake obtained from the mother liquor is washed with the wash liquor, which is then recycled to the digestion step. Filtering the wash liquor reduces the load on the cooling and crystn. sections (cf. NL.31032).</p> |
