Abstract
The reactions of silica minerals at high temperature Bayer digestion conditions have been investigated using an in situ X-ray diffraction technique. Rapid precipitation of sodalite was observed following the addition of kaolin or quartz to Bayer liquor at 250 °C. The addition of calcium with kaolin/quartz resulted in the formation of calcium cancrinite. A reduction in the rate of both sodalite and calcium cancrinite formation was observed on decreasing the temperature in the range 180-250 °C. Seeding with sodalite/calcium cancrinite solids did not noticeably influence the reaction of quartz at 250 °C, but a slight increase in the formation of calcium cancrinite in the presence of calcium cancrinite seed was observed at 220 °C. The direct transformation of sodalite to calcium cancrinite was also investigated in the range 200-250 °C. The reaction proceeds quickly in the presence of calcium and hydrogarnet and is unaffected by the presence of titanium.
| Original language | English |
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| Pages (from-to) | 4499-4505 |
| Number of pages | 7 |
| Journal | Crystal Growth and Design |
| Volume | 8 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2008 |