| 摘要 |
<p>Particulate ferrophosphorus is partially oxidised to 600-750 degrees C for 1/4 to 2 hours is then again reduced to particles and heated at 800-900 degrees C for 1/2 to 5 hours to complete conversion of the phosphorus to phosphate. The prod. is mixed with an alkaline earth cpd. in an alkali-phosphorus mole ratio of 1:1 to 2:1 and with an alkali metal salt forming 3 to 35% by weight of the alkaline earth - phosphate mixt., the final mixt. being roasted at 700-1050 degrees C for >=45 minutes and then leaching with an aq. soln. to extract V. A V contg. ore may be mixed with the initially roasted for ferrophosphorus, while the mixt. prior to final roasting may be compacted with water. The alkaline earth material may be CaCO3, CaO, MgCO3, MgO, slags or ores, and the alkali metal salt may be NaCl, KCl, Na2CO3, or Na2SO4.</p> |
