| 摘要 |
<p>poor in F and highly soluble in citric acid is produced by calcination of a mixt. of (A) crude phosphate, (b) phosphoric acid, and (C) a cpd. forming Na2O at temps. 1200 degrees C in the presence of H2O vapour, in which (A) contains 2% wt. SiO2; (A), (B), and (C) are granulated together so that in the product the molar ratio will be 8:1:3, the granules are dried and calcined at 1350-1550 degrees C. The mixt. may contain 5-25% (C). (C) may be Na2CO3 and/or NaOH in soln. The product is used as a fertiliser and in animal feeds.</p> |
