| 摘要 |
A phosphated fertiliser (I) contains sulphur and trace elements and has a typical compsn. (by wt.) of: 5-12% P2O5 total; 3- 8% P2O5 soluble in water and neutral ammonium citrate (in the form of (PO4H2)2Ca and PO4HCa); 3-10% Ca; 25-40% SO3 (in the form of sulphates); 10-17% Fe(II); 2-5% Fe(III); 0.5-2% Mn; 0.02-0.1% Zn; and 3-5% moisture. Also claimed is a process for mfr. of (I) comprising: (a) intimately mixing the residual material obtd. from the prodn. of TiO2 via sulphate intermediate, and phosphorite; (b) forming a pile; (c) leaving for 24hrs. then remixing; (d) re-mixing over several consecutive days; and (e) leaving the pile for sufficient time for the free H2SO4 from the residual material to react with the phosphorite.
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