PHOSPHATE FERTILIZERS RICH IN SULFUR AND IN TRACE ELEMENTS FOR AGRICULTURAL AND INDUSTRIAL USE, THEIR MANUFACTURING PROCESS AND THEIR USES

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.