METHOD OF COLORING COMPLEX GRANULAR FERTILIZER Russian patent published in 2019 - IPC C05G3/00 C05G1/00 

FIELD: agriculture.

SUBSTANCE: method of coloring complex granular NPK-fertilizers involves introduction of pigment together with potassium chloride into nitrophosphate melt, mixing and subsequent granulation, wherein iron azure is used as pigment, which is pre-dispersed prior to introduction into melt by dry grinding with potassium chloride, wherein iron azure consumption is maintained at least 0.1 % of fertilizer weight, preferably in range of 0.1–0.2 %.

EFFECT: invention enables to obtain a complex granular NPK-fertilizer with stable distinctive blue color and shades, which does not have contact granules.

1 cl, 1 tbl, 11 ex