MAGNESIUM-PHOSPHATE COMPOUND FERTILISER AND PRODUCTION METHOD THEREOF Russian patent published in 2011 - IPC C05D5/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing compound mineral fertilisers and can be used in agriculture to increase yield. The method involves treatment of finely ground magnesium-containing material in form of serpentinite-containing industrial wastes with a 80-96% sulphuric acid solution heated to 40±0.5°C, while stirring and the ratio of the sulphuric acid to magnesium-containing material equal to 1.0:1.05-1.5 until complete decomposition of the magnesium-containing material. The decomposition product is then thoroughly mixed with ammophos or elementary superphosphate, or precipitate, or ammophoska in ratio of 1.4-2.4:1.0. The obtained mixture is neutralised to pH 8.0 and if necessary, the end product is granulated. The obtained magnesium phosphate fertiliser contains the following, wt %: P₂O₅ 12.0-27.5; P₂O₅ (r.f) 10.0-21.5; MgO - 16.1-32.0; SO₃ -16.2-36.2; SiO₂ - 8.0-13.9; N₂ - 0-8.8; CaO - 0-19.4; K₂O - 0-10.5; Pe₂O₃ - 0.1-1.2; H₂O - 7.8-14.9.

EFFECT: invention enables to obtain compound magnesium phosphate fertiliser through a wasteless, dry, energy-saving method, widens the raw material base and improved ecology owing to use of industrial wastes.

2 cl, 1 tbl, 11 ex