Granulated fertilizer containing water soluble forms of nitrogen, magnesium and sulphur with ammonia and magnesium cations and sulphate and nitrate anions and method of preparation thereof

• Main Authors: KRALIK MILAN, LEHOCKY PETER, LENCSES LADISLAV, FERENCI MICHAL, POLAK ANTON, STEFANCOVA RADKA, KERDO PAVOL
• Format: Patent
• Language: English; Slovak
• Published: 07.04.2010
• Subjects: CHEMISTRY; FERTILISERS; FERTILISERS CHARACTERISED BY THEIR FORM; FERTILISERS PRODUCING CARBON DIOXIDE; INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; MANUFACTURE THEREOF; METALLURGY; MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENTSUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVINGA SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES,SOIL-CONDITIONERS, WETTING AGENTS; NITROGENOUS FERTILISERS

Granulated fertilizer containing water soluble forms of nitrogen, magnesium and sulphur contains 15 to 30 % by weight of nitrogen, 1 to 18 % by weight of sulphur, 2 to 10 % by weight of magnesium, expressed as magnesium oxid MgO, in the form of boussingaultite (NH4)2SO4.MgSO . 6H2O and binary salts of ammonium nitrate 2NH4NO3.(NH4)2SO4 and 3NH4NO3.(NH4)SO4, where the content of boussingaultite in fertilizer is 40 to 45 % by weight. It is prepared in such a manner, that magnesite is treated with concentrated nitrous acid, containing 30 to 80 % HNO3, at the temperature from 60 °C to 130 °C, the treatment results in reaction mixture containing magnesium nitrate, calcium nitrate, eventually, according to the content in magnesite, nitrates of iron, manganese or other metal elements, and the rest of indecomposed magnezite; subsequently, the reaction mixture is neutralized with alkaline agent to the pH value 3 to 7.5; the neutralized reaction mixture is then reacted with ammonium sulphate at the temperature 80 °C to 130 °C during 20 to 80 minutes, where the result of reaction is the pulp of boussingaultite (NH4)2SO4.MgSO . 6H2O containing 10 to 30 % by weight of water, and this pulp is mixed with recycled material from previous production in the ratio 1 : 2 to 1 : 10 and granulated; the process results in wet granulate, from which after removing free water the final product is obtained. Granulované hnojivo s obsahom vodorozpustných foriem dusíka, horčíka a síry obsahuje 15 až 30 % hmotn. dusíka, 1 až 18 % hmotn. síry, 2 až 10 % hmotn. horčíka, vyjadrené ako oxid horečnatý MgO, vo forme boussingaultitu - (NH4)2SO4.MgSO4.6H2O a podvojných solí dusičnanu amónneho - 2NH4NO3.(NH4)2SO4 a 3NH4NO3.(NH4)2SO4, pričom obsah boussingaultitu v hnojive je 40 až 45 % hmotn. Pripraví sa tak, že na magnezit sa pôsobí koncentrovanou kyselinou dusičnou s obsahom 30 až 80 % HNO3 pri teplote od 60 °C do 130 °C, za vzniku reakčnej zmesi obsahujúcej dusičnan horečnatý, dusičnan vápenatý, prípadne podľa obsahu v magnezite dusičnany železa, mangánu a ďalších kovových prvkov, a zvyšok nerozloženého magnezitu, nato sa reakčná zmes zneutralizuje alkalickým činidlom, na pH 3 až 7,5, zneutralizovaná reakčná zmes sa následne nechá reagovať so síranom amónnym pri teplote 80 až 130 °C počas 20 až 80 min. za vzniku brečky boussingaultitu (NH4)2SO4.MgSO4.6H2O s obsahom vody 10 až 30 % hmotn., ktorá sa zmieša s vysušeným recyklom z predchádzajúcej výroby v pomere 1 : 2 až 1 : 10 a granuluje sa za vzniku mokrého granulátu, z ktorého sa po odstránení voľnej vody vysušením získa finálny produkt.