METHOD OF OBTAINING COMPLEX PROLONGED FERTILISER Russian patent published in 2008 - IPC C05G3/04 C05D9/00 

FIELD: chemistry, agriculture.

SUBSTANCE: method of obtaining complex fertiliser of prolonged action on the basis of adsorption additive - tripoli, includes 5 stages. On the first stage tripoli is mixed with solution K₃[Al(OH)₆], obtained suspension is exposed in autoclave during 4 hours at pressure 5 atm and temperature 150°C, obtaining complex adsorbent. Mixture is washed with water in ratio mixture: water equal 1:3 and aboiled, obtained suspension is neutralised with hot phosphoric acid with concentration 30.7 wt % continuously mixing until solution with pH = 7.0 is obtained, suspension is dried to 1% humidity. On the second stage peat is processed with 30% solution of KOH while boiling during 0.5 hour with output of biologically active humic fraction. On the third stage nitrating mixture, consisting of P₂O₅ and HNO₃ in ratio 1:2 is obtained, it is combined with peat in ratio 1:1 mixing thoroughly and subjected to cooling during 0.5 hour in crystalliser with ice obtaining organic nitrogen-containing fraction of fertiliser. On the fourth stage biologically active humic and organic nitrogen-containing fraction of fertilizer are mixed, mixture is neutralised with 25% solution of ammonium, until solution with pH=7.0 is obtained, and dried. On the fifth stage complex adsorbent and mixture of organic and humic fractions are combined in ratio 1:2.7, crushed, and fertilizer, which contains in its composition the following elements: wt %: nitrogen N-21.96; phosphoric anhydride P₂O₅ 15.73; potassium oxide K₂O 11.20; silicon oxide SiO₂ 12.54; aluminium oxide Al₂O₃ 1.65; calcium oxide CaO 1.92; magnesium oxide MgO 0.30; iron oxide Fe₂O₃ 0.96; manganese oxide MnO₂ 0.14; peat and organic substances 33.6, is obtained.

EFFECT: reduction of obtained complex fertiliser cost and enhancing efficiency of prolonged impact of complex fertiliser on soil fertility.

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