Advanced Energy-Saving Technology of Granular Nitrate-Containing NPK-Fertilizers

Abstract

There was developed the technology of granular balanced nitrate-containing NPK-fertilizers 16-16-16 and 17-17-17. Key features of the proposed technology are: - Joint ammoniation of a mixture of nitric and phosphoric acids to a molar ratio of NH3:H3PO4 1.4÷1.5 and complete-ammoniation in Ammoniatior-Granulator drum to 1.65÷1.8. - Due to more efficient use of acid neutralization heat, the fluent slurry is obtained with low moisture content required for granulation. Ammoniation of a mixture of nitric and phosphoric acids at higher molar ratio makes it possible to exclude the possibility of acidification of ammonium nitrate, which causes the process of self-accelerating decomposition. The production of fertilizer grades with an increased molar ratio in the product have the following advantages: - higher degree of WPA neutralization to a molar ratio of NH3:H3PO4 of 1.65÷1.8 mol / mol allows to reduce the consumption of nitric acid and to exclude the stage of forced evaporation of nitrate slurry and the stage of ammonium nitrate melt preparation; - the cost of NPK-fertilizers with a lower content of ammonium nitrate is lower due to partial substitution of the nitrate nitrogen for ammonia nitrogen. - improvement of physical and chemical properties of the final product due to reduction of nitrate nitrogen content, - thermal stability of the obtained nitrate-containing NPK-fertilizers with an increased molar ratio in the product 1.65÷1.8; - flexibility to obtain a broad range of NPK-fertilizer grades.