METHOD FOR PRODUCING COMPLEX PHOSPHORUS-COMPRISING GRANULATED FERTILIZERS Russian patent published in 2023 - IPC C05B11/08 C05G5/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing granular complex NPKS/NPK/NPS/NP fertilizers within one unit. The method involves neutralizing phosphoric and sulfuric acids with ammonia in two stages: first in a capacitive neutralizer, then in tubular reactors. The suspension obtained at the second stage of neutralization is sprayed through nozzles into the ammonizer-granulator, where it is mixed with recycle, potassium chloride, crystalline ammonium sulphate, urea and other components of complex fertilizers, depending on the grade produced, and is further neutralized with liquid ammonia to obtain a granular product. The ratio of liquid and solid phases at the granulation stage is adjusted in the range of 1:2.3-4.5. The resulting product is then sent for drying in a drying drum, followed by sifting, cooling and surface conditioning of the commercial fraction. Part of the suspension after the first stage of neutralization can be fed directly to the ammoniator-granulator. Part of the flow of phosphoric and sulfuric acids can be sent for neutralization with ammonia in one stage in a tubular reactor installed in the inlet part of the drying drum.

EFFECT: ability to produce a wide range of granular complex NPKS/NPK/NPS/NP fertilizers with a commercial fraction content of at least 90% without compromising quality characteristics and reducing productivity, while due to the efficient use of heat from chemical reactions, the specific consumption of natural gas and emission of greenhouse gases are reduced and part of the phosphoric acid can be processed in undiluted form.

3 cl, 1 dwg