The structure of carbamide granules, which are encapsulated with an organic shell, is studied in this article. A schematic diagram of an experimental setup for producing organo-mineral fertilizers with a nanoporous shell is proposed. The use of a disk (pan) granulator to encapsulate mineral fertilizers with an organic nanoporous shell has been substantiated. The features of the structure of nanopores that allow to obtain an effective dissolution process of the shell and granule in the soil are presented. Nanoporous structure of the shell is uniform over the entire surface of the shell and occupies from 65 to 75% for different samples. The thickness of the shell in the different parts of the granule is uneven, which requires additional study and correction of the technological parameters of the process. The morphology of the shell's porous structure: rectilinear and curved nanopores, the depth of which ranges from 0.1 to 0.2 of the shell thickness. The pores in shell create a developed structure throughout the entire thickness of the shell, connecting with each other at different depths (thicknesses) of the shell. On the shell surface there is a certain amount of "mechanical" pores, which probably formed during the drying of the sample; the presence of such pores leads to the need to revise the thermodynamic characteristics of the drying process. The elemental composition of the granule core and shell has been studied in order to predict the process of penetration of shell elements into the core within the chosen encapsulation technology. The obtained results allow to improve the technology of obtaining encapsulated fertilizers in pan granulators. Based on the obtained data, it seems possible to improve the algorithm for constructive calculation of the pan granulator.

No abstract

No abstract