Development of a dissolution model of a vitreous phosphorus-containing fertilizer concerning interdiffusion applied for calculation of fertilizer doses

The study was conducted during 2017 to 2019 at Saint Petersburg Mining University to create the dissolution model for the vitreous phosphorus-containing fertilizer AVA. The capillary electrophoresis study results confirm the significant influence of diffusion processes on the nature of kinetic dependencies of ion concentration profiles. For this reason, in the present work, along with the models of dissolution of vitreous phosphate fertilizers already considered by the authors, it was necessary to analyze the model of dissolution of spherical vitreous fertilizer granules taking into account interdiffusion. Previously unknown expressions for determining the time of complete dissolution of samples of glassy phosphate fertilizers were proposed. Equations have also been proposed for calculating the number of ions passing from the glass to the solution through 1 cm 2 of the surface of a spherical granule for any given time. Based on the above formulas, it is possible to calculate at a specific temperature the mass of nutrients that pass from the granules of vitreous phosphorous fertilizer to the solution for a certain time, which is very important for calculating the doses of fertilizers applied to various crops. Further, kinetic studies of the dissolution process of a vitreous phosphorus-containing fertilizer will make it possible to determine a relationship between the composition of the material and the dissolution rate, taking into account the temperature and acid-base characteristics of the soil.