Reactivity of silicate–phosphate glasses in soil environment

Mechanism of chemical reactivity of glasses of the K2O–MgO–CaO–P2O5–SiO2 system, acting as slow release fertilizers in soil solutions was presented. The solubility of glasses in soil and soil simulated solutions were studied by chemical analysis (ICP-AES, EDS) and SEM observations.It has been found that the chemical reactivity of silicate–phosphate glasses in the soil environment comprises: gradual destruction of the internal structure of glass and washing out of the glass components, formation on the glass surface of a layer of metastable solid products and gradual washing out of the components of the surface layer.