Intensification of the reaction between Udaipur rock phosphate and sulphuric acid by means of ultrasound

This study investigates the solid-liquid reaction between Udaipur rock phosphate and varying concentrations of sulphuric acid, noting significant enhancement in reaction efficiency upon the application of high-intensity ultrasound (800 kHz and 80 W cm-‘). The results demonstrate that even coarser rock particles can be effectively decomposed, making it viable for industrial phosphatic fertilizer applications, a feat unattainable without ultrasound. The ultrasound effectively facilitates reactant diffusion onto solid rock particles while preventing the deposition of calcium sulphate on unreacted surfaces. An analysis of the decomposition curve at 80°C shows distinct maxima and minima influenced by the concentrations of H3O+, HSO4-, and SO4- ions throughout the reaction. Importantly, the presence of ultrasound minimizes the variability between these maxima and minima, consistently enhancing decomposition across all tested conditions. This research underlines the substantial potential of ultrasound technology in optimizing solid-liquid reaction processes, particularly in the fertilizer sector.