Аңдатпа
This study investigates the formation of magnesium- and phosphorus-containing compounds suitable for use as fertilizers, based on the reaction of serpentinite waste with phosphoric acid. Serpentinite waste from the Zhitikara deposit was treated with phosphoric acid at different stoichiometric ratios. The reaction products were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and pH measurements. Phosphoric acid effectively decomposed the serpentinite structure, leading to the formation of hydrated magnesium phosphates. The phases Mg(H2PO4)2·2H2O and MgHPO4·3H2O were identified. At a 1:1 molar ratio of Mg2⁺ to H3PO4, the system reached a nearly neutral pH (~6.9) and produced a favorable phase composition for fertilizer use. Magnesium orthophosphate was not detected, likely due to its lower thermodynamic stability. Compared with other acids, phosphoric acid showed the highest efficiency in decomposing serpentinite. The resulting magnesium phosphate products possess high agrochemical potential, and the mild processing conditions support their practical application. This approach offers a sustainable and resource-efficient method for the utilization of serpentinite waste, contributing to waste valorization and the development of environmentally friendly fertilizers.