PRODUCTION OF ORGANO-MINERAL FERTILIZING AMELIORANTS BASED ON PHOSPHOGYPSUM, CENTRAL KYZYLKUM PHOSPHORITES AND BIOHUMUS

Phosphogypsum, a large-scale industrial by-product generated during phosphoric acid production, poses significant environmental challenges due to its accumulation and potential ecological impact. This study investigates the utilization of phosphogypsum as a raw material for producing fertilizing ameliorants in combination with Central Kyzylkum phosphorites and biohumus. Composite mixtures were prepared and granulated using a 30% ammonium sulfate solution as a binding agent. The chemical composition, phase structure (XRD), and microstructure (SEM–EDS) of the obtained materials were analyzed. The results demonstrate the formation of calcium phosphate and sulfate phases, including CaHPO4·2H2O, β-Ca3(PO4)2, and CaSO4·2H2O, which contribute to both fast- and slow-release nutrient properties. The addition of biohumus improved the biological activity and structural properties of the materials. The optimal composition (phosphogypsum : phosphorite : biohumus = 1 : 1 : 0.5) showed enhanced agronomic characteristics, including improved available phosphorus content and granule strength.