STUDY OF PHOSPHORIC ACID PURIFICATION DURING EXTRACTION AND ITS APPLICATION IN THE PRODUCTION OF HIGH-QUALITY NITROGEN–PHOSPHORUS FERTILIZERS STUDY OF PHOSPHORIC ACID PURIFICATION DURING EXTRACTION AND ITS APPLICATION IN THE PRODUCTION OF HIGH-QUALITY NIT

Аннотация

Objective: The purpose of this study is to investigate the purification of phosphoric acid derived from Central Kyzylkum phosphates using fluoride and sulfate additives during the extraction process. The work focuses on the removal of impurities such as iron, aluminum, calcium, magnesium, sulfate, and fluorine during the ammonium phosphate acid extraction stage, as well as the development of environmentally friendly, fully water-soluble ammonium phosphate fertilizers.

Methods: The research employed chemical and physicochemical techniques, including photocolorimetry, pH measurement, electron microscopy, along with statistical analysis of experimental results.

Results: Optimizing the phosphoric acid extraction process by simultaneous elimination of fluorine and sulfate impurities enabled effective removal of iron, aluminum, calcium, magnesium, fluorine, and other contaminants. The final product exhibited a high content of the main nutrient, P₂O₅.

Conclusion: The study demonstrates that co-treatment with calcium carbonate or washed calcined phosphate concentrate (WСPC) during extraction sludge processing allows simultaneous fluorine removal and desulfurization of wet-process phosphoric acid (WPPA) from Central Kyzylkum phosphates. Partial purification of phosphoric acid during extraction, followed by complete purification via ammoniation, produces high-quality, fully water-soluble ammonium phosphates. These nitrogen-phosphorus fertilizers are suitable for drip irrigation

systems and hydroponic cultivation