Keywords
washing
weakly acidic medium
harmful impurities
phosphate
fluoride
SEM
secondary raw material.
How to Cite
Abstract
This article examines the ecological and technological foundations of purifying phosphogypsum from harmful impurities. Phosphogypsum is a technogenic waste generated in large quantities during the production of wet-process phosphoric acid from phosphate raw materials. In addition to calcium sulphate dihydrate, it contains phosphates, fluorides, silicon, iron and aluminium compounds, soluble salts, and other impurities. These impurities limit the use of phosphogypsum in the production of construction materials, mineral fertilizers, and chemical products. In this study, the potential to improve the physicochemical and morphological properties of phosphogypsum samples was evaluated by first washing them with ordinary water, then with weakly acidic water, using a counter- current washing method. During the washing process, partial removal of soluble phosphate and fluoride ions, residual acids, and finely dispersed impurities was observed. SEM analysis revealed uneven layers and adhered impurities on the surface of unwashed phosphogypsum, whereas the washed sample exhibited relatively cleaner crystal surfaces. The results substantiate the necessity of a washing stage before using phosphogypsum as a secondary mineral raw material for subsequent chemical conversion, the production of ammonium sulfate and calcium carbonate, and the manufacture of construction materials.References
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Copyright (c) 2026 Shafoat Sattarovich Namazov, Ruzmat Radjabov, Jamshid Erkinovich Kholmurodov, Bekzod Nosirovich Karshiev, Jaloliddin Khasanovich Khudayberdiyev (Author)