An Overview of Potassium Sulfate Production from Phosphogypsum by-Product

Abstract

Phosphogypsum (PG) is an acidic by-product that is generated during the manufacture of phosphoric acid using the sulfuric acid route. The management of PG poses a significant environmental and human health challenge worldwide due to its huge quantity and chemical composition. This review offers an extensive analysis of the existing literature related to the wet conversion of gypsum, specifically PG, using potassium chloride (KCl), potassium carbonate (K₂CO₃), and potassium hydroxide (KOH) to produce potassium sulfate (K₂SO₄). Furthermore, we discuss the factors that influence these conversions, enabling a comparative study to identify the optimal conditions for achieving complete PG conversion. The economic feasibility and environmental implications of these three PG conversions are also examined and discussed.

Keywords: Phosphogypsum; Potassium sulfate; Conversion; Potassium chloride; Potassium carbonate; Potassium hydroxide.