Used as a flux in analytical chemistry for decomposing minerals and ores, especially in sample preparation for elemental analysis. Helps lower the melting point of samples during fusion processes, making it easier to dissolve refractory materials like oxides and silicates. Commonly used in gravimetric and spectroscopic analysis. Also employed in the production of potassium sulfate and other potassium salts. In industrial settings, it acts as an acid catalyst in certain chemical reactions and as a cleaning agent in metal treatment processes. Its acidic nature makes it useful for pH adjustment in specific non-aqueous or high-temperature systems.