Features of Phase Formation during “Dry” Neutralization in the System Na[2]CO[3]–H[2]O–H[x]An

Abstract

It was found that during the “dry” neutralization of mono- (acetic) and polybasic (orthophosphoric, citric, sulfuric) acids (HxAn) in the Na[2]CO[3]–H[2]O–HxAn system with a molar ratio Na[2]CO[3]/H[x]An = 1.5–10.5 at the interface, sodium sesquicarbonate (Na[2]CO[3]·NaHCO[3]·2H[2]O) crystallizes as a result of decomposition of Na[2]CO[3], dissolution of the resulting CO[2] in the surface liquid layer and its interaction with CO[3]{2–} anions with the formation of an equimolar amount of HCO[3] – anions. The hydrated salts formed during the process (phosphates, acetates, citrates, and sodium sulfates) play the role of binders during the aggregation of particles into granules of a 0.106–1.00 mm size.