Influence of Foreign Salts and Antiscalants on Calcium Carbonate Crystallization

For more than a century, crystallization has remained chief research topic. One of the most undesirable phenomena is formation calcium carbonate scale in drinking and industrial water systems. In this work, influence chemical additives on CaCO3 formation—in either nucleation, crystal growth, or inhibition processes—is investigated by using CO2-degasification method. Chemical are foreign salts (MgCl2, Na2SO4 MgSO4) to calco-carbonic system antiscalants (sodium polyacrylate ‘RPI’ sodium-tripolyphosphate ‘STPP’). The results show that affects both kinetics microstructure. Sulfate magnesium ions, added separately at constant ionic strength, nucleation step growth formed crystallites. Added simultaneously, their effect was accentuated CaCO3. Furthermore, RPI STPP affect process greatly delaying precipitation time largely increasing supersaturation coefficient. It also shown with prefers heterogeneous homogeneous one. X-ray diffraction patterns promote new polymorph as aragonite, addition initial polymorphs calcite vaterite.