Synergistic effects of magnesium and EDTA on polymorphism and morphology of CaCO3 and its influence on scale

• Published in: Journal of crystal growth Vol. 564; p. 126108
• Main Authors: Nirmala Devi, M., Sanjiv Raj, K., Subramanian, V.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.06.2021; Elsevier BV
• Subjects: CaCO3; Calcium carbonate; Crystal Growth; Crystallization; EDTA; Ethylenediaminetetraacetic acids; Magnesium; Morphology; Polymorphism; Scale formation; Scale inhibition; Synergistic effect; CaCO3; EDTA; Scale inhibition; Morphology; Crystal Growth; Polymorphism
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2021.126108

•Effect of EDTA on Polymorphic and Morphological changes of CaCO3 in presence of Mg2+ ions reported.•Presence of Mg2+ ions inhibit aragonite and facilitate vaterite formation with EDTA.•A two stage mechanism for the scale inhibition by the inhibitor has been proposed. Calcium carbonate scale formation in the presence of magnesium ions has been studied between 60 and 100 °C. The samples were characterized using XRD, FTIR and FE-SEM techniques. The effect of EDTA on the polymorphism and morphology of calcium carbonate in presence of magnesium ions also have been reported. The study revealed that both magnesium and EDTA influence the crystallization behavior and morphology of the CaCO3 formed. The study also revealed that the effect need not be same under different temperatures and environments and the morphological transformation need not compulsorily represent the polymorphic transformation. The findings are explained by a two stage mechanism which revealed that the magnesium ions present in the system can favorably or adversely affect the scale inhibition property of the inhibitor depending on the concentration and temperature.