Extractive crystallization for the production of calcium acetate and magnesium acetate from carbonate sources

Extractive crystallization was employed for the preparation of deicing compositions of calcium acetate (CA) and magnesium acetate (MA) at room temperature. The design system comprises an aqueous phase as the source of calcium or magnesium ions and an organic phase as the source of acetate ions. The process was designed with the consideration that acetic acid is used in an organic phase as extracted from a fermentation broth. The conditions under which the extractive crystallization methods resulted in the formation of single crystals or aggregates of calcium acetate and magnesium acetate were studied. Furthermore, the effect of acetic acid concentration in the organic and aquoeous phases on the characteristics of the obtained crystals was investigated. Overall, the extractive crystallization process proved to be feasible at least in the laboratory and resulted in the production of well-formed, non-porous, large single crystals and clusters of either calcium acetate acetic acid hydrate [Ca(CH₃COO)₂·CH₃COOH·H₂O] or magnesium acetate tetrahydrate [Mg(CH₃COO)₂·4H₂O, α], depending on the type of salt (CaCO₃ or MgCO₃) used in each case.