Acta Chimica Slovaca (ACS) publishes papers on fundamental and applied aspects of chemistry, biochemistry, chemical technology, chemical engineering and process control, biotechnology and food technology. Welcome are also topics which include chemical aspects of materials, physical chemistry and chemical physics, analytical chemistry, macromolecular chemistry and biomedical engineering.

Reactivity of calcium carbonate prepared from flue gas desulfurization gypsum

Jana Jurišová *, Vladimír Danielik, Pavel Fellner, Milan Králik, Tomáš Foltinovič a

Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia
a Research Institute of Chemical Technology, VUCHT a.s., Nobelova 34, 836 03 Bratislava, Slovakia

E-mail: * jana.jurisova@stuba.sk

Abstract: Reactivity of various calcium carbonate samples for flue gas desulfurization was tested. Two groups of CaCO3 samples were considered; natural limestone containing calcite phase dominantly and samples prepared by the conversion of gypsum with ammonium and carbon dioxide (precipitated CaCO3) containing different amounts of calcite, aragonite and vaterite. Reactivity of precipitated calcium carbonate depends primarily on the particle size, similarly as in case of industrial samples. The initial reaction rate was comparable with the industrial limestones for samples with the average particle size lower than 15 µm. However, the conversion of laboratory samples was significantly higher after 5 min of the reaction. Phase composition of the precipitated calcium carbonate has a minor but noticeable impact on the reactivity. The presence of vaterite slightly increased the reactivity, which is in accordance with its lower compact structure in comparison with calcite and aragonite. Unexpected effect of the increased content of aragonite, which is the most compact phase in comparison with calcite and vaterite, was observed. If calcium carbonate contains up to approximately 30 % of aragonite the reactivity increases, which can be explained by the SEM pictures showing agglomerate composition with relatively high specific surface. At higher contents of aragonite, the reactivity decreases. All the obtained results proved the suitability of precipitated CaCO3 prepared from flue gas desulfurization gypsum to be recycled in the flue gas desulfurization process.

Keywords: flue gas desulfurization, CaCO3 reactivity, aragonite, calcite, vaterite

Full paper in Portable Document Format: acs_0320.pdf

Acta Chimica Slovaca, Vol. 12, No. 1, 2019, pp. 14—21, DOI: 10.2478/acs-2019-0003