The influence of hydrodynamic conditions on the synthesis of ultra-thin calcium carbonate

The paper presents researches on the hydrodynamic conditions in the synthesis of ultra-thin CaCO 3 double-exchange method, using solution of CaCl 2 and Na 2 CO 3 . In all the experiments synthetic solutions, similar to residual solutions resulted in soda industry, have been used. Based on the previous studies for the above mentioned reactants, at the ambient temperature, the influence of angular stirring speed in the range of 100-600 rpm was investigated. The characterization of the obtained solid was carried out using the following techniques: IR Spectroscopy, Thermogravimetry, Laser Diffractometry, Scanning Electron Microscopy- SEM, XRD. The obtained results show that the double-exchange method could be successfully used for synthesis of ultra-thin CaCO 3 , especially in conditions, in which the raw materials are provided as by-products from inorganic chemical industry. The synthesized samples contain mainly calcite, but also traces of vaterite. The experimental parameters were established in order to obtain flat crystals of calcium carbonate, which could be used in paper industry. The hydrodynamic condition did not have any influence over the particles morphology, but influences the grain distribution, depending on the angular stirring speeds.