The effect of CO₂ gas flow rate on precipitated CaCO₃ formed at room temperature Free

Synthesis of precipitated CaCO₃ from limestone Blumbungan, Madura island (East Java, Indonesia) using carbonation process have been done. The carbonation process is carried out with variations of the CO₂ gas flow rate of 1.175, 2.35, 3.525 and 4.7 l/min at room temperature. The crystalline phase formed was characterized by X-ray diffraction (XRD) X-Pert MPD with Cu-K_α radiation (λ = 1,5406 Ǻ) and scanned from 10° to 60°. The morphological investigation was analyzed by Scanning Electron microscope (SEM) FEI Inspect S50 X’pertPRO PANalytical. Crystal size was analyzed using the Scherrer equation. The XRD test results show that the phases formed at CO₂ gas flow rates 1.175, 2.35, and 3.525 l/min are vaterite and calcite, while at 4.7l/min only calcite phase is formed. Variations in CO₂ gas flow rate affect the percentage of calcite and vaterite formed. The crystal size of precipitated CaCO₃ the Scherrer equation ranged from 55,572 – 81,290 nm. The morphology of precipitated CaCO³ is mix rhombohedral cubic and needle-like.