Preparation of Synthetic Calcium Carbonate by Continuous Method

Abstract

The production of precipitated calcium carbonate (PCC) was performed by a continuous method with additional mechanical stirring and retardant agent after the carbonation process. The PCC was produced at four different conditions i.e. without stirring and retardant agent (XSR), PCC with stirring only (S0), PCC with stirring, and 4g of a retardant agent (S4), and PCC with stirring and 20g of a retardant agent (S20). The continuous method 1 L of PCC slurry was consistently achieved at 7 minutes of the carbonation time that was controlled for all samples. The PCC yield was generally consistent with a slight reduction with increasing the retardant agent weight. Laser Particle Size Analyzer (LPSA) showed the finest PCC, which is 5.093 μm was produced without any additional mechanism (XSR) after the carbonation process. FESEM micrographs showed there were two types of PCC structure particles; fine hollow shape and coarse irregular shape. The result of Zeta potential portrayed the negative Zeta values for all samples with the highest values of -2.9 mV for S0 sample. The high purity of high-grade calcium carbonate for all samples was determined using X-ray Fluorescence (XRF). In general, there was no significant change occurred in the morphology of the PCC but offered a larger effect on particle refinement. Meanwhile, mechanical stirring resulted in an increment of the PCC particle size, but the retardant agent provided a particle refinement effect.