Abstract
This study investigates the effect of operating variables and influence of milk of lime (MOL) conditions in PCC using a modified reactor. The variables includes: Ca(OH)2 feed concentration at 0.5 M–2.0 M and CO2 flow rates at 224.0 mL min–1 and 379.5mL min–1, on the particle morphology and size in the gas–liquid route precipitation. The particle morphology and texture as well as the chemical content were sufficiently authenticated using X-ray diffraction (XRD), Fourier transforminfrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-ray fluorescence (XRF). Experimental data show that lower concentration (<1.0 M) favoured the formation of rhombohedra calcite crystals with the particle size below 100 nm. However, increase in concentration and gas flow rate yielded a coarser crystal particles.Two polymorphs were produced at 1M reactant, i.e. rhombohedra calcite with CO2 flow rate of 224 mL min–1 and prismatic calcite at 380 mL min–1. Molarities higher than 1 M yielded a coarser prismatic crystals, and also has a tendency to crystallize into scalenohedron species especially with higher reactant concentration.
Highlights
Precipitated calcium carbonate (PCC) is a filler used in many applications, like papers, plastics, rubbers, paints, drugs and so on
The rate of recarbonation seems directly related to the reactant concentration, bubbling time and CO2 gas flow rate conditions, and eventually affects the characteristics of the resulting PCC
During the course of precipitation, the pH, conductivity (Fig. 2) and total dissolved solid (TDS) values gradually decreases in tandem with the progress of recarbonation process and abruptly dropped to the lowest level at specific moments during the course of precipitation
Summary
Precipitated calcium carbonate (PCC) is a filler used in many applications, like papers, plastics, rubbers, paints, drugs and so on. Carbonation is generally carried out in a series of reactors under closely controlled operating conditions to produce the required PCC morphology and particle size distribution (PSD). This work investigates the transition effects of reactant concentration and gas flow rate on PCC morphology and crystallite size using gas–liquid route via a modified batch-wise, bubblecolumn type reactor.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
