Effect of various factors on the particle size of calcium carbonate formed in a precipitation process

Abstract

The effect of various factors on the particle size of precipitated calcium carbonate formed in a wet carbonation process has been investigated experimentally. The calcium carbonate particles were fabricated in a glass reactor by bubbling CO 2 through a calcium hydroxide solution of 2.5% by weight. The particle size distribution of the particles was determined using a laser technique. The operating factors investigated include the CO 2 bubble size (with frit pore size of 17–40 or 101–160 μm), the CO 2 gas flow rate (3.5 and 4 L/min), the CO 2 concentration (25 and 100%), the reaction temperature (25 and 80 °C) and the additives (terpineol 0.1 and 1 vol%, EDTA 0.25 and 1 wt%). It was found that the average particle size was between 1 and 3 μm. The particle size was reduced slightly with the decrease of the CO 2 bubble size, and decrease of the CO 2 concentration. The particle size distribution was affected significantly by the addition of terpineol and EDTA, but not necessarily reduced as reported previously.