화학공학소재연구정보센터
Journal of Chemical Engineering of Japan, Vol.35, No.5, 409-414, 2002
Semi-dry process for production of very fine calcium carbonate powder by a powder-particle spouted bed
A new semi-dry process to produce very fine calcium carbonate powder is developed. Ca(OH)(2) slurry droplets are continuously fed into a spouted bed of coarse medium particles, and react with CO, in fluidizing gas to produce fine CaCO3 powder. The CaCO3 powder is dried with fluidizing gas, and fine CaCO3 powder is entrained from the bed to be collected with a bag filter. The effect of operating conditions, such as the concentration of the Ca(OH)(2) slurry, CO2 concentration in the fluidizing gas, approach to saturation temperature, superficial gas velocity and static bed height, on the conversion of Ca(OH)(2) to CaCO3 and the particle size of product CaCO3 powder are investigated. Very fine CaCO3 powder and high Ca(OH), conversion are obtained in the case of low concentration of Ca(OH)(2) in the feed slurry and high concentration of CO2 in the fluidizing gas. This method can produce very fine calcium carbonate powders with the mean particle size around I mum and the Ca(OH)(2) conversion around 90%.