Process for the continuous production of precipitated calcium carbonate
OwnerChristoph Nover, Helmut Dillenburginventors
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Abstract
A process for continuously producing precipitated calcium carbonate having a controllable particle diameter, in which nucleation and crystal growth are carried out in separate phases or phases. The size of the calcium carbonate particles is determined and/or controlled by the concentration of the calcium hydroxide suspension and by the ratio of CO2 introduced to the volume of Ca(OH)2 suspension as early as in the nucleation phase.
Claims7
A process for continuously producing precipitated calcium carbonate having a controllable particle size, comprising reacting a flow of calcium hydroxide with a flow of CO2 in a nucleation phase in which predominantly calcium carbonate nuclei are formed and in a separate crystal growth phase in which predominantly the nuclei formed in the nucleation phase grow in accordance with the calcium hydroxide and the CO2 availability, and controlling the particle size of the precipitated calcium carbonate through the concentration of the calcium carbonate nuclei formed in the nucleation phase, by varying the volume ratio of the CO2 flow introduced into the calcium hydroxide flow by
- a) by regulating the calcium hydroxide flow volume at a constant reactor volume and a constant CO2 flow volume, or
- b) by regulating the CO2 flow volume at a constant calcium hydroxide flow volume and a constant reactor volume.
Dependencies are inferred from the claim text.