Introducing calcium carbonate into cellulosic fiber suspension, adds calcium hydroxide, de-waters and injects carbon dioxide to precipitate carbonate in moist suspension

摘要

Calcium hydroxide in a liquid or dry form is introduced (44) into the fibrous suspension. Alternatively calcium oxide is added. The suspension is de-watered to a non-fluid, but moist consistency. Gaseous carbon dioxide is introduced into the moist fibrous suspension, resulting in calcium carbonate precipitation. The fibrous suspension is sent to a mixer (12) with stator and rotor in the form of plates (16) and mixed using a low shear energy and under low pressure. An independent claim is included for equipment carrying out the process.