CARBONATOR AND METHOD FOR MAKING CALCIUM CARBONATE

摘要

The present invention is related to an apparatus and 5a method for making precipitated calcium carbonate (PCC) which compensates for the slow reaction time of carbonation in a manner which reduces or eliminates the undesirable use and expense of added equipment and processes of previously known methods. The method of the invention involves the generation of multiple streams (preferably at least twenty-five streams) of carbon dioxide which are co-currently introduced to a flow of calcium hydroxide slurry (lime milk). By use of multiple gas streams an intimate mixing of carbon dioxide with the slurry is achieved which compensates for the slow reaction time of carbonation while reducing or eliminating the need for equipment and processes related to recycling, batch operation, serial operation, and long reactor length. An additional benefit of using multiple gas streams in co-current flow is a lower concentration gradient of PCC formed therein facilitating the formation of smaller particles.