METHOD FOR CONTROLLING FORM OF VATERITE-TYPE CALCIUM CARBONATE AND METHOD FOR GROWING PARTICLE

摘要

PURPOSE: To easily and stably perform the subject processes by carrying out a specific reaction in a mixed system consisting of a vaterite-type calcium carbonate used as a base material, methanol, water and quick lime and/or slaked lime. ;CONSTITUTION: The control of form and the growth of particle of a vaterite-type calcium carbonate having the form defined by formula (DS1 is average particle diameter μm of the major axis of the primary particles measured by a scanning electron microscope) can be performed by charging (A) a carbonation reaction system with (B) water corresponding to 0.1-80 times mol based on calcium carbonate and quick lime and/or staked lime existing in the system A in terms of quick lime, charging the system A with (C) 0.1-25wt.% of calcium carbonate and quick lime and/or slaked lime in terms of solid component of quick lime based on methanol existing in the system and passing CO₂ gas through the reaction system consisting of a mixture of B and C to control the system to pH 5.6-11.5 and 15-60°C and control the electrical conductance of the system A to 2-1,000μS to perform the carbonation reaction.;COPYRIGHT: (C)1993,JPO&Japio