A carbonation process was developed to coat Al(OH)3 on aragonite whisker. Al(OH)3 coating was obtained in a suspension

which contained 3Cao·Al2O3·6H2O(C3AH6)-NaOH prepared by adding Ca(OH)2 to NaAlO2 aqueous solution.The CaCO3 whiskers coated with fine particles of Al(OH)3 were prepared by blowing CO2 gas into the suspension.The formed Al(OH)3 adhered to the CaCO3 fibers as the substrate.In order to coat α -Al(OH)3 on aragonite whisker

the pH value of the solution must be higher than 10.5.The formation of C3AH6 and complexation of calcium carbonate molecule with C3A were the domain factors to get single aragonite phase whisker. Micro-analysis demonstrated that the existence of Al(OH)3 crystal coating on the surface of aragonite-type calcium carbonate whisker.After the coated whiskers were treated strongly in an ultrasonic water bath.Al(OH)3 still adhered to the CaCO3 whiskers well.The reaction mechanism was also mentioned in this paper.