Abstract: KAl(OH)₂CO₃ powder was prepared by a hydrothermal method using Al(OH)₃ and KHCO₃ as the starting material.
The influence of the composition of the starting material, reaction temperature, acidity of the reaction medium and reaction time on the formation, morphology
and particle size of KAl(OH)₂CO₃ powder was systematically investigated. The research results show that fibrous particles will be obtained at most
conditions. The length and diameter of particles increase with the ratio of Al(OH)₃ to KHCO₃ or the reaction temperature increasing. The
morphology and particle size of the products are significantly affected by the acidity of the reaction system, and pH=9.5 is optimal for the preparation
of the KAl(OH)₂CO₃ powder with minimal diameter and the best uniformity.

Key words: hydrothermal method, KA1（OH）₂CO₃, nano-powder, dawsonite