Abstract: Micro/nano nesquehonite whiskers were synthesized with magnesite method. The effects of raw materials from different regions， pyrolysis temperatures and types of additive on phase compositions and morphology of products were respectively investigated by means of XRD and SEM. The results showed that well crystallized rodlike nesquehonite whiskers with high aspect ratio can be synthesized at the optimal pyrolysis temperature of 50 ℃， using magnesite from Kuandian and Xiuyan as raw materials. Nesquehonite whiskers become unstable when the pyrolysis temperature is over 50 ℃. The results of SEM analysis showed that pyrolysis products obtained are irregular rodlike and acicular mixed crystal without any additive. Smooth rodlike crystals with high aspect ratio were obtained with additive of absolute alcohol and sodium dodecyl sulfate. Stubby aggregates were obtained with additive of sodium polyphosphate. The essence of magnesite method was that Mg(HCO3)2 precursor solution was prepared by calcination， hydration and carbonation treatment using magnesite as raw material， then nesquehonite crystals could be synthesized through the pyrolysis of Mg(HCO3)2 solution.

Key words: magnesite method, synthesis, nesquehonite whiskers, pyrolysis temperature, mechanism