Abstract: The influence of the calcite matrixes on migration of Na + and alkali-dolomite reaction was studied in dolomitic limestone .The sizes of the calcite particles in dolomitic limestones were measured by using microscopic image analysis method .The pore size distribution of dolomitic limestones was measured by using N2-adsorption method .The content of Na +ions in sections of the rock prisms was measured by flame emission spectroscopy . Brucite formed by alkali-dolomite reaction ( ADR ) was quantitatively analyzed by XRD in the dolomitic limestones .The results indicate that the median diameters of the calcite in the dolomitic limestones TS-1, TS-2, GS-2 and FHS-1 were 4 μm, 12 μm, 15 μm and 33 μm, respectively .The smaller the size of calcite particles was , the higher the content of Na +migrated in the rock, the higher the dedolomitization of dolomite in the rock would be .

Key words: particle size of calcite;alkali-dolomite reaction;dolomitic limestone