Abstract: Influence of calcining technology on the activity of calcined dolomite was investigated．Results showed that the calcining temperatures should be controlled at 995 ℃，1 005 ℃，and 1 020 ℃ for the dolomite with particle size of 5~15 mm， 15~20 mm，and 20~30 mm，respectively；at the calcining temperature of 995 ℃，calcination time for the dolomite with grain size of 15~20 mm was at 60~100 min．By the test of carbonation，the reasonable technological conditions were optimized，i.e. the carbonation was conducted under pressure and the pressure was controlled above 0.3 MPa；the temperature was below 35 ℃， the MgO mass concentration in the slurry was 10～12 g/L，and the carbonation time was 50 min.

Key words: dolomite, light magnesium carbonate, pressure carbonation