Abstract: Technological conditions in preparation of anhydrous calcium chloride with ammonium chloride as chlorinating agent to roasting chlorinate calcium carbonate were studied．The influences of roasting temperature，dosing ratio of reactants， roasting time，and thickness of material loading were investigated by single factor experiments.The anhydrous calcium chlo- ride product was characterized by XRD．The optimum experimental conditions were obtained: roasting temperature was 450 ℃， roasting time was 60 min，dosing ratio of n（NH₄Cl）∶n（CaCO₃）=3:1，and loading thickness was greater than 1 cm.Under these conditions，the chlorinating rate of calcium carbonate reached 95.8%，calcined product of anhydrous calcium chloride mass percentage was 94.96%.In industrial size，industrial heavy calcium carbonate with 10.5 μm and industrial ammonium chlo- ride were roasted for 120 min，the chlorinating rate of calcium carbonate reached 95.19%，and calcined product of anhydrous calcium chloride mass percentage was 94.83%.

Key words: ammonium chloride；chlorination roasting；calcium carbonate；anhydrous calcium chloride
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