Ammonia carbonation product control is the key of calcium sulfate conversion at low temperature for utilization of sulfur resources.Aspen plus software was used to simulate ammonia carbonation process.The results indicate that carbonate converts gradually into bicarbonate with increasing temperature from 273.15 K to 338.15 K. The conversion from bicarbonate to carbonate occurs at 0.01—0.13 MPa

but ammonia carbonation has no affect when pressure is above 0.13 MPa. If ammonia mole fraction is less than 0.04

bicarbonate mole fraction in products will be close to 1. When ammonia mole fraction is 0.1—0.15 or ratio of reaction ammonia to carbon oxide 2.2—2.8

carbonate is the major product of carbonation.If ammonia mole fraction is above 0.15

effect of ammonia concentration on ammonia carbonization is little.When ratio of reaction ammonia to carbon oxide is higher than 2.8

There will be more than 90% of ammonium bicarbonate in solution.On the basis above

control conditions of temperature-ammonia concentration

temperature-ratio of reactive ammonia to carbon dioxide were pointed out for preparing high contents of ammonium bicarbonate or ammonium carbonate.