Xinjiang Zhundong coal has abundant reserves and contains a relatively high content of alkaline earth metal elements. The high-calcium fly ash generated from its combustion serves as an excellent raw material for CO2 sequestration. By adopting the atmospheric pressure direct wet carbonation process

research and optimization analysis were carried out on the carbonation of high-calcium fly ash

focusing on key parameters such as flue gas flow rate

temperature

and solid-liquid ratio. A kinetic model was constructed to determine the key factors and rate-controlling steps. Meanwhile

the performance of this process in chlorine removal and heavy metal removal was evaluated. It was found that

increasing the flue gas flow rate and reducing the solid-liquid ratio can effectively enhance the degree of carbonation per unit mass of fly ash. During the rapid carbonation stage(0～20 min)

low temperature is beneficial for increasing the degree of carbonation

but the effect is not significant. In the rapid carbonation zone

the reaction of fly ash is mainly controlled by solid-film diffusion

with a correlation coefficient of 0.917 37 and an activation energy of 10.36 kJ/mol. After optimization by the response surface method

the optimal operating condition parameters are as follows: temperature of 57.1 ℃

flue gas flow rate of 2.86 L/min

and solid-liquid ratio of 200.0 g/L. Under these conditions

the average actual degree of carbonation reaches 30.2%. The chlorine content of the fly ash processed according to these parameters meets the requirements for reinforced products in the JC/T 409—2016 standard. For typical heavy metals such as arsenic and copper

the removal rates reach 88.4% and 55.6% respectively

indicating that this process has a certain detoxification ability. Therefore

the atmospheric wet carbonation of high calcium fly ash in Zhundong has great potential for application.