Circulation process for mineralizing carbon dioxide by magnesium slag

The invention discloses a circulation process for mineralizing carbon dioxide by magnesium slag, which comprises the following steps: step 1, coarsely grinding cooled magnesium slag until the particle size does not exceed 150 meshes to obtain a coarse grinding material; 2, 1-2 mol/L of ammonium chloride solution is added into the coarse grinding material obtained in the step 1, water bath heating is conducted, stirring is conducted till the leaching reaction is conducted for 1-1.5 h, the water bath temperature is 50-60 DEG C, and leaching liquid and filter residues are obtained; and step 3, introducing gas containing carbon dioxide into the leachate obtained in the step 2, stirring and reacting for 3-4 hours, and keeping the temperature at 40-50 DEG C in the whole process to obtain a precipitate and a reaction solution. According to the invention, effective magnesium slag waste heat recovery and emission products (carbon dioxide tail gas) are innovatively coupled, so that waste heat utilization and resource u