Solidification method of carbon dioxide by mineral carbonation

A solidification method of carbon dioxide is provided to increase the contents of alkaline substances to be reacted to the carbon dioxide by removing impurities and secure more effective mineral carbonation reactions than existing reactions through a liquid-to-liquid ionization reaction. A solidification method of carbon dioxide comprises the following steps of: pulverizing slag generated in an iron industry; collecting iron using a gravity separator or a magnetic separator; leaching salts from the iron-removed slag, which indicates calcium oxide, magnesium oxide, potassium oxide, sodium oxide and water-immiscible materials, using acetic acid; separating water-immiscible materials and aqueous solutions wherein calcium acetate, magnesium acetate, potassium acetate and sodium acetate are dissolved in a setting tank; and injecting carbon dioxide to the separated aqueous solutions to obtain and separate calcium carbonate, magnesium carbonate, potassium carbonate, sodium carbonate and acetic acid.