METHOD OF ELUTING CALCIUM FROM STEELMAKING SLAG AND METHOD OF RECOVERING CALCIUM FROM STEELMAKING SLAG

PROBLEM TO BE SOLVED: To provide a method for eluting Ca from a steelmaking slag capable of eluting a large amount of Ca from a steelmaking slag into an aqueous solution containing carbon dioxide.SOLUTION: A step in which compounds containing iron are removed from steelmaking slag by applying magnetic separation to the steelmaking slag and a step in which the steelmaking slag subjected to the magnetic separation is brought into contact with an aqueous solution containing carbon dioxide are performed in this order. Further, the steelmaking slag is brought into contact with the aqueous solution containing carbon dioxide while the steelmaking slag is pulverized or surface of the steelmaking slag is ground. Through these methods, a large amount of Ca can easily be eluted from the steelmaking slag into the aqueous solution containing carbon dioxide.SELECTED DRAWING: Figure 1 【課題】多量のＣａを製鋼スラグから二酸化炭素を含有する水溶液へ溶出させることができる、製鋼スラグからＣａを溶出させる方法を提供すること。【解決手段】製鋼スラグに磁選を施して、鉄を含む化合物を前記製鋼スラグから取り除く工程と、前記磁選を施した製鋼スラグと二酸化炭素を含有する水溶液とを接触させる工程と、をこの順で行う。また、製鋼スラグを粉砕しながら、または製鋼スラグの表面を摩砕しながら、二酸化炭素を含有する水溶液と製鋼スラグとを接触させる。これらの方法により、容易に、多量のＣａを製鋼スラグから二酸化炭素を含有する水溶液へ溶出させることができる。【選択図】図１