Calcium carbonate sintered body and method for producing same, and bone grafting material

A method for producing a calcium carbonate sintered body, the method comprising the steps of:

• compacting calcium carbonate to make a green body;
• heating the green body under a condition of a temperature of 500° C. or lower in an oxygen gas atmosphere to remove an organic component contained in the green body;
• and sintering the green body under conditions of a carbon dioxide atmosphere and a temperature of 500° C. or higher without adding a sintering aid, or adding a sintering aid so that the content of the sintering aid is 1.5% by mass or less in the mixture of the calcium carbonate and the sintering aid to obtain a calcium carbonate sintered body, wherein in using high-purity calcium carbonate having a purity of 99.7% by mass or more, the sintering temperature of the green body is 650° C. to 800° C., and in using calcium carbonate having a purity of less than 99.7% by mass, the sintering temperature of the green body is 800° C. to 900° C., and wherein the calcium carbonate has an average particle diameter of 0.05 μm to 0.30 μm in a particle diameter distribution measured by transmission electron microscopy and a BET specific surface area of 5 m2/g to 25 m2/g.