| abstract |
A granular material composed of porous particles containing calcium oxide or porous particles containing calcium oxide and magnesium oxide is provided as a granular material having a high BET specific surface area and high strength. Porous particles containing calcium oxide and calcium hydroxide, wherein the ratio of calcium oxide content to the total amount of calcium oxide content and calcium hydroxide content is in the range of 30 to 80 mass%, and the BET specific surface area is 40 m 2 / g or more. Porous particles comprising calcium oxide, magnesium oxide, calcium hydroxide and magnesium hydroxide, wherein the mass ratio of magnesium content to the total amount of calcium content and magnesium content is in the range of 0.05 to 0.80, and the total hydroxyl groups in the particles. The granular material which consists of porous particles whose content rate is in the range of 1-20 mass%, and whose BET specific surface area is 50 m <2> / g or more. |