Patent Number: 
Section: claims

1. A silicotitanate molded body comprising:crystalline silicotitanate particles that have a particle size distribution in which 90% or more, on volume basis, of the particles have a particle size within a range of 1 μm or more and 10 μm or less and that are represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; andan oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium. 2. The silicotitanate molded body according to claim 1, further comprising niobium. 3. The silicotitanate molded body according to claim 2, wherein the silicotitanate molded body has a compressive strength at failure of 5.0 N or more. 4. The silicotitanate molded body according to claim 1, wherein a content of the oxide of one or more elements selected from the group of aluminum, zirconium, iron, and cerium is 20 wt % or less. 5. The silicotitanate molded body according to claim 1, wherein the molded body has a cylindrical shape having an average diameter within a range of 300 μm or more and 3,000 μm or less. 6. An adsorbent for cesium and/or strontium, comprising the silicotitanate molded body according to claim 1. 7. A decontamination method of a radioactive waste solution, comprising bringing an adsorbent for cesium and/or strontium comprising the silicotitanate molded body according to claim 1 into contact with a waste solution containing radioactive cesium and/or radioactive strontium. 8. The decontamination method of a radioactive waste solution according to claim 7, comprising bringing the radioactive waste solution into contact with the adsorbent in a column flow mode at a linear velocity LV of 2 m/h or more and 40 m/h or less and a space velocity SV of 10 h−1 or more and 300 h−1 or less. 9. A production method of the silicotitanate molded body according to claim 1, comprising:extruding a mixture containing crystalline silicotitanate that has a particle size distribution in which 90% or more, on volume basis, of particles have a particle size within a range of 1 μm or more and 10 μm or less and that is represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; and an oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium to form a molded body; and subsequentlydrying the molded body. 10. An adsorbent for cesium and/or strontium, comprising the silicotitanate molded body according to claim 2. 11. An adsorbent for cesium and/or strontium, comprising the silicotitanate molded body according to claim 3. 12. An adsorbent for cesium and/or strontium, comprising the silicotitanate molded body according to claim 4. 13. An adsorbent for cesium and/or strontium, comprising the silicotitanate molded body according to claim 5. 14. A decontamination method of a radioactive waste solution, comprising bringing an adsorbent for cesium and/or strontium comprising the silicotitanate molded body according to claim 2 into contact with a waste solution containing radioactive cesium and/or radioactive strontium. 15. A decontamination method of a radioactive waste solution, comprising bringing an adsorbent for cesium and/or strontium comprising the silicotitanate molded body according to claim 3 into contact with a waste solution containing radioactive cesium and/or radioactive strontium. 16. A decontamination method of a radioactive waste solution, comprising bringing an adsorbent for cesium and/or strontium comprising the silicotitanate molded body according to claim 4 into contact with a waste solution containing radioactive cesium and/or radioactive strontium. 17. A decontamination method of a radioactive waste solution, comprising bringing an adsorbent for cesium and/or strontium comprising the silicotitanate molded body according to claim 5 into contact with a waste solution containing radioactive cesium and/or radioactive strontium. 18. A production method of the silicotitanate molded body according to claim 2, comprising:extruding a mixture containing crystalline silicotitanate that has a particle size distribution in which 90% or more, on volume basis, of particles have a particle size within a range of 1 μm or more and 10 μm or less and that is represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; and an oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium to form a molded body; and subsequentlydrying the molded body. 19. A production method of the silicotitanate molded body according to claim 3, comprising:extruding a mixture containing crystalline silicotitanate that has a particle size distribution in which 90% or more, on volume basis, of particles have a particle size within a range of 1 μm or more and 10 μm or less and that is represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; and an oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium to form a molded body; and subsequentlydrying the molded body. 20. A production method of the silicotitanate molded body according to claim 4, comprising:extruding a mixture containing crystalline silicotitanate that has a particle size distribution in which 90% or more, on volume basis, of particles have a particle size within a range of 1 μm or more and 10 μm or less and that is represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; and an oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium to form a molded body; and subsequentlydrying the molded body. 21. A production method of the silicotitanate molded body according to claim 5, comprising:extruding a mixture containing crystalline silicotitanate that has a particle size distribution in which 90% or more, on volume basis, of particles have a particle size within a range of 1 μm or more and 10 μm or less and that is represented by a general formula of A2Ti2O3(SiO4).nH2O wherein A represents one or two alkali metal elements selected from Na and K, and n represents a number of 0 to 2; and an oxide of one or more elements selected from the group consisting of aluminum, zirconium, iron, and cerium to form a molded body; and subsequentlydrying the molded body.