Binder for monolithic refractories, monolithic refractory, and construction method of monolithic refractories

1. A binder for monolithic refractories comprising

a solid solution obtained by dissolving Ca components in α-SrAl 2 O 4 or β-SrAl 2 O 4 ,

wherein when the Ca components are dissolved in the α-SrAl 2 O 4 , a crystallite diameter of the solid solution is from 40 nm to 75 nm, and

when the Ca components are dissolved in the β-SrAl 2 O 4 , a crystallite diameter of the solid solution is from 35 nm to 70 nm.

2. The binder for monolithic refractories according to claim 1 ,

wherein an amount of the solid solution obtained by dissolving Ca components in the α-SrAl 2 O 4 or the β-SrAl 2 O 4 is from 10 mass % to 60 mass %, and

40 mass % to 90 mass % of Al 2 O 3 is blended thereinto.

3. The binder for monolithic refractories according to claim 1 , further comprising, as a mixture,

a solid solution obtained by dissolving Sr components in CaAl 2 O 4 ,

wherein a crystallite diameter of the solid solution is from 25 nm to 60 nm.

4. The binder for monolithic refractories according to claim 3 ,

wherein an amount of the solid solution obtained by dissolving Ca components in the α-SrAl 2 O 4 or the β-SrAl 2 O 4 and the solid solution obtained by dissolving Sr components in the CaAl 2 O 4 is from 10 mass % to 60 mass %, and

40 mass % to 90 mass % of Al 2 O 3 is blended thereinto.

5. The binder for monolithic refractories according to claim 1 ,

wherein both of a solid solution obtained by dissolving Ca components in the α-SrAl 2 O 4 and a solid solution obtained by dissolving Ca components in the β-SrAl 2 O 4 are included as a mixture.

6. The binder for monolithic refractories according to claim 5 ,

wherein a total amount of both of the solid solution obtained by dissolving Ca components in the α-SrAl 2 O 4 and the solid solution obtained by dissolving Ca components in the β-SrAl 2 O 4 is from 10 mass % to 60 mass %, and

40 mass % to 90 mass % of Al 2 O 3 is blended thereinto.

7. The binder for monolithic refractories according to claim 5 , further comprising, as a mixture

the solid solution obtained by dissolving Sr components in the CaAl 2 O 4 .

8. The binder for monolithic refractories according to claim 7 ,

wherein a total amount of the solid solution obtained by dissolving Ca components in the α-SrAl 2 O 4 , the solid solution obtained by dissolving Ca components in the β-SrAl 2 O 4 , and the solid solution obtained by dissolving Sr components in the CaAl 2 O 4 is from 10 mass % to 60 mass %, and

40 mass % to 90 mass % of Al 2 O 3 is blended thereinto.

9. The binder for monolithic refractories according to claim 1 ,

wherein at least one selected from a group consisting of SiO 2 , TiO 2 , Fe 2 O 3 , MgO, and BaO are included in the binder for monolithic refractories and an amount thereof is 12 mass % or less.

10. The binder for monolithic refractories according to claim 1 ,

wherein at least one of a dispersant and a hardening retardant is blended into the binder for monolithic refractories.

11. A monolithic refractory obtained by blending the binder for monolithic refractories according to any one of claims 1 to 10 into a refractory aggregate.

12. The monolithic refractory according to claim 11 ,

wherein the refractory aggregate includes an ultrafine alumina powder with a particle diameter of from 0.8 nm to 1 μm.

13. The monolithic refractory according to claim 11 ,

wherein an amount of the binder for monolithic refractories is from 0.3 mass % to 20 mass % with respect to 100 mass % of a total amount of the binder for monolithic refractories and the refractory aggregate.

14. The monolithic refractory according to claim 13 ,

wherein the amount of the binder for monolithic refractories is from 0.5 mass % to 12 mass % with respect to 100 mass % of the total amount of the binder for monolithic refractories and the refractory aggregate.

15. The monolithic refractory according to claim 11 ,

wherein further at least one of a dispersant, a hardening retardant, and a hardening accelerator is added.

16. The monolithic refractory according to claim 15 ,

wherein the dispersant is at least one selected from a group consisting of a polycarbonate-based dispersant, a phosphate-based dispersant, an oxycarboxylic acid, a melamine-based dispersant, a naphthalene-based dispersant, and a lignin sulfonic acid-based dispersant,

the hardening accelerator is at least one of an alkali metal salt and aluminate, and

the hardening retardant is at least one of boric acid group and silicofluoride.

17. A construction method of monolithic refractories comprising:

blending and mixing the binder for monolithic refractories according to any one of claims 1 to 10 and a refractory aggregate including an ultrafine alumina powder with a particle diameter of 1 μm or less to obtain a monolithic refractory; and

constructing the monolithic refractory.