Molten glass conveying equipment element, method for manufacturing molten glass conveying equipment element, glass manufacturing apparatus comprising molten glass conveying equipment element and method for manufacturing glass product

1. A method for producing a molten glass conveying equipment element having a conduit structure for molten glass containing at least one conduit comprising platinum or a platinum alloy, a first ceramic structure provided around the conduit and a second ceramic structure located around the first ceramic structure, the method comprising:

filling a gap between the conduit and the second ceramic structure with a slurry body, the slurry body being prepared by blending: first particles having a median diameter D50 of 0.2 to 10 μm and containing, in terms of mass % to an entire composition, 90 wt % or more of zirconium oxide; second particles having a median diameter D50 of 0.2 to 2 mm and containing, in terms of mass % to the entire composition, 75 wt % or more of zirconium oxide, in which a proportion of cubic zirconia in the zirconium oxide is 80 wt % or more, and containing at least one of stabilizers selected from the group consisting of yttrium oxide and cerium oxide in a total content of 6 to 25 wt %; and third particles having a median diameter D50 of 1 to 500 μm and containing, in terms of mass % to the entire composition, 50 wt % or more of silicon dioxide, so as to satisfy that a mass ratio of a mass of the first particles to a mass of the second particles (mass of the first particles/mass of the second particles) is 0.25 to 0.6, and a mass ratio of a mass of the third particles in terms of silicon dioxide to a total mass of the first particles and the second particles (mass of the third particles in terms of silicon dioxide/(mass of the first particles+mass of the second particles)) is 0.05 to 0.2; and

sintering the slurry body at a temperature of 1,300 to 1,550° C., thereby forming the first ceramic structure.

2. The method for producing a molten glass conveying equipment element according to claim 1 , wherein the gap between the conduit and the second ceramic structure is filled with the slurry body so as to satisfy that the mass ratio of the mass of the first particles to the mass of the second particles (mass of the first particles/mass of the second particles) is 0.3 to 0.6, a mass ratio of a mass of the third particles in terms of silicon dioxide to the mass of the first particles (mass of the third particles in terms of silicon dioxide/mass of the first particles) is 0.1 to 0.9.

3. The method for producing a molten glass conveying equipment element according to claim 1 , wherein the third particles substantially consist of only the silicon dioxide.

4. The method for producing a molten glass conveying equipment element according to claim 2 , wherein the third particles substantially consist of only the silicon dioxide.

5. The method for producing a molten glass conveying equipment element according to claim 3 , wherein the median diameter D50 of the third particles is 10 to 300 μm.

6. The method for producing a molten glass conveying equipment element according to claim 4 , wherein the median diameter D50 of the third particles is 10 to 300 μm.

7. The method for producing a molten glass conveying equipment element according to claim 1 , wherein the third particles are glass particles which contain, in terms of mass % to the entire composition, 50 wt % or more of the silicon dioxide.

8. The method for producing a molten glass conveying equipment element according to claim 2 , wherein the third particles are glass particles which contain, in terms of mass % to the entire composition, 50 wt % or more of the silicon dioxide.

9. The method for producing a molten glass conveying equipment element according to claim 7 , wherein the median diameter D50 of the third particles is 20 to 100 μm.

10. The method for producing a molten glass conveying equipment element according to claim 8 , wherein the median diameter D50 of the third particles is 20 to 100 μm.

11. The method for producing a molten glass conveying equipment element according to claim 1 , wherein the conduit includes a conduit having at least one of a convex portion and a concave portion, which continues 360° in a circumferential direction.

12. The method for producing a molten glass conveying equipment element according to claim 2 , wherein the conduit includes a conduit having at least one of a convex portion and a concave portion, which continues 360° in a circumferential direction.

13. The method for producing a molten glass conveying equipment element according to claim 1 , wherein the conduit includes a conduit having a stirrer provided inside thereof.

14. The method for producing a molten glass conveying equipment element according to claim 2 , wherein the conduit includes a conduit having a stirrer provided inside thereof.

15. The method for producing a molten glass conveying equipment element according to claim 1 , wherein cumulative undersize 90% diameter (D90) of the first particles is 15 μm or less and cumulative undersize 10% diameter (D10) of the second particles is 0.1 mm or more.

16. The method for producing a molten glass conveying equipment element according to claim 2 , wherein cumulative undersize 90% diameter (D90) of the first particles is 15 μm or less and cumulative undersize 10% diameter (D10) of the second particles is 0.1 mm or more.

17. A molten glass conveying equipment element having a conduit structure for molten glass containing at least one conduit comprising platinum or a platinum alloy, a first ceramic structure provided around the conduit and a second ceramic structure located around the first ceramic structure,

wherein the first ceramic structure contains: in terms of mass % to an entire composition, 65 wt % or more of zirconium oxide, in which a proportion of cubic zirconia in the zirconium oxide is 60 wt % or more; and 1 to 20 wt % of zircon (ZrSiO 4 ), and

an average open porosity of the first ceramic structure is 20 to 60%, a coefficient of linear thermal expansion at 20 to 1,000° C. of the first ceramic structure is 8×10 −6 to 12×10 −6 /° C. and the gap between the conduit and the first ceramic structure is less than 0.5 mm.

18. The molten glass conveying equipment element according to claim 17 , wherein a mass ratio of a total mass of yttrium oxide and cerium oxide to a mass of zirconium oxide contained in the first ceramic structure (total mass of yttrium oxide and cerium oxide/mass of zirconium oxide) is 0.05 to 0.25.

19. The molten glass conveying equipment element according to claim 18 , wherein the mass ratio of the total mass of yttrium oxide and cerium oxide to the mass of zirconium oxide contained in the first ceramic structure (total mass of yttrium oxide and cerium oxide/mass of zirconium oxide) is 0.05 to 0.08.

20. The molten glass conveying equipment element according to claim 17 , wherein compression strength at 1,400° C. of the first ceramic structure is 5 MPa or more.

21. The molten glass conveying equipment element according to claim 18 , wherein compression strength at 1,400° C. of the first ceramic structure is 5 MPa or more.

22. The molten glass conveying equipment element according to claim 19 , wherein compression strength at 1,400° C. of the first ceramic structure is 5 MPa or more.

23. A glass manufacturing apparatus, including the molten glass conveying equipment element according to claim 17 .

24. A method for producing a glass article using the glass manufacturing apparatus according to claim 23 , the method comprising:

heating a glass material, thereby obtaining molten glass; and

forming and annealing the molten glass, thereby obtaining the glass article.