1. Panel test determines the __________ of refractories.
2. Fireclay bricks are not used in the
3. Fusion point of a basic refractory material is
4. RUL of refractories depends on the
5. Which is the stable form of silica between 1470°C and the melting point 1713°C ?
6. Resistance to slag attack of a refractory
7. Grog
8. Test piece for determination of RUL of a refractory is heated in a/an
9. Magnesite refractories are used for the construction of those furnaces, which are
10. Roof of a basic electric furnace is made of __________ bricks.
11. Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
12. Magnesite bricks are used in those parts of furnaces, which are
13. Which is not a basic refractory ?
14. Thoria
15. Which property of refractories is the most important for top section of the blast furnace?
16. Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
17. Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except
18. An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture ?
19. Firing of refractory brick is done to
20. Chemically, mullite refractories is
21. Thermal diffusivity of a refractory brick is high, when its __________ is high.
22. High porosity refractory bricks have
23. Vacuum steel degassing units are lined with
24. Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
25. Which is the stable form of silica below 870°C ?