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 ?
Test piece for determination of RUL of a refractory is heated in a/an__________________?
With increase in the alumina content, the refractoriness of high alumina refractories_________________?
Thermal diffusivity of a refractory brick is high, when its ______________ is high?
Answer: Thermal conductivity
Fusion point of a basic refractory material is________________?
Answer: Reduced by the addition of acid oxides
Fireclay bricks are used in the______________?
Answer: Coke ovens regenerator
High porosity refractory bricks have________________?
Fireclay bricks are not used in the________________?
Answer: By-product coke oven walls
Hot metal runner in blast furnace are lined with ______________ bricks?
Presence of MgO in alumino-silicate refractories ______________ its refractoriness ?
Chemically, mullite refractories is________________?
Panel test determines the ______________ of refractories?
Answer: Spalling resistance
Maximum alumina content in high alumina refractory can be as high as ____________ percent?
Water content in ground refractory material to be shaped into bricks by hand moulding is about _____________ percent?
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______________?
Refractory bricks with lower permeability is produced by using _________________?
Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to__________________?
Addition of zircon to silica refractory brick improves its_________________?
Answer: Resistance to slag attack
Pick out the wrong statement?
Answer: Generally, the heat capacities of compounds are lower in the liquid than in the solid state