Question: Silica bricks are never used for lining the____________________?

• 1. Beehive coke ovens
• 2. By-product coke ovens
• 3. Dome of blast furnace stoves
• 4. Roof of open hearth furnace

Question: Fireclay bricks is not used for lining the__________________?

• 1. Cupola
• 2. Gas producer
• 3. Bottom of hot metal mixer
• 4. Roof of open hearth furnace

Question: In panel test for spalling resistance, the average face temperature of panel assembly is maintained at ______________ °C for 24 hours?

• 1. 700
• 2. 1000
• 3. 1600
• 4. 2000

Question: Which is an acidic refractory ?

• 1. Magnesite
• 2. Dolomite
• 3. Fireclay
• 4. Chrome magnesite

Question: Which is not an acidic refractory ?

• 1. Silica
• 2. Fireclay
• 3. High alumina refractory
• 4. Carbon black

Question: Fusion point of a basic refractory material is__________________?

• 1. Reduced by the addition of acid oxides
• 2. Increased by the addition of acid oxides
• 3. Not affected by the addition of acid oxides
• 4. Always less than 1000°C

Question: Thermal conductivity of refractory bricks_________________?

• 1. Increases with decrease in porosity
• 2. Decreases with decreases in porosity
• 3. Is independent of its porosity and is maximum for insulating bricks
• 4. Increases with the amount of air entrapped in pores

Question: Which form of silica has the highest specific gravity ?

• 1. Quartz
• 2. Cristobalite
• 3. Tridymite
• 4. All have the same specific gravity

Question: Fireclay bricks are not used in the_____________________?

• 1. Blast furnace
• 2. Hot blast stove
• 3. Cupola
• 4. Wall of coke oven

Question: Permeability of bricks is a measure of the_________________?

• 1. Refractoriness
• 2. Melting point
• 3. Rate at which a fluid will pass through the pores
• 4. Expansion during heating