Refractory Technology

A. Low co-efficient of expansion
B. High RUL (1600°C) and refractoriness (> 2000°C)
C. High spalling resistance
D. All A., B. and C.

A. Are bonded with lime and clay
B. (Free from silica) have better thermal fatigue resistance than silica and magnesite refractories.
C. Are resistant to basic slag
D. All A., B. and C.

A. Zircon
B. Thoria
C. Carborundum
D. Beryllia

A. Silica bricks
B. Fireclay bricks
C. Both A. & B.
D. Neither A. nor B.

A. Thermal insulation
B. Transformers
C. Magnetic switches
D. Television sets

A. Dehydrate the dried refractory
B. Develop stable mineral forms in them
C. Form ceramic bonds necessary for development of high crushing strength in the finished
product
D. All A., B. and C.

A. crack when subjected to sudden change of temperature
B. Cannot be used in the dome of hot blast stoves
C. Have lower thermal conductivity than fireclay bricks
D. All A., B. and C.

A. Chrome magnesite
B. Magnesite
C. Dolomite
D. Silicon carbide

A. Firebrick
B. Sillimanite
C. Magnesite
D. Aluminous firebrick

A. Chemical composition
B. Physical structure
C. Presence of impurities like iron & alkali
D. All A., B. and C.