Search
.Management Sciences
Category: Refractory Technology
Bottom of basic open hearth furnace are constructed of__________________?
A. Dead burnt magnesite ramming mass
B. Porous fireclay bricks
C. Semi-silica bricks
D. Silicon carbide bricks
Panel test determines the _____________ of refractories?
A. Fusion point
B. Spalling resistance
C. Slag penetration resistance
D. Refractoriness under load (RUL)
Maximum safe working temperature for fireclay bricks is about __________ °C?
A. 1150
B. 1300
C. 1450
D. 1550
Zirconia refractories are not used in_____________________?
A. Making sheaths for thermocouple
B. Lining high temperature ceramic kilns
C. Furnaces subjected to fluctuating temperature
D. High frequency induction furnaces in the form of inductors
Silicon carbide refractories have very low ___________________?
A. Refractoriness (< 1700°C)
B. Thermal conductivity
C. Resistance to thermal shock
D. None of these
. Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm2) is ______________ °C?
A. 500
B. 1000
C. >1350
D. >2000
Which of the following does not occur during firing/burning of refractories ?
A. Removal of water of hydration
B. Vitrification
C. Decrease in crushing strength
D. Development of stable mineral form
High alumina refractory compared to fireclay bricks have____________________?
A. Less load bearing capacity
B. Less resistance to slag attack
C. Low refractoriness
D. High resistance to thermal shock and creep
Porosity is induced in insulating refractories by adding________________?
A. Powdered naphthalene
B. Ammonium chloride/sulphate
C. Calcium phosphate
D. All A., B. and C.
Lower part of hot metal mixer are lined with _____________ bricks?
A. Superduty fireclay
B. High alumina
C. Silica
D. Carborundum
Recent Comments