Porosity
RUL
Specific gravity
Thermal conductivity
✅ The correct answer is option B.
Refractory Technology MCQs
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
spalling resistance.
refractoriness.
refractoriness under load (RUL).
none of these.
✅ The correct answer is option A.
Magnesite refractories are generally not used in the
electric furnace walls.
steel melting furnace.
open hearth furnace.
burning zone of cement kilns.
✅ The correct answer is option B.
Spalling resistance of a refractory can not be increased by
increasing its porosity.
using a coarser grog during its manufacture.
decreasing its thermal co-efficient of expansion.
making it denser.
✅ The correct answer is option D.
Silica refractories are not used in
coke oven walls.
beehive coke ovens.
dome and upper portion of B.F. stoves.
open hearth furnace roof.
✅ The correct answer is option B.
Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns.
1800
2200
2400
2700
✅ The correct answer is option D.
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
chrome or magnesite
silicon carbide
silica
lowduty fireclay
✅ The correct answer is option A.
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm2 ) is __________ °C.
500
1000
>1350
>2000
✅ The correct answer is option C.
An indication of degree of firing in silica brick is its
specific gravity
fusion point
RUL
none of these
✅ The correct answer is option A.
Roof of a basic open hearth furnace is lined with __________ bricks.
silica
fireclay
dolomite
magnesite
✅ The correct answer is option A.