Refractory materials are never used in the construction of
Refractory materials are never used in the construction of
Spalling of a refractory means its
Spalling of a refractory means its
Which of the following bricks should not be used, if the furnace is to be used intermit-tantly?
Which of the following bricks should not be used, if the furnace is to be used intermit-tantly?
Use of higher percentage of lime for bonding silica bricks, reduces their
Use of higher percentage of lime for bonding silica bricks, reduces their
With increase in the alumina content, the refractoriness of high alumina refractories
With increase in the alumina content, the refractoriness of high alumina refractories
Carbon refractories have very high
Carbon refractories have very high
Dilatometer is used for the determination of __________ of refractories.
Dilatometer is used for the determination of __________ of refractories.
Spray test determines the __________ of refractories.
Spray test determines the __________ of refractories.
Bottom of basic open hearth furnace are constructed of
Bottom of basic open hearth furnace are constructed of
Natural silica
Natural silica
Pure oxide refractories are generally monocrystaliine in nature and are self bonded __________ bricks are generally used as moderator in nuclear reactors.
Pure oxide refractories are generally monocrystaliine in nature and are self bonded __________ bricks are generally used as moderator in nuclear reactors.
RUL of refractories depends on the
RUL of refractories depends on the
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.
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.
silicon carbide refractories have very low
silicon carbide refractories have very low
Fireclay bricks are not used in the
Fireclay bricks are not used in the
Graphite or carbon refractories
Graphite or carbon refractories
Fireclay bricks are not used in the
Fireclay bricks are not used in the
Ferromagnetic ceramic material is not used in the
Ferromagnetic ceramic material is not used in the
Grog addition in fireclay during brick manufacture is done to
Grog addition in fireclay during brick manufacture is done to
'Spinel', a refractory mineral is chemically represented as
'Spinel', a refractory mineral is chemically represented as
Which one contains minimum percentage of SiO₂?
Which one contains minimum percentage of SiO₂?
High alumina refractory compared to fireclay bricks have
High alumina refractory compared to fireclay bricks have
Refractories are dried in the
Refractories are dried in the
Addition of grog in fireclay brick during its manufacture is advantageous, because it results in
Addition of grog in fireclay brick during its manufacture is advantageous, because it results in
Which is not a high alumina refractory?
Which is not a high alumina refractory?
SiO₂ percentage in firebrick is about
SiO₂ percentage in firebrick is about
Which furnace consumes maximum refractory annually in an integrated steel plant?
Which furnace consumes maximum refractory annually in an integrated steel plant?
The maximum linear expansion of silica bricks during firing is about __________ percent.
The maximum linear expansion of silica bricks during firing is about __________ percent.
Which is a neutral refractory?
Which is a neutral refractory?
Sillimanite is a __________ refractory.
Sillimanite is a __________ refractory.
Pick out the wrong statement.
Pick out the wrong statement.
Which form of silica has the highest specific gravity?
Which form of silica has the highest specific gravity?
Tar dolomite bricks are used in the
Tar dolomite bricks are used in the
Periclase is
Periclase is
Chrome magnesite is not used in the
Chrome magnesite is not used in the
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
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
Refractory bricks with lower permeability is produced by using
Chrome magnesite brick is not used for lining the
Chrome magnesite brick is not used for lining the
Which of the following does not occur during firing/burning of refractories?
Which of the following does not occur during firing/burning of refractories?
High refractorinness of refractory bricks means, that it has a
High refractorinness of refractory bricks means, that it has a
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Spalling tendency of refractories is reduced by increasing its
Spalling tendency of refractories is reduced by increasing its
Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant?
Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant?
Tar bonded dolomite bricks
Tar bonded dolomite bricks
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage?
Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage?
Which is the most stable crystalline form of silica at room temperature?
Which is the most stable crystalline form of silica at room temperature?
Pick out the wrong statement.
Pick out the wrong statement.
Magnesite chrome refractories
Magnesite chrome refractories
Silliminite (Al2O₃.SiO₂) refractory, which is a neutral refractory, is not used in
Silliminite (Al2O₃.SiO₂) refractory, which is a neutral refractory, is not used in
Fusion temperature of pure silica (SiO₂) is __________ °C.
Fusion temperature of pure silica (SiO₂) is __________ °C.
Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to
Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to
Carbon refractories are exclusively used in the
Carbon refractories are exclusively used in the
Ramming masses are used for
Ramming masses are used for
Magnesite bricks are used in those parts of furnaces, which are
Magnesite bricks are used in those parts of furnaces, which are
Silica bricks have low spalling resistance below 600°C, due to its
Silica bricks have low spalling resistance below 600°C, due to its
High porosity refractory bricks have
High porosity refractory bricks have
Ganister is a source of the
Ganister is a source of the
Electrical resistor bars are made of
Electrical resistor bars are made of
Magnesite refractories are used for the construction of those furnaces, which are
Magnesite refractories are used for the construction of those furnaces, which are
Chromite refractories are used in
Chromite refractories are used in
Pyrometric cone equivalent (PCE) of a refractory is the measure of its
Pyrometric cone equivalent (PCE) of a refractory is the measure of its
Firing of refractory brick is done to
Firing of refractory brick is done to
'Super refractories' are made from pure
'Super refractories' are made from pure
Silicon carbide refractories are used in the
Silicon carbide refractories are used in the
Which of the following has the lowest electrical resistivity?
Which of the following has the lowest electrical resistivity?
Chrome magnesite bricks are used in the
Chrome magnesite bricks are used in the
Refractory castables are used for
Refractory castables are used for
__________ nozzles are used in continuous casting of steel,
__________ nozzles are used in continuous casting of steel,
Dolomite bricks have good resistance to attack by
Dolomite bricks have good resistance to attack by
Segar cones are used for the determination of __________ of refractories.
Segar cones are used for the determination of __________ of refractories.
With decrease in porosity, the __________ of the refractories decreases.
With decrease in porosity, the __________ of the refractories decreases.
The linear thermal expansion of __________ bricks upto 1000 °C is very low of the order of ≤ 0.5 percent.
The linear thermal expansion of __________ bricks upto 1000 °C is very low of the order of ≤ 0.5 percent.
To resist spalling tendency, a refractory should have
To resist spalling tendency, a refractory should have
Carborundum used for making crucibles for melting non-ferrous metals is chemically
Carborundum used for making crucibles for melting non-ferrous metals is chemically
Machine moulding of dry mixture of refractories requires a pressure of the order of __________ kg/cm².
Machine moulding of dry mixture of refractories requires a pressure of the order of __________ kg/cm².
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?
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?
Pick out the wrong statement.
Pick out the wrong statement.
Maximum apparent porosity of magnesite bricks is about __________ percent.
Maximum apparent porosity of magnesite bricks is about __________ percent.
The highest melting pure oxide (m.p. > 3000°C) is
The highest melting pure oxide (m.p. > 3000°C) is
Skull is not formed on the carbon blocks in the hearth of a blast furnace, when it becomes cold, becaus of its
Skull is not formed on the carbon blocks in the hearth of a blast furnace, when it becomes cold, becaus of its
Mullite is chemically represented by
Mullite is chemically represented by
Cold crushing strength of fireclay bricks is about __________ kgf/cm².
Cold crushing strength of fireclay bricks is about __________ kgf/cm².
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm² ) is __________ °C.
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm² ) is __________ °C.
Rate of slag attack on refractories increases with rise in temperature due to the
Rate of slag attack on refractories increases with rise in temperature due to the
Which is an acidic refractory?
Which is an acidic refractory?
Fireclay bricks are used in the
Fireclay bricks are used in the
Fireclay refractories have
Fireclay refractories have
Fireclay refractories
Fireclay refractories
With increase in the porosity, thermal spalling resistance of fireclay brick
With increase in the porosity, thermal spalling resistance of fireclay brick
Pick out the wrong statement.
Pick out the wrong statement.
The largest consumer of refractories is the __________ industry.
The largest consumer of refractories is the __________ industry.
Which is not an alumino-silicate refractory?
Which is not an alumino-silicate refractory?
Faster rate of drying of moulded refractories results in high __________ of refractories.
Faster rate of drying of moulded refractories results in high __________ of refractories.
Si percentage in silica refractories used in the walls of coke oven is about
Si percentage in silica refractories used in the walls of coke oven is about
Panel test determines the __________ of refractories.
Panel test determines the __________ of refractories.
Silica refractories
Silica refractories
Refractoriness under load (RUL) is the most important property for the refractory bricks
Refractoriness under load (RUL) is the most important property for the refractory bricks
__________ of carbon blocks in the hearth of blast furnace helps in avoiding skull formation, when it becomes cold.
__________ of carbon blocks in the hearth of blast furnace helps in avoiding skull formation, when it becomes cold.
Refractories used in/for __________ should have low thermal conductivity.
Refractories used in/for __________ should have low thermal conductivity.
The main raw material for manufacture of silicon carbide refractories is
The main raw material for manufacture of silicon carbide refractories is
With increasing alumina content, the fusion point of high alumina refractories
With increasing alumina content, the fusion point of high alumina refractories
Pick out the wrong statement.
Pick out the wrong statement.
Crushing strength of a refractory
Crushing strength of a refractory
