Fireclay refractories
Fireclay refractories
Firing of refractory brick is done to
Firing of refractory brick is done to
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
Grog addition in fireclay during brick manufacture is done to
Grog addition in fireclay during brick manufacture is done to
High alumina refractory compared to fireclay bricks have
High alumina refractory compared to fireclay bricks have
'Spinel', a refractory mineral is chemically represented as
'Spinel', a refractory mineral is chemically represented as
Maximum apparent porosity of magnesite bricks is about __________ percent.
Maximum apparent porosity of magnesite bricks is about __________ percent.
Crushing strength of a refractory
Crushing strength of a refractory
Panel test determines the __________ of refractories.
Panel test determines the __________ of refractories.
Chrome magnesite bricks are used in the
Chrome magnesite bricks are used in the
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
Pyrometric cone equivalent (PCE) of a refractory is the measure of its
Pyrometric cone equivalent (PCE) of a refractory is the measure of its
Tar dolomite bricks are used in the
Tar dolomite bricks are used in the
Cold crushing strength of fireclay bricks is about __________ kgf/cm².
Cold crushing strength of fireclay bricks is about __________ kgf/cm².
Which of the following does not occur during firing/burning of refractories?
Which of the following does not occur during firing/burning of refractories?
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.
Silica refractories
Silica refractories
Sillimanite is a __________ refractory.
Sillimanite is a __________ refractory.
Which form of silica has the highest specific gravity?
Which form of silica has the highest specific gravity?
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
Which is the most stable crystalline form of silica at room temperature?
Which is the most stable crystalline form of silica at room temperature?
High refractorinness of refractory bricks means, that it has a
High refractorinness of refractory bricks means, that it has a
Carbon refractories are exclusively used in the
Carbon refractories are exclusively used in the
Carbon refractories have very high
Carbon refractories have very high
SiO₂ percentage in firebrick is about
SiO₂ percentage in firebrick is about
Magnesite refractories are used for the construction of those furnaces, which are
Magnesite refractories are used for the construction of those furnaces, which are
Which furnace consumes maximum refractory annually in an integrated steel plant?
Which furnace consumes maximum refractory annually in an integrated steel plant?
Mullite is chemically represented by
Mullite is chemically represented by
With increasing alumina content, the fusion point of high alumina refractories
With increasing alumina content, the fusion point of high alumina refractories
The main raw material for manufacture of silicon carbide refractories is
The main raw material for manufacture of silicon carbide refractories is
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
Pick out the wrong statement.
Pick out the wrong statement.
RUL of refractories depends on the
RUL of refractories depends on the
Chrome magnesite is not used in the
Chrome magnesite is not used in the
With increase in the alumina content, the refractoriness of high alumina refractories
With increase in the alumina content, the refractoriness of high alumina refractories
Bottom of basic open hearth furnace are constructed of
Bottom of basic open hearth furnace are constructed of
Graphite or carbon refractories
Graphite or carbon refractories
Dolomite bricks have good resistance to attack by
Dolomite bricks have good resistance to attack by
Periclase is
Periclase is
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?
Spalling tendency of refractories is reduced by increasing its
Spalling tendency of refractories is reduced by increasing its
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
Dilatometer is used for the determination of __________ of refractories.
Dilatometer is used for the determination of __________ of refractories.
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?
Electrical resistor bars are made of
Electrical resistor bars are made of
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.
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
Which is not a high alumina refractory?
Which is not a high alumina refractory?
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.
Natural silica
Natural silica
Fireclay bricks are used in the
Fireclay bricks are used in the
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
Fireclay bricks are not used in the
Fireclay bricks are not used in the
Fireclay refractories have
Fireclay refractories have
Segar cones are used for the determination of __________ of refractories.
Segar cones are used for the determination of __________ of refractories.
Chromite refractories are used in
Chromite refractories are used in
'Super refractories' are made from pure
'Super refractories' are made from pure
Which is an acidic refractory?
Which is an acidic refractory?
Silica bricks have low spalling resistance below 600°C, due to its
Silica bricks have low spalling resistance below 600°C, due to its
Refractories used in/for __________ should have low thermal conductivity.
Refractories used in/for __________ should have low thermal conductivity.
Spalling of a refractory means its
Spalling of a refractory means its
Which of the following has the lowest electrical resistivity?
Which of the following has the lowest electrical resistivity?
High porosity refractory bricks have
High porosity refractory bricks have
Spray test determines the __________ of refractories.
Spray test determines the __________ of refractories.
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?
Use of higher percentage of lime for bonding silica bricks, reduces their
Use of higher percentage of lime for bonding silica bricks, reduces their
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.
Pick out the wrong statement.
Pick out the wrong statement.
Faster rate of drying of moulded refractories results in high __________ of refractories.
Faster rate of drying of moulded refractories results in high __________ of refractories.
Pick out the wrong statement.
Pick out the wrong statement.
silicon carbide refractories have very low
silicon carbide refractories have very low
Carborundum used for making crucibles for melting non-ferrous metals is chemically
Carborundum used for making crucibles for melting non-ferrous metals is chemically
The largest consumer of refractories is the __________ industry.
The largest consumer of refractories is the __________ industry.
__________ 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.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Fireclay bricks are not used in the
Fireclay bricks are not used in the
Ganister is a source of the
Ganister is a source of the
Magnesite chrome refractories
Magnesite chrome refractories
With decrease in porosity, the __________ of the refractories decreases.
With decrease in porosity, the __________ of the refractories decreases.
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.
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
To resist spalling tendency, a refractory should have
To resist spalling tendency, a refractory should have
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
The maximum linear expansion of silica bricks during firing is about __________ percent.
The maximum linear expansion of silica bricks during firing is about __________ percent.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
Chrome magnesite brick is not used for lining the
Chrome magnesite brick is not used for lining the
Ferromagnetic ceramic material is not used in the
Ferromagnetic ceramic material is not used in the
Which is not an alumino-silicate refractory?
Which is not an alumino-silicate refractory?
With increase in the porosity, thermal spalling resistance of fireclay brick
With increase in the porosity, thermal spalling resistance of fireclay brick
The highest melting pure oxide (m.p. > 3000°C) is
The highest melting pure oxide (m.p. > 3000°C) is
Tar bonded dolomite bricks
Tar bonded dolomite bricks
Which one contains minimum percentage of SiO₂?
Which one contains minimum percentage of SiO₂?
Refractories are dried in the
Refractories are dried in the
Refractory materials are never used in the construction of
Refractory materials are never used in the construction of
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?
Fusion temperature of pure silica (SiO₂) is __________ °C.
Fusion temperature of pure silica (SiO₂) is __________ °C.
Refractory bricks with lower permeability is produced by using
Refractory bricks with lower permeability is produced by using
Refractory castables are used for
Refractory castables are used for
Pick out the wrong statement.
Pick out the wrong statement.
Silicon carbide refractories are used in the
Silicon carbide refractories are used in the
__________ nozzles are used in continuous casting of steel,
__________ nozzles are used in continuous casting of steel,
Which is a neutral refractory?
Which is a neutral refractory?
Pick out the wrong statement.
Pick out the wrong statement.
