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