New Latest Chemical Engineering MCQs – Refractory Technology MCQs

New Latest Chemical Engineering MCQs – Refractory Technology MCQs

This post is comprising of latest ” Refractory Technology MCQs – Latest Competitive Chemical Engineering MCQs “. Here you’ll get latest mechanical engineering mcqs for written test, interview with answers. If you want to improve your knowledge regarding mechanical engineering then read these mcqs of Design of Steel Structures.

Latest Chemical Engineering MCQs

By practicing these MCQs of Refractory Technology MCQs – Latest Competitive Chemical Engineering MCQs , an individual for exams performs better than before. This post comprising of mechanical engineering objective questions and answers related to Refractory Technology Mcqs “. As wise people believe “Perfect Practice make a Man Perfect”. It is therefore practice these mcqs of mechanical engineering to approach the success. Tab this page to check “Refractory Technology Mcqs” for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others.

Latest Refractory Technology Mcqs

The most occurred mcqs of Refractory Technology in past papers. Past papers of Refractory Technology Mcqs. Past papers of Refractory Technology Mcqs . Mcqs are the necessary part of any competitive / job related exams. The Mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Refractory Technology Mcqs. The Important series of Refractory Technology Mcqs are given below:

With increase in the alumina content, the refractoriness of high alumina refractories_______________?

A. Increases
B. Remain same
C. Decreases
D. May increase or decrease

Test piece for determination of RUL of a refractory is heated in a/an____________________?

A. Reducing atmosphere
B. Oxidising atmosphere
C. Electric furnace
D. Neutral atmosphere

Magnesite refractories are used for the construction of those furnaces, which are________________?

A. Not required to resist the corrosive action of basic slag
B. Used for raising & maintaining high temperature
C. Not subjected to fluctuation in temperature
D. Both B. and C.

Outer combustion chamber of blast furnace stove is lined with _____________ bricks?

A. Fireclay
B. Chrome magnesite
C. Silica
D. Zirconia

Roof of a basic electric furnace is made of _____________ bricks?

A. Chromite
B. Silica
C. Superduty fireclay
D. None of these

Faster rate of drying of moulded refractories results in high _____________ of refractories?

A. Green strength
B. Shrinkage
C. Voids
D. Both B. and C.

What is the value of ‘q’ for saturated liquid feed to a distillation column ?

A. 0
B. >1
C. 1
D. <1

Silica refractories are not used in _________________?

A. Open hearth furnace roof
B. Beehive coke ovens
C. Dome and upper portion of B.F. stoves
D. Coke oven walls

Porosity of silica bricks varies from ______________ percent?

A. 45 to 60
B. 20 to 30
C. 5 to 10
D. 60 to 75

Alumina-graphite bricks are used for lining the ____________________?

A. Continuous casting systems
B. Slide gate in teeming laddies
C. Both A. and B.
D. Neither A. nor B.

The main raw material for manufacture of silicon carbide refractories is_________________?

A. Bauxite
B. Carborundum
C. Corundum
D. Periclase

Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the_________________?

A. Washing action of metal
B. Corrosion by layer of slag
C. Both of the above
D. Neither of the above

High density refractory bricks have lower__________________?

A. Spalling resistance
B. Fusion point
C. Thermal conductivity
D. Slag penetration resistance

Fireclay bricks are used in the___________________?

A. Furnaces allowed to cool frequently
B. Chimney linings
C. Flues
D. All A., B. and C.

Carbon refractory blocks ___________________?

A. Are acidic in nature
B. Are used in the hearth of blast furnace
C. Are wetted by molten iron
D. All A., B. and C.

Chromite refractories are used in_______________?

A. Between acid & basic linings in basic open hearth furnaces to prevent their chemical action with each other
B. Bottom of soaking pits
C. Both A. & B.
D. Neither A. and B.

Maximum apparent porosity of magnesite bricks is about _____________ percent?

A. 44
B. 24
C. 8
D. 58

Cold crushing strength of refractories depends upon its_________________?

A. Texture
B. Composition
C. Firing temperature
D. All A., B. and C.

Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves ?

A. High refractoriness
B. High strength and density
C. High resistance to spalling
D. All A., B. and C.

Spalling resistance of a refractory cannot be increased by ____________________?

A. Decreasing its thermal co-efficient of expansion
B. Using a coarser grog during its manufacture
C. Increasing its porosity
D. Making it denser

High refractoriness of refractory bricks means, that it has a________________?

A. Low spalling resistance
B. High spalling resistance
C. High resistance to fusion
D. Low porosity

To resist spalling tendency, a refractory should have________________?

A. Low specific heat
B. Greater diffusivity
C. Low thermal co-efficient of expansion
D. All A., B. and C.

Cermets are____________________?

A. Composite material containing both ceramic & metallic constituents
B. Used in space vehicles, missiles & nuclear energy plants
C. Having high strength & resistance to high temperature
D. All A., B. and C.

Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory_________________?

A. Cements
B. Mortars
C. Castables
D. None of these

Hot face insulating linings of high purity alumina fused mullite are used, where_________________?

A. Presence of iron or silica is harmful
B. Highly reducing conditions are involved
C. Very high temperatures are involved
D. All A., B. and C.

Periclase refractory contains mainly________________?

A. Al2O3
B. MgO
C. CaO
D. SiO2

Refractory Technology Mcqs

Silica bricks have low spalling resistance below 600°C, due to its________________?

A. High thermal diffusivity
B. High co-efficient of expansion upto this temperature
C. Very high thermal conductivity
D. Low refractoriness

Magnesite refractories have low resistance to___________________?

A. Attack by basic slag
B. Disintegration on sudden change of temperature
C. Abrasion
D. Both B. and C.

Which is a basic refractory ?

A. Silica
B. Fireclay
C. Chrome magnesite
D. None of these

Tar dolomite bricks are used in the_________________?

A. Basic Bessemer converter
B. Electric furnaces
C. Basic open hearth furnace
D. All A., B. and C.

Cold crushing strength of fireclay bricks is about ______________ kgf/cm2?

A. 100-150
B. 50-100
C. 200-400
D. 500-1000

Sillimanite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in________________?

A. Pottery furnace
B. Crucibles
C. Glass melting furnace
D. Gas retorts

Rate of slag attack on refractories increases with rise in temperature due to the___________________?

A. Decreased viscosity of slag
B. Oxidising condition in the furnace
C. Increased thermal conductivity of brick
D. None of these

Tar bonded dolomite bricks__________________?

A. Are stored under controlled temperature & humidity to avoid hydration
B. Have poorer hydration resistance than pitch bonded bricks
C. Are used in outer lining of L.D. converters
D. All A., B. and C.

Which furnace consumes maximum refractory annually in an integrated steel plant ?

A. Blast furnace
B. Soaking pit
C. L.D. converter
D. Coke ovens

Which of the following bricks should not be used, if the furnace is to be used intermittently ?

A. Sillimanite
B. Silica bricks
C. Silicon carbide bricks
D. Firebricks

Refractoriness under load (RUL) is the most important property for the refractory bricks_________________?

A. At the hearth bottom of the furnace on which stock is placed
B. Used in the roof of the furnace
C. Used for furnace insulation
D. None of these

Ganister is a source of the ________________?

A. Silica
B. Lime
C. Periclase
D. None of these

Which is required in an insulating refractory ?

A. Low porosity
B. High thermal conductivity
C. Both A. and B.
D. Neither A. nor B.

Sillimanite is a _____________ refractory?

A. Neutral
B. Basic
C. High alumina
D. Insulating

Carbon refractories_____________________?

A. Do not resist temperature fluctuations
B. Are not attacked by slags, as they are not wetted by melts
C. Do not burn/oxidise, when exposed to air on heating
D. Have extremely low thermal & electrical conductivities

Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm2) is ______________ °C?

A. 1000
B. 500
C. >1350
D. >2000

Natural silica___________________?

A. Is not stable at high temperature
B. Mainly contains quartz
C. Transforms to other allotropic forms i.e. Tridymite and Cristobalite involving very high volume changes
D. All A., B. and C.

Spalling tendency of refractories is reduced by increasing its_________________?

A. Porosity
B. Strength
C. Thermal conductivity
D. Specific gravity

Which is not a high alumina refractory ?

A. Corundum
B. Mullite
C. Bauxite
D. Dolomite

Which brick undergoes maximum shrinkage on drying ?

A. Magnesite bricks
B. Fireclay bricks
C. Tar bonded dolomite bricks
D. Chromite bricks

10 to 30% magnesite is added to Chromite to produce chrome-magnesite refractories. Magnesite addition is mainly done to improve the _____________ of Chromite?

A. Spalling resistance
B. Crushing strength
C. Refractoriness
D. Resistance to slag

Furnace atmosphere for softening temperature determination of refractories (in which Seger Cones are placed) should be __________________?

A. Neutral
B. Oxidising
C. Either A. or B.
D. Neither A. nor B.

Ramming masses are used for____________________?

A. Repairing construction of various furnace parts
B. Obtaining monolithic working faces
C. Both A. & B.
D. Neither A. nor B.

Thermodynamics Mcqs

Pyrometric cone equivalent (PCE) of a refractory is the measure of its_________________?

A. Resistance to slag penetration
B. Fusion point
C. Spalling resistance
D. Resistance to carbon monoxide attack

Addition of grog in fireclay brick during its manufacture is advantageous, because it results in_____________________?

A. High strength & thermal spalling resistance
B. Less shrinkage in heating, decreased apparent porosity & increased specific gravity
C. Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production
D. All A., B. and C.

Use of higher percentage of lime for bonding silica bricks, reduces their__________________?

A. Abrasion resistance
B. Strength
C. Both A. & B.
D. Neither A. nor B.

Magnesite chrome refractories____________________?

A. Have better spalling resistance than chrome magnesite refractories
B. Are not at all resistant to the corrosive action of iron oxide
C. Have very low thermal co-efficient of expansion
D. Have very low (50 kg/cm2) cold crushing strength (C.C.S.), and cannot be used in metalcase form

‘Super refractories’ are made from pure____________________?

A. Borides
B. Oxides
C. Carbides
D. Nitrides

Skull is not formed on the carbon blocks in the hearth of a blast furnace, when it becomes cold, because of its_______________?

A. Non-wetting characteristic
B. High crushing strength
C. High thermal conductivity
D. None of these

Maximum safe working temperature for fireclay bricks is about __________ °C?

A. 1300
B. 1150
C. 1450
D. 1550

Which is the stable form of silica between 1470°C and the melting point 1713°C ?

A. Cristobalite
B. Quartz
C. Tridymite
D. None of these

Cold crushing strength of a refractory does not depend upon its ____________________?

A. Shape
B. Firing temperature
C. Composition
D. Texture

Thoria__________________?

A. Has high resistance to basic slags
B. Has high fusion temperature (> 3000°C) but poor resistance to thermal shock
C. Which is expensive & radioactive, is used in crucibles for melting high purity metals
D. All A., B. and C.

Chromite refractories are_____________________?

A. Basic refractory
B. Neutral refractory
C. Acidic refractory
D. Fired at a temperature of 600°C only

Vacuum steel degassing units are lined with__________________?

A. Low duty firebricks
B. Silica bricks
C. High alumina bricks
D. Graphite blocks

With increasing alumina content, the fusion point of high alumina refractories__________________?

A. Increases
B. Remain constant
C. Decreases
D. May increase or decrease; depends on its alumina content

Walls, roofs & combustion chambers of annealing furnaces are made of ______________ bricks?

A. High duty fireclay
B. Mullite
C. Silica
D. Carborundum

Cold crushing strength of ordinary fireclay brick is about 950 kg/cm2. On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as ______________ kg/cm2?

A. 250
B. 450
C. 150
D. 65

Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of______________?

A. Insulating bricks
B. Muffles for muffle furnaces
C. Segar cones
D. Crucibles used for melting of high purity metals

PCE value (Segar cone) of Superduty refractories is more than 33, which is equivalent to a temperature of ____________ °C?

A. 1630
B. 1520
C. 1670
D. 1730

Spray test determines the _____________ of refractories?

A. Resistance to slag penetration
B. RUL
C. Resistance to CO attack
D. Permanent linear change

Fireclay refractories have __________________?

A. Low co-efficient of thermal expansion
B. Very high cost
C. Tendency to expand unduly high during firing
D. Poor thermal spalling resistance

Dolomite bricks have good resistance to attack by_____________________?

A. Molten steel
B. Lime slag
C. Iron oxide
D. None of these

Zirconia refractories are not used in_____________________?

A. Lining high temperature ceramic kilns
B. Making sheaths for thermocouple
C. Furnaces subjected to fluctuating temperature
D. High frequency induction furnaces in the form of inductors

The highest melting pure oxide (m.p. > 3000°C)is___________________?

A. Thoria
B. Beryllia
C. Alumina
D. Zirconia

The largest consumer of refractories is the _______________ industry?

A. Fertiliser
B. Metallurgical
C. Cement
D. Power

Crushing strength of a refractory____________________?

A. Decreases with increase in porosity
B. Decreases with rise in service temperature
C. Is unaffected with change in service temperature
D. Increases with rise in service temperature

Colour of fireclay bricks is_________________?

A. Light buff to reddish buff
B. Black
C. Yellow
D. None of these

Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with _____________ bricks?

A. Bakelite impregnated or fused periclase
B. Semi-silica
C. Silica
D. Fireclay

Highest melting (m.p = 3070°C) oxide refractory is__________________?

A. Zirconia
B. Thoria
C. Alumina
D. Magnesia

Dilatometer is used for the determination of ______________ of refractories?

A. RUL
B. Permanent linear change
C. Resistance to CO attack
D. Modulus of rupture

Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for _____________ bricks?

A. Dolomite
B. Silica
C. Fireclay
D. Very low alumina

The maximum linear expansion of silica bricks during firing is about ______________ percent?

A. 1
B. 0.5
C. 2
D. 3.5

Hot blast main (carrying air at 1000°C) in blast furnace are lined with ______________ bricks?

A. Magnesite
B. Fireclay
C. Silica
D. Zirconia

With decrease in porosity, the ______________ of the refractories decreases?

A. Thermal conductivity
B. Strength
C. Spalling resistance
D. None of these

Process Control And Instrumentation

______________ bricks should not be used in oxidising atmosphere?

A. Silica
B. Carbon
C. Tar dolomite
D. Fireclay

Magnesite bricks have poor resistance to attack by _____________ slag?

A. Basic
B. Lime
C. Acid
D. None of these

Which is not a natural insulating material ?

A. Asbestos
B. Diatomaceous earth/kieselgur
C. Vermiculite
D. None of these

Which of the following is not a high alumina refractory material ?

A. Sillimanite
B. Kyanite
C. Diaspore
D. Periclase

___________________ is the measure of the strength of refractory under the combined effect of temperature & load ?

A. Specific gravity
B. RUL
C. Porosity
D. Thermal conductivity

Which one contains minimum percentage of SiO2 ?

A. Semi-silica
B. Sillimanite
C. Firebrick
D. Aluminous firebrick

Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as _____________ percent?

A. 55
B. 80
C. 70
D. 90

Mullite is chemically represented by_________________?

A. Al2O3. SiO2
B. 3Al2O3. 2SiO2
C. Al2O3. 2SiO2
D. 2Al2O3. 3SiO2

High alumina refractory compared to fireclay bricks have____________________?

A. Low refractoriness
B. Less resistance to slag attack
C. Less load bearing capacity
D. High resistance to thermal shock and creep

Porosity of fireclay refractories is _______________ percent?

A. 25-35
B. 10-25
C. 5-10
D. 35-50

Fusion temperature of pure silica (SiO2) is _______________ °C?

A. 2570
B. 1715
C. 1350
D. 2800

Bottom of basic open hearth furnace are constructed of__________________?

A. Dead burnt magnesite ramming mass
B. Semi-silica bricks
C. Porous fireclay bricks
D. Silicon carbide bricks

Addition of zircon to silica refractory brick improves its_____________________?

A. Crushing strength
B. Resistance to slag attack
C. Both of the above
D. Neither of the above

Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to__________________?

A. Thermal spalling
B. CO attack
C. Fusion under load
D. Slag attack

Refractory bricks with lower permeability is produced by using __________________?

A. Higher moulding pressure
B. Higher firing temperature
C. Finer grog size
D. All A., B. and C.

Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors?

A. Beryllia
B. Corundum
C. Carborundum
D. Thoria

Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of________________?

A. Corundum
B. Silicon carbide
C. Fireclay
D. Siliceous fireclay

Refractory bricks having lower porosity have_________________________?

A. Low heat capacity
B. High insulating properties
C. Low thermal conductivity
D. Greater strength

Silica bricks are never used for lining the____________________?

A. Beehive coke ovens
B. Dome of blast furnace stoves
C. By-product coke ovens
D. Roof of open hearth furnace

New Latest Chemical Engineering MCQs – Refractory Technology MCQs

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