REFRACTORY TECHNOLOGY QUIZ

Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?

Water

Lime

Aluminium phosphate

Plaster of paris

TRUE ANSWER : ?
YOUR ANSWER : ?

High refractorinness of refractory bricks means, that it has a

High spalling resistance

Low spalling resistance

Low porosity

High resistance to fusion

TRUE ANSWER : ?
YOUR ANSWER : ?

Spray test determines the __________ of refractories.

Resistance to slag penetration

Permanent linear change

RUL

Resistance to CO attack

TRUE ANSWER : ?
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Silica refractories

All of these

Can not be used in the dome of hot blast stoves

Crack when subjected to sudden change of temperature

Have lower thermal conductivity than fireclay bricks

TRUE ANSWER : ?
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Test piece for determination of RUL of a refractory is heated in a/an

Reducing atmosphere

Oxidising atmosphere

Neutral atmosphere

Electric furnace

TRUE ANSWER : ?
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Porosity of silica bricks varies from __________ percent.

20 to 30

60 to 75

5 to 10

45 to 60

TRUE ANSWER : ?
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__________ is not a single oxiderefractory.

Silicon carbide

Magnesia

None of these

Zirconia

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To resist spalling tendency, a refractory should have

All of these

Low specific heat

Greater diffusivity

Low thermal co-efficient of expansion

TRUE ANSWER : ?
YOUR ANSWER : ?

Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.

70

270

570

770

TRUE ANSWER : ?
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Which is not a high alumina refractory?

Mullite

Dolomite

Bauxite

Corrundum

TRUE ANSWER : ?
YOUR ANSWER : ?

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