Refractory Technology MCQs

Question 1

High refractorinness of refractory bricks means, that it has a

Accepted Answer

High resistance to fusion

Answer

High spalling resistance

Answer

Low spalling resistance

Answer

Low porosity

Question 2

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

Accepted Answer

Cristobalite

Answer

Tridymite

Answer

Quartz

Answer

None of these

Question 3

Crushing strength of a refractory

Accepted Answer

Decreases with rise in service temperature

Answer

Increases with rise in service temperature

Answer

Is unaffected with change in service temperature

Answer

Decreases with increase in porosity

Question 4

Panel test determines the __________ of refractories.

Accepted Answer

Spalling resistance

Answer

Fusion point

Answer

Slag penetration resistance

Answer

Refractoriness under load (RUL)

Question 5

Semi-silica bricks compared to silica bricks have

Accepted Answer

Both A & B

Answer

Less fusion point

Answer

Better spalling resistance

Answer

Neither A nor B

Question 6

Cold crushing strength of refractories depends upon its

Accepted Answer

All of the above

Answer

Composition

Answer

Texture

Answer

Firing temperature

Question 7

Carbon refractories have very high

Accepted Answer

Both B and C

Answer

Wetting characteristics

Answer

Refractoriness

Answer

Thermal conductivity

Question 8

Chromite refractories are used in

Accepted Answer

Both A & B

Answer

Bottom of soaking pits

Answer

Between acid & basic linings in basic open hearth furnaces to prevent their chemical action with each other

Answer

Neither A nor B

Question 9

Pick out the wrong statement.

Accepted Answer

Superduty fireclay bricks correspond to a pyrometric cone equivalent of 26-28

Answer

Insulating refractories used in place of regular refractory bricks are usually called light weight refractories, and they have similar composition as heavy bricks

Answer

Graphite refractories are also called plumbago refractories

Answer

Calcined magnesite is also called dead burnt magnesite