Refractory Technology MCQs

stable form of silica upto 870°C.

converted to tridymite on firing between 870 to 1470°C.

transformed to crystoballite on heating above 1470°C.

all (a), (b) and (c).

silica bricks

low duty firebricks

high alumina bricks

graphite blocks

crushing strength

resistance to slag attack

both (a) and (b)

neither (a) nor (b)

fireclay

silica

dolomite

very low alumina

making sheaths for thermocouple.

lining high temperature ceramic kilns.

furnaces subjected to fluctuating temperature.

high frequency induction furnaces in the form of inductors.

producing monolithic linings.

patch work.

minimising the number of joints in the structure.

all (a), (b) and (c).

very high temperatures are involved.

highly reducing conditions are involved.

presence of iron or silica is harmful.

all (a), (b) and (c).

Firebrick

Sillimanite

Semi-silica

Aluminous firebrick

inner lining of L.D. converter.

aluminium melting furnaces.

wear out lining of steel melting furnaces.

all (a), and (b) and (c)

superduty fireclay

silica

chromite

none of these