Chrome magnesite is not used in the ____________________?

A. Inner lining of L.D. converter
B. Aluminium melting furnaces
C. Wear out lining of steel melting furnaces
D. All A., and B. and C.

______________ bricks are used in the burning zone of a cement rotary kiln ?

A. High alumina
B. Fireclay
C. Thoria
D. Silicon carbide

Maximum water percentage in refractory mix meant for hand moulding may be as high as _____________ percent?

A. 2-3
B. 5-7
C. 7-12
D. 14-20

Which of the following has the lowest electrical resistivity ?

A. Graphite
B. Fireclay
C. Alumina
D. Zircon

Refractory castables are used for__________________?

A. Producing monolithic linings
B. Patch work
C. Minimising the number of joints in the structure
D. All A., B. and C.

Silicon carbide refractories have very low ___________________?

A. Refractoriness (< 1700°C)
B. Thermal conductivity
C. Resistance to thermal shock
D. None of these

Carbon refractories are exclusively used in the_________________?

A. Hearth of blast furnace
B. Walls of coke oven
C. Regenerators of coke oven
D. Side wall of soaking pits

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 ?

A. 1800
B. 2200
C. 2400
D. 2700

Which is the most stable crystalline form of silica at room temperature ?

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

Which of the following bricks has the most close values of RUL and PCE ?

A. Silica bricks
B. Fireclay bricks
C. High alumina bricks
D. Tar dolomite bricks