Refractory Technology MCQs

212 MCQs  — Chemical Engineering MCQs  (Page 8 of 22)

Insulating refractories should have_______________?
A. High porosity
B. Low thermal conductivity
C. Both a. and b.
D. Neither a. not b.
Which is the stable form of silica below 870°C ?
A. Tridymite
B. Cristobalite
C. Quartz
D. None of these
Which of the following is not a neutral refractory ?
A. Silicon carbide
B. Magnesite
C. Chromite
D. Graphite
Electrical resistor bars are made of _______________?
A. Silicon carbide
B. Alumina
C. Zirconia
D. Graphite
Refractories are dried in the _______________?
A. Rotary kilns
B. Tunnel kilns
C. Sun
D. None of these
Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage ?
A. Tar bonded dolomite bricks
B. Fireclay bricks
C. Mullite bricks
D. Magnesite bricks
Which is not an alumino-silicate refractory ?
A. Fireclay bricks
B. Mullite bricks
C. Tar dolomite bricks
D. High alumina bricks
Resistance to slag attack of a refractory _____________________?
A. Depends on the nature of slag & refractory
B. Decreases at higher temperature
C. Decreases, if defective joints & cracks exist in the refractory
D. All a., b. and c.