3364. Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
55
70
80
90
✅ The correct answer is option D.
3369. Which is not a basic refractory ?
Chrome magnesite
Magnesite
Dolomite
Silicon carbide
✅ The correct answer is option D.
3336. Fusion temperature of pure silica (SiO2) is __________ °C.
1350
1715
2570
2800
✅ The correct answer is option B.
3342. Conversion of silica mineral to cristobalite is accompanied by reduction in its
volume
specific gravity
both (a) & (b)
neither (a) nor (b)
✅ The correct answer is option B.
3346. Cold crushing strength of refractories depends upon its
composition
texture
firing temperature
all (a), (b) and (c)
✅ The correct answer is option D.
3350. Maximum safe working temperature for fireclay bricks is about __________ °C.
1150
1300
1450
1550
✅ The correct answer is option D.
3351. Porosity of fireclay refractories is __________ percent.
5-Oct
Oct-25
25-35
35-50
✅ The correct answer is option B.
3355. Firing of refractory brick is done to
dehydrate the dried refractory.
develop stable mineral forms in them.
form ceramic bonds necessary for development of high crushing strength in the finished product.
all (a), (b) and (c).
✅ The correct answer is option D.
3360. Which brick undergoes maximum shrinkage on drying ?
Tar bonded dolomite bricks
Fireclay bricks
Magnesite bricks
Chromite bricks
✅ The correct answer is option B.
3365. A steel member used in the furnace construction to take the thrust of the brickwork is called
buckstay
breast wall
armouring
baffle
✅ The correct answer is option A.