3314. Alumina-graphite bricks are used for lining the
slide gate in teeming laddies.
continuous casting systems.
both (a) and (b).
neither (a) nor (b).
✅ The correct answer is option C.
3319. Bomb calorimeter can be used to determine the __________ of the coal.
Sulphur content
Calorific value
Both A & B
Neither A nor B
✅ The correct answer is option C.
3323. Calorific value as determined by bomb calorimeter is the
Higher calorific value at constant volume
Gross calorific value at constant pressure
Lower calorific value at constant pressure
Net calorific value at constant volume
✅ The correct answer is option A.
3327. Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to
thermal spalling
slag attack
fusion under load
CO attack
✅ The correct answer is option A.
3331. In high temperature carbonisation (as compared to low temperature carbonisation) of coal
Coke oven gas yield is more
Tar yield is less but free carbon in tar is more
Calorific value of coke oven gas is less
All of the above
✅ The correct answer is option D.
3260. Water content in ground refractory material to be shaped into bricks by hand moulding is about __________ percent.
5
20
40
55
✅ The correct answer is option B.
3265. Kopper-Totzek coal gasifier (installed in a coal based nitrogeneous fertiliser plant) employs a/an __________ bed gasifier.
Entrained
Moving
Fixed
Fluidised
✅ The correct answer is option A.
3269. Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
770
570
270
70
✅ The correct answer is option C.
3274. Steam is intermittently admitted into the fuel bed during the production of producer gas to
Convert CO to CO₂
Increase the combustion rate
Increase the gas production rate
Minimise the chances of clinker formation
✅ The correct answer is option D.
3279. Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
segar cones.
muffles for muffle furnaces.
insulating bricks.
crucibles used for melting of high purity metals.
✅ The correct answer is option D.