Description : High rate of heating of coke ovens (A) May damage its walls due to abrupt excessive swelling of coal (B) Produces larger size coke (C) Increases the time of carbonisation (D) None of these
Last Answer : (A) May damage its walls due to abrupt excessive swelling of coal
Description : Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these
Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls
Description : Narrow coke ovens as compared to wider coke ovens (A) Produce smaller coke (B) Produce stronger coke (C) Require less time of carbonisation (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Preheating of coal charge for the coke ovens reduces the (A) Time of carbonisation (B) Yield of gas and tar (C) Fuel consumption in coking (D) All (A), (B) and (C)
Description : Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm3 . (A) 30 (B) 300 (C) 3,000 (D) 30,000
Last Answer : (B) 300
Description : Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80
Last Answer : (A) 18
Description : Main use of hard coke produced by high temperature carbonisation is in the (A) Iron blast furnace (B) Cupola in foundries (C) Sinter making (D) Domestic ovens
Last Answer : (A) Iron blast furnace
Description : In low temperature carbonisation of coal as compared to high temperature carbonisation __________ produced is less. (A) Difference in gross & net calorific value of the coke oven gas (B) Free carbon content in tar (C) Yield percentage of coke (D) Yield of ammonia present in coke oven gas
Last Answer : (A) Difference in gross & net calorific value of the coke oven gas
Description : Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal. (A) 60 (B) 160 (C) 500 (D) 750
Last Answer : (B) 160
Description : Calorific value of coke even gas produced by low temperature carbonisation of coal is about __________ Kcal/Nm3 . (A) 4000 (B) 2500 (C) 6500 (D) 10000
Last Answer : (C) 6500
Description : The main product of high temperature carbonisation of coal is (A) Coke (B) Ammonia (C) Tar (D) Coke oven gas
Last Answer : (A) Coke
Description : In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the (A) Gas yield is less (B) Tar yield is more (C) Ignition temperature of coke produced is less (D) Aromatic content of tar produced is more
Last Answer : (D) Aromatic content of tar produced is more
Description : In high temperature carbonisation (as compared to low temperature carbonisation) of coal (A) Coke oven gas yield is more (B) Tar yield is less but free carbon in tar is more (C) Calorific value of coke oven gas is less (D) All (A), (B) and (C)
Description : Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has (A) Higher calorific value (B) Lower hydrogen content (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (D) Neither (A) nor (B)
Description : Blast furnace coke is made from coal by (A) Low temperature carbonisation (B) High temperature carbonisation (C) Medium temperature carbonisation (D) Heating the coal in an oven in presence of air
Last Answer : (B) High temperature carbonisation
Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Large quantity of tar compared to low temperature carbonisation (D) None of these
Last Answer : (D) None of these
Description : In high temperature carbonisation of coal compared to low temperature carbonisation (A) Yield of ammonia is less (B) Aromatic content of tar is low (C) H2 content in the coke oven gas is more (D) Calorific value of the coke oven gas is lower
Last Answer : (C) H2 content in the coke oven gas is more
Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Larger quantity of tar compared to low temperature carbonisation (D) None of these
Description : The main product of high temperature carbonisation of coal is (A) Coke (B) Ammonia (C) Tar (D) Phenol
Description : Beehive coke oven (A) Facilitates by-products recovery (B) Takes 2-3 days for coking of coal but requires no external fuel for heating (C) Gives larger yield of coke (around 85%) as compared to by-product ovens (D) Produces coke with very poor strength
Last Answer : (B) Takes 2-3 days for coking of coal but requires no external fuel for heating
Description : Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent. (A) 3 & 10 (B) 10 & 3 (C) 10 & 20 (D) 15 & 8
Last Answer : (B) 10 & 3
Description : During coal carbonisation process, the conversion of semi-coke to coke is accompanied by an increase in the __________ of the mass. (A) Density (B) Porosity (C) Electrical resistivity (D) None of these
Last Answer : (A) Density
Description : Degree of carbonisation of coal during coke making can be roughly judged by the __________ of the coke produced. (A) Colour (B) Moisture content (C) Ash content (D) Volatile matter
Last Answer : (D) Volatile matter
Description : Soft coke is not (A) Produced by low temperature carbonisation of coal (B) A domestic fuel (C) Used in blast furnaces (D) None of these
Last Answer : (C) Used in blast furnaces
Description : Low temperature carbonisation of coal produces (A) Metallurgical coke (B) Soft coke (C) Very low calorific value coke oven gas (D) No by-products
Last Answer : (B) Soft coke
Description : With increase in the temperature of carbonisation of coal (A) Hydrogen content of coke oven gas increases due to cracking ofhydrocarbons (B) Methane content in the coke oven gas decreases and carbon monoxide content increases ( ... compensated by increase in CO & H2 content (D) All (A), (B) and (C)
Description : A coal having higher volatile matter content, has lower (A) Smoking tendency on burning (B) Coke oven gas yield on carbonisation (C) Chance of catching fire during storage in open space (D) Ignition temperature
Last Answer : (D) Ignition temperature
Description : In low temperature carbonisation of coal, the (A) Yield of coke oven gas is 290 Nm3 /ton dry coal (B) Volatile matter in coke is zero (C) Temperature maintained is 700°C (D) Yield of tar is about 3% of dry coal
Last Answer : (C) Temperature maintained is 700°C
Description : Fussain (A) Is friable, charcoal like substance (B) Has highest fixed carbon and lowest volatile matter content of all the four banded components of coal (C) Is non-coking, but when blended with highly coking ... its swelling and produces high strength coke on carbonisation (D) All (A), (B) and (C)
Description : Prime coking coal is always blended with medium or non- coking coal before carbonisation (A) To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls (B) Because, it alone produces unreactive coke (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : The yield of tar from high temperature carbonisation of dry coal is about __________ percent. (A) 3 (B) 12 (C) 22 (D) 0.3
Last Answer : (A) 3
Description : During the carbonisation of coal (A) All tar is evolved at < 600°C (B) Evolution of H2 and formation of methane and aromatics occur at > 700°C (C) Hard semi-coke starts shrinking at 600°C (D) All (A), (B) and (C)
Description : Undercharging of coal in the by-product coke ovens results in (A) Decrease in the c.v. of coke oven gas (B) Increase in its throughput (C) Increase in the c.v. of coke oven gas
Last Answer : (A) Decrease in the c.v. of coke oven gas
Description : With increase in the time of carbonisation at a particular temperature(say 1000°C), the __________ percentage in coke oven gas increases. (A) Hydrogen (B) Methane (C) Unsaturated hydrocarbons (D) All (A), (B) and (C)
Last Answer : (A) Hydrogen
Description : High ash coals (A) Are soft & friable (poor strength and size stability) (B) Require longer time of carbonisation as ash offers resistance to heat transfer (C) Produce larger quantity of coke oven gas (D) None of these
Last Answer : (A) Are soft & friable (poor strength and size stability)
Description : Coking time in a commercial high temperature coal carbonisation plant is about __________ hours. (A) 6 (B) 18 (C) 28
Last Answer : (B) 18
Description : High temperature carbonisation of coal takes place at __________ °C. (A) 2000 (B) 600 (C) 1100 (D) 1600
Last Answer : (C) 1100
Description : High temperature carbonisation of coal takes place at __________ °C. (A) 2000 (B) 700 (C) 1100 (D) < 500
Description : Producer gas is obtained by A. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast B. carbonisation of bituminous coal C. passing steam over incandescent coke D. passing air and a large amount of steam over waste coal at about 650°C
Last Answer : Answer: A
Description : In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred (A) Through a metallic wall (B) By direct contact of hot flue gas with air (C) By ... material (like chequor bricks) and then heating the air from this hot material (D) None of these
Last Answer : (C) By heating an intermediate material (like chequor bricks) and then heating the air from this hot material
Description : Regenerators are used for waste heat recovery in (A) By-product coke ovens (B) Beehive coke oven (C) Blast furnace stoves (D) Soaking pits
Last Answer : (A) By-product coke ovens
Description : The temperature at which plastic layer formation takes place during carbonisation of coal varies from __________ °C. (A) 100 to 150 (B) 350 to 450 (C) 550 to 650 (D) 700 to 850
Last Answer : (B) 350 to 450
Description : Low temperature carbonisation of coal takes place at __________ °C. (A) 300 (B) 1100 (C) 700
Last Answer : (C) 700
Description : Low temperature carbonisation of coal takes place at __________ °C. (A) 300 (B) 1100 (C) 700 (D) 900
Description : Beehive coke ovens are made of __________ bricks. (A) Silica (B) Fireclay (C) Silicon carbide (D) Corundum
Last Answer : (A) Silica
Description : With increases in carbonisation temperature (A) Coke even gas yield increases (B) Tar yield increases (C) Hydrogen percentage in the coke oven gas decreases (D) Methane percentage in the coke oven gas increases
Last Answer : (A) Coke even gas yield increases
Description : Which of the following is not a by-product recovered in a high temperature coal carbonisation plant? (A) Benzol (B) Pitch-creosote mixture (PCM) (C) Naphthalene (D) Ethylene
Last Answer : (D) Ethylene
Description : In low temperature carbonisation (as compared to high temperature carbonisation) of coal (A) Ammonia yield is more (B) Aliphatic tar is produced (C) Free carbon in tar is more (D) All (A), (B) and (C
Last Answer : (B) Aliphatic tar is produced
Description : Coal tar (produced by high temperature carbonisation) is the main source of (A) Aromatic compounds (B) Aliphatic compounds (C) Paraffins (D) Olefins
Last Answer : (A) Aromatic compounds