. Highly caking coals
(A) Produce weak coke
(B) Produce strong coke
(C) May damage the coke oven walls during carbonisation
(D) Both (B) and (C)

1 Answer

Answer :

(D) Both (B) and (C)

Related questions

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 : 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 : Pick out the wrong statement. (A) Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal (B) Ammonia is recovered in the form of ammonium sulphate in direct ... indicates poor caking properties of coal (D) Wash oil is used for scrubbing Benzol from coke oven gas

Last Answer : (C) A high swelling index number of coking coal indicates poor caking properties of coal

Description : Pick out the wrong statement: (A) Carburetted water gas is also called blue gas (B) Coals are divided in four species according to their carbon content in Seylor's classification (C) Carbonisation time ... and net calorific value of a fuel is the same, if it does not contain hydrogen or hydrocarbons

Last Answer : (A) Carburetted water gas is also called blue gas

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 : Anthracite can be used for (A) Recarbonising steel (B) Making carbon electrodes (C) Blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke (D) All (A), (B) and (C)

Last Answer : (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 : 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 : Width of the coke oven towards coke side is slightly more than that on pusher side to (A) Facilitate easy discharging of coke as it swells during carbonisation (B) Facilitate uniform heating of the oven (C) Increase the output of the coke (D) None of these

Last Answer : (A) Facilitate easy discharging of coke as it swells during carbonisation

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 : Coals used for the generation of producer gas should have (A) High caking index (B) Low fusion point of ash (C) High volatile matter content (D) Very low ash content (8-10%)

Last Answer : (C) High volatile matter content

Description : Fat coals' are those coals which have very high (A) Caking capacity (B) Volatile matter content (C) Fusion point of its ash (D) Inherent moisture conten

Last Answer : (A) Caking capacity

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)

Last Answer : (D) All (A), (B) and (C)

Description : With increase in moisture content of coal, its (A) Calorific value increases (B) Caking properties diminish (C) Swelling during carbonisation becomes excessive (D) None of these

Last Answer : (B) Caking properties diminish

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 : 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 : 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)

Last Answer : (D) All (A), (B) and (C)

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 : 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 : 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 : 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)

Last Answer : (D) All (A), (B) and (C)

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 : 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 : 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 : 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 : Coke oven walls are lined with __________ bricks. (A) Silica (B) Tar-dolomite (C) Low thermal conductivity (D) Fire clay

Last Answer : (A) Silica

Description : Pick out the wrong statement. (A) Cokes of high reactivity are obtained from weakly coking coals (B) Cokes of high reactivity are obtained from strongly coking coals (C) Reactivity of coke is inversely proportional to its absolute density (D) Abrasion index of the coke is a measure of its hardness

Last Answer : (B) Cokes of high reactivity are obtained from strongly coking coals

Description : Caking coal is desirable for (A) Burning on travelling grate (B) Coke making (C) Burning on firebars (D) All (A), (B) and (C)

Last Answer : (B) Coke making

Description : Caking index of the coal blend used for the manufacture of metallurgical coke should be around (A) 5 (B) 21 (C) 40 (D) 48

Last Answer : (B) 21

Description : Caking index of coal blend used for blast furnace coke making is about (A) 8 (B) 12 (C) 22 (D) 36

Last Answer : (C) 22

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 : 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)

Last Answer : (D) All (A), (B) and (C)

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 : 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 : Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr. (A) 2.5 (B) 0.5 (C) 10 (D) 20

Last Answer : (A) 2.5

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 : 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 : 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 : 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)

Last Answer : (D) All (A), (B) and (C)

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

Last Answer : (D) None of these

Description : The main product of high temperature carbonisation of coal is (A) Coke (B) Ammonia (C) Tar (D) Phenol

Last Answer : (A) Coke

Description : Conditioners like finely divided peat are added to the fertiliser to (A) Counteract burning (B) Avoid caking & hardening (C) Produce bulk (D) Increase its solubility

Last Answer : (B) Avoid caking & hardening

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 : 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 : Percentage of hydrogen in coke oven gas may be around (A) 10 (B) 25 (C) 45 (D) 60

Last Answer : (D) 60

Description : Percentage of methane in coke oven gas may be around (A) 5 (B) 15 (C) 25 (D) 50

Last Answer : (C) 25

Description : Sometimes water is sprayed during coal charging in the coke oven, which helps in (A) Prevention of clinker formation in the oven (B) Controlling the dust nuisance while charging the coal (C) Reducing the cracking of hydrocarbons in ... represented by C + H2O = CO + H2 ) (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)