Description : Pick out the wrong statement. (A) Percentage of ash in coke produced from medium coking coal is more than that in coal (B) The calorific value (kcal/Nm3 ) of coke oven gas reduces on ... plants in India at Talcher (Orissa) and Ramagundam (A.P) employ Kopper-Totzek process of coal gasification
Last Answer : (C) Ash is normally removed as 'fly-ash' in Kopper-Totzek process of coal gasification
Description : Which of the following statement (s) regarding India's coal reserves is/are true ? 1. Over 90 percent of total reserves are located in the valleys of Son, Damodar, Mahanadi and Godavari 2. Indian coal reserves are characterised ... reserves (a) I only (b) I and III (c) II and III (d) I, II and III
Last Answer : Ans: (c)
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 : A good coking coal should have high __________ content. (A) Ash (B) Sulphur & phosphorus (C) Moisture (D) None of these
Last Answer : (D) None of these
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 : Volatile matter content in coking coal may be about __________ percent. (A) 1 (B) 7 (C) 22 (D) 46
Last Answer : (C) 22
Description : Quantity of coke produced from metallurgical coal may be around __________ percent. (A) 30 (B) 50 (C) 75 (D) 95
Last Answer : (C) 75
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 : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : During coking of coal, the ash content (percentage) (A) Increases (B) Decreases (C) Remain constant (D) None of these
Last Answer : (A) Increases
Description : Washing of coal (A) Reduces its ash & sulphur content (B) Improves its coking properties (C) Increase the fusion point of its ash by removing chlorine compounds (D) All (A), (B) and (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 : Which of the following would require least amount of secondary air for combustion? (A) Coke breeze containing 25% ash and 2% volatile matter (B) Anthracite containing 10% volatile matter and 8% ash ... ash and 25% volatile matter (D) Semi-bituminous coal containing 25% ash and 20% volatile matter
Last Answer : (A) Coke breeze containing 25% ash and 2% volatile matter
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 : Softening temperature of coal ash is a measure of the __________ of coal. (A) Caking tendency (B) Coking tendency (C) Clinkering tendency (D) Size stability
Last Answer : (C) Clinkering tendency
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 : Volatile matter content of metallurgical coke may be around __________ percent. (A) 1-2 (B) 10-15 (C) 22-26 (D) 30-33
Last Answer : (A) 1-2
Description : Ash content in the middling coal (a byproduct of coal washeries) in India ranges between __________ percent. (A) 15 to 25 (B) 35 to 45 (C) 55 to 75 (D) 75
Last Answer : (B) 35 to 45
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 : 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 : Petroleum coke is commercially produced by the __________ process. (A) Hydrocracking (B) Visbreaking (C) Fluid catalytic cracking (D) Delayed coking
Last Answer : (D) Delayed coking
Description : Which of the following fuels is generally not used in thermal power plant boiler firing? (A) Furnace oil, light diesel oil and tar/PCM (B) Pulverised coking coal (C) Coal middling from washeries (D) B.F. gas, coke oven gas and L.D. converter gas
Last Answer : (B) Pulverised coking coal
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)
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 : 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 : 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 : The reason for excessive clinker formation in gas producers is the (A) Use of coal/coke containing a high % of fines and ash (B) Use of fuel having too low an ash fusion temperature (C) Development of hot spots in the fuel bed and an abnormally high rate of gasification (D) All (A), (B) and (C)
Description : Which of the following is unsuitable fuel for producer gas manufacture? (A) Coke (B) Anthracite (C) Coal having low fusion point of its ash (D) Coal having high fusion point of its ash
Last Answer : (C) Coal having low fusion point of its ash
Description : Commercial production of soda ash by Solvay process requires limestone, __________ as raw materials. (A) Coke and sand (B) Brine and coal (C) Coke and caustic soda (D) None of these
Last Answer : (B) Brine and coal
Description : Coking time in beehive coke oven is about (A) 12 hours (B) 2-3 days (C) One week (D) Two weeks
Last Answer : (B) 2-3 days
Description : The Al2O3 content of cryolite in Hall-Heroult cell is maintained between __________ percent. (A) 2-5 (B) 18-20 (C) 12-15 (D) 6-12
Last Answer : (A) 2-5
Description : Carbon content of pitch (residue of coal tar distillation) is around __________ percent. (A) 70 (B) 55 (C) 80 (D) 94
Last Answer : (D) 94
Description : Cannel coal (A) Is non-coking (B) Has a high volatile matter content and burns with a luminous smoky flame (C) Is a non-banded coal which can be ignited easily with a match stick or candle flame, hence is so named (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 : 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 : Higher percentage of ash in coal meant for the production of metallurgical grade coke (A) Decreases the hardness of coke (B) Decreases the abrasion resistance of coke (C) Causes brittleness in steel (D) None of these
Description : Which of the following constituents of coal is the most important in the production of coke? (A) Moisture (B) Ash (C) Volatiles (D) Carbon
Last Answer : (D) Carbon
Description : Coke compared to the coal from which it has been made, contains (A) Less volatile matter (B) More carbon (C) Greater percentage of ash (D) All (A), (B) and (C)
Description : Fat' coal means a coal having (A) Low calorific value (B) High volatile matter (C) Low ash content
Last Answer : (B) High volatile matter
Description : A coal having higher volatile matter content will necessarily have lower (A) Ash fusion temperature (B) Calorific value (C) Ignition temperature (D) Caking index
Last Answer : (C) Ignition temperature
Description : The specific gravity of coal depends mainly on its __________ content. (A) Carbon (B) Volatile matter (C) Ash (D) Moisture
Last Answer : (C) Ash
Description : Coal is heated in presence of air to a temperature of about __________ °C, while determining its ash content for proximate analysis. (A) 500 (B) 750 (C) 950 (D) 1100
Last Answer : (B) 750
Description : Ultimate analysis of coal determines its __________ content. (A) Carbon, hydrogen, nitrogen & sulphur (B) Carbon, ash, sulphur & nitrogen (C) Carbon, sulphur, volatile matter & ash (D) Carbon, volatile matter, ash & moisture
Last Answer : (A) Carbon, hydrogen, nitrogen & sulphur
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture, volatile matter, ash & fixed carbon (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture, volatile matter, ash & fixed carbon
Description : A coal with high __________ content, would ignite most easily. (A) Fixed carbon (B) Volatile matter (C) Ash (D) Oxygen
Last Answer : (B) Volatile matter
Description : Fusion point of coal ash increases with increase in its __________ content. (A) Iron sulphate (B) Iron silicate (C) Lime and magnesia (D) All (A), (B) and (C)
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture & volatile matter (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture & volatile matter
Last Answer : (C) Carbon, sulphur, volatile matter & ash
Last Answer : Option D
Description : A coal with high ash content is undesirable, as (A) It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber (B) The ash in molten condition gets absorbed in the pores of the ... and stick to the boiler tubes thereby reducing the heat transfer (D) All (A), (B) and (C)