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)
Last Answer : (D) All (A), (B) and (C)
Description : A coal containing high amount of volatile matter will have (A) Low ignition temperature (B) Very little ash content (C) High fusion point of its ash (D) Low adiabatic flame temperature
Last Answer : (A) Low ignition temperature
Description : Pulverised coal used in boiler firing need not have (A) Less moisture content (B) High fusion point of its ash (C) High bulk density (D) Lower ash conten
Last Answer : (B) High fusion point of its ash
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 : In producer gas making furnace, steam is added along with air to mainly control the (A) Fusion of coal ash & clinker formation (B) C. V. of producer gas (C) Temperature of producer gas (D) Tar content in producer gas
Last Answer : (A) Fusion of coal ash & clinker formation
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 advantages of firing pulverised coal in the furnace lies in the fact that, it (A) Permits the use of high ash content coal (B) Permits the use of low fusion point ash coal (C) Accelerates the burning rate and economises on fuel consumption (D) All (A), (B) and (C)
Last Answer : (C) Accelerates the burning rate and economises on fuel consumption
Description : A good quality coal should have (A) Low fusion point of ash (B) High ash content (C) High sulphur (D) None of these
Last Answer : (D) None of these
Description : The advantage of firing pulverised coal in the furnace lies in the fact, that it (A) Permits the use of high ash content coal (B) Permits the use of low fusion point ash coal (C) Accelerates the burning rate and economises on fuel combustion (D) All (A), (B) and (C)
Last Answer : (C) Accelerates the burning rate and economises on fuel combustion
Description : A good quality coal should have (A) Low fusion point of ash (B) High ash content (C) High sulphur content (D) None of these
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)
Description : A coal with high ash content (A) Has higher calorific value (B) Is harder and stronger (C) Is not subjected to washing (D) Has low quantity of mineral matter
Last Answer : (B) Is harder and stronger
Description : The weathering index of a coal (A) Gives an idea of the fusion temperature of ash (B) Is related to its calorific value (C) Is a measure of its size stability, when stored & exposed to weather (D) Is a measure of its caking tendency
Last Answer : (C) Is a measure of its size stability, when stored & exposed to weather
Description : During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Washing of coal decreases its (A) Caking index (B) Mineral matter content (C) Ash content (D) Both (B) and (C)
Last Answer : (B) Mineral matter content
Description : A good metallurgical coke should have very low (A) Sulphur & phosphorous content (B) Porosity (C) Fusion point of its ash (D) Hardness & strength
Last Answer : (A) Sulphur & phosphorous content
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 : Fusion point of coal ash generally varies from 1000 to 1700° C. Ash having fusion point less than __________ °C is liable to form clinker. (A) 1100 (B) 1250 (C) 1350 (D) 1400
Last Answer : (A) 1100
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 : 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 : 64-132) rank coal (ASTM) means a coal with 64% (A) Fixed carbon and having a heating value around 13, 200 BTU/1b (B) Ash and heating value around 13, 200 BTU/1b (C) Fixed carbon and heating value around 132 BTU/1b (D) None of these
Last Answer : (A) Fixed carbon and having a heating value around 13, 200 BTU/1b
Description : 64-132) rank coal (ASTM) means a coal with 64% (A) Fixed carbon and having a heat value of 13, 200 BTU/1b (B) Ash and a heating value of 13, 200 BTU/1b (C) Fixed carbon and a heating value of 132 BTU/1b (D) None of these
Last Answer : (A) Fixed carbon and having a heat value of 13, 200 BTU/1b
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 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 : Froth floatation is used for (A) Washing fine coal dust (< 0.5 mm size) (B) Washing lump coal (> 80 mm size) (C) Removing ash from the coal based on difference in specific gravity of coal and ash
Last Answer : (A) Washing fine coal dust (< 0.5 mm size)
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 : 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)
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 : 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
Description : A good coking coal should have high __________ content. (A) Ash (B) Sulphur & phosphorus (C) Moisture (D) None of these
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 : Which furnace burns low-ash fusion coal and retains most of the coal ash in the slag?
Last Answer : Cyclone furnace.
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 : A good metallurgical coke (A) Should have high porosity (B) Should be brittle (C) Must contain moderate quantities of ash, moisture, sulphur and volatile matters (D) Should have low fusion point of its ash
Last Answer : (A) Should have high porosity
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
Last Answer : Option D
Description : Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the (A) Physical nature, ash content and fineness of the coal (B) Amount of excess air supplied and load on the boiler (C) Type of burner and combustion chamber (D) All (A), (B) and (C)
Description : Mineral matter content (M) and ash content (A) in coal are approximately related as (A) M = 1.1A (B) M = A (C) M = 1.5A (D) M = 2A
Last Answer : (A) M = 1.1A
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 : 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 : During coking of coal, the ash content (percentage) (A) Increases (B) Decreases (C) Remain constant (D) None of these
Last Answer : (A) Increases
Description : Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent. (A) 6 (B) 12 (C) 18 (D) 24
Last Answer : (D) 24
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 : Washing of coal is done to reduce the (A) Inherent impurities (B) Adhering impurities (C) Mineral matter (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases. (A) Reduce SO2 content in (B) Catalytically convert SO2 to SO3 in (C) Increase the dew point of (D) None of these
Last Answer : (A) Reduce SO2 content in
Description : Coal is pulverised before burning in large capacity boiler furnaces mainly to (A) Ensure its complete combustion (B) Facilitate easy ash removal (C) Enhance its calorific value (D) Provide trouble free operation
Last Answer : (A) Ensure its complete combustion
Description : For long flame and easy ignition, the coal used should have (A) High volatile matter (B) Low ash (C) High calorific value (D) High ash
Last Answer : (A) High volatile matter
Description : In primitive days, __________ was being manufactured by Leblanc Process. (A) Alum (B) Washing soda (C) Soda ash (D) Calcium carbide
Last Answer : (C) Soda ash