Coal containing large quantity of _______________ are difficult to wash?

Related Mcqs:

1. A coal containing very high percentage of durain is called ______________ coal?

   A. Bright
   B. Splint
   C. Non-banded
   D. Boghead

2. Calorific value of coal middling generated in coal washeries during washing of coal may be around _____________ Kcal/kg?

   A. 1000
   B. 4000
   C. 6000
   D. 8000

3. When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the _______________ of coal?

   A. Carbonisation
   B. Oxidation
   C. Coalification
   D. Gasification

4. A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be_________________?

   A. More
   B. Less
   C. Same
   D. Data insufficient; can’t be predicted

5. 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

6. A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the_________________?

   A. Presence of large quantity of hydrogen in the fuel
   B. Low calorific value of the fuel
   C. High sulphur content in the fuel
   D. Lack of thorough mixing of fuel with air

7. (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

8. 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

9. 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.

10. Commercial production of petrol from coal (as practised in a factory at Sasol in South Africa) is done by the ________________ of coal?

    A. Hydrogenation
    B. Gasification
    C. Carbonisation
    D. None of these