purpose of flux in blast furnace
A. bring down the softening point of the gangue materials
B. reduce the viscosity of the slag
C. to maintain proper basicity
D. all of these
Select an option to see the answer and solution.
High top pressure in the blast furnace
A. decreases the time of contact between gas and solid
B. increases the time of contact between gas and solid
C. increases fuel consumption
D. increases the rate of solution loss reaction
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Dephosphorisation of molten pig iron is favoured by
A. oxidising and basic slag
B. reducing and basic slag
C. high activity co-efficient of phosphorous in metal
D. oxidising and neutral slag
Select an option to see the answer and solution.
High top pressure in a blast furnace operation
A. favours the solution loss reaction
B. suppresses the solution loss reaction
C. decreases gas-solid contact time
D. increases coke rate
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The zone where the entire charge is in semi-solid or in softened condition except coke inside the BF is called . . . . . . . . zone
A. stagnant coke zone
B. active coke zone
C. cohesive zone
D. Tuyere zone
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The primary source of heat in cupola melting is provided by the reaction:
A. C + O2 ⟶ CO2
B. C + H2 O ⟶ CO2 + H2
C. C + C2 O ⟶ 2CO
D. CaCO3 ⟶ CaO + CO2
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External desiliconisation of hot metal is carried out in the steel plant located at
A. Rourkela
B. Durgapur
C. Bokaro
D. Bhilai
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Humidification of the blast in the iron blast furnace leads to
A. lowering of the raceway temperature
B. increase in the raceway temperature
C. difficulty in pulverised coal injection
D. decrease of oxygen content in the hot metal
Select an option to see the answer and solution.
High top pressure in blast furnace
A. increases the silicon content in the hot metal
B. increases the sulfur content in the hot metal
C. increases the phosphorous content in the hot metal
D. increases the manganese content in the hot metal
Select an option to see the answer and solution.
The deadman's zone in the blast furnace consists of
A. closely packed central columm of coke, limestone and iron ore
B. gases only
C. closely packed central column of coke only
D. column of hot metal and slag
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The exit gases of blast furnace contains . . . . . . . . % carbon-monoxide, when equilibrium is achieved.
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Group I is a list of technologies for alternate methods of producing iron.
Group II is a list of terms you come across in the context of these technologies. Match the items.
Group I
Group II
P. MIDREX
1. Retort
Q. COREX
2. Rotary kiln
R. SL/RN
3. Smelting reduction
S. HyI- I
4. Shaft furnace
A. P-3, Q-1, R-2, S-4
B. P-4, Q-2, R-1, S-3
C. P-1, Q-3, R-2, S-4
D. P-4, Q-3, R-2, S-1
Select an option to see the answer and solution.
In the blast furnace, as the oxygen percentage in air blast increases, the
P. flame temperature increases
Q. blast volume increases
R. blast volume decreases
S. flame temperature decreases
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Blast furnace is a
A. counter-current reactor
B. co-current reactor
C. cross-current reactor
D. combination of all the three
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Pellets are not popular as a burden material as sinter in the iron blast furnace, because of their
A. shape
B. swelling tendency
C. poor reducibility
D. low mechanical strength
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Scaffolding is a
A. large mass of that material gets stuck to the furnace wall
B. excessive blast pressure resulting in counteracting the downward movement of stock
C. both A and B above
D. none of these
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The chemical formula of Wustite is
A. FeS2
B. Fe2 O3
C. Fe2 O4
D. FeO
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Maximum tonnage of . . . . . . . . is produced in blast furnace during iron making.
A. pig-iron
B. slag
C. gas
D. dust particles
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Solution loss reaction occurs
A. in the blast furnace shaft
B. during pretreatment of hot metal
C. in the LD process
D. during deoxidation in the ladle
Select an option to see the answer and solution.
An increase in ash content of coke by 1%, decreases the production rate by
A. 2 - 3%
B. 5 - 6%
C. 3 - 6%
D. 6 - 10%
Select an option to see the answer and solution.