This set of Iron Making Multiple Choice Questions & Answers (MCQs) focuses on “Six Internal Zones”.
1. The blast furnace can be internally divided into 6 zones. Which of these zones comes first while moving from top to bottom?
a) Hearth
b) Cohesive zone
c) Granular zone
d) Dead man’s zone
View Answer
Explanation: The top most zone is the ‘Granular Zone’, it is mainly composed of coke and iron ore. The hearth is the last process-zone of a blast furnace. The ‘Dead man’s zone’ is the zone of inactive coke found just above the tuyere zone.
2. In which zone does the melting of iron and formation of slag begin?
a) Cohesive zone
b) Granular zone
c) Hearth
d) Dead man’s zone
View Answer
Explanation: The melting of iron and formation of slag starts in the cohesive zone. Here the melting point of iron decreases to almost 1200°C due absorption of carbon. The slag formed is of high FeO content. The Granular zone is a zone of solid charge. The hearth is the zone where the molten metal collects. The ‘Dead man’s zone’ is the zone of inactive coke found just above the tuyere zone.
3. What role does the hearth play in the process of iron making?
a) Serves as the inlet for charge
b) Supports the overlying burden
c) Collects the hot metal and slag
d) The chemical reactions occur in the hearth
View Answer
Explanation: The hearth acts as crucible for collecting hot metal and slag. The burden in the stack of the blast furnace is supported by the ‘Dead man’s Zone’. The chemical reactions occur mostly in the cohesive zone and the active coke zone.
4. What is the physical state of the cohesive zone?
a) Solid and granular
b) Liquid and viscous
c) Mushy and soft
d) Gaseous
View Answer
Explanation: The cohesive zone is the region where melting of the charge and formation of slag occurs, hence it is soft and mushy. The hearth is where the metal is completely melted and in liquid state. The granular zone consists of solid charge.
5. Which of the six zone has maximum operating temperature?
a) Granular zone
b) Tuyere zone
c) Hearth
d) Cohesive zone
View Answer
Explanation: The tuyere zone has the maximum temperature of approximately 2000°C.This is the region where the coke gets burnt and converted into useful heat and gaseous products.
6. What is the approximate shape of the stagnant coke zone (Dead man’s zone)?
a) Inverted V shape
b) Inverted U shaped
c) W shaped
d) No particular shape
View Answer
Explanation: The stagnant coke zone is of inverted V shaped. The hot blast cannot penetrate till the center of the blast furnace; hence the central portion is left behind.
7. How is the charge distributed in the ‘Granular zone’ of the blast furnace?
a) The layer of coke and iron ore is arranged in alternate layers
b) There is no particular arrangement of the coke and iron ore
c) Iron ore is heaped in top of coke
d) Coke is heaped on top of iron ore
View Answer
Explanation: In the ‘Granular zone’ the coke and iron ore are arranged in alternate layers. This kind of charge distribution helps in the formation of proper active coke zone and gas flow; hence affects productivity.
Sanfoundry Global Education & Learning Series – Iron Making.
To practice all areas of Iron Making, here is complete set of 1000+ Multiple Choice Questions and Answers.
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