Chemical Industry Multiple Choice Questions on “Iron”.
1. Which among the following is not an iron ore?
a) Hematite
b) Magnetite
c) Siderite
d) Pyrrhotite
Answer: d
Clarification: Pyrrhotite is an ore of Ni whereas hematite (Fe2O3), magnetite (Fe3O4) and siderite (FeCO3) are the ores of Iron.
2. Which among the following is an essential chemical reaction for the manufacture of pig iron?
a) Fe2O3 + 3C → 2Fe + 3CO
b) FeS + C → Fe + CS
c) Fe3O4 + S → 3Fe + SO4
d) Fe2O3 + S → 2Fe + SO3
Answer: a
Clarification: Coke is reacted with hematite at a high temperature through a furnace. As air reacts with coke CO and heat is generated as iron oxide is reduced, molten iron gathers at the base of the furnace.
3. How can the production of pig iron be increased?
a) Increasing temperature decreasing pressure
b) Decreasing temperature
c) Increasing pressure
d) Decreasing pressure
Answer: c
Clarification: Increased production of pig iron can be achieved by increasing the pressure conditions. This reduces dust carry over and allows higher production rates.
4. What are the raw materials needed for the manufacture of pig iron?
a) Iron ore-Calcium-Coke
b) Iron ore-Coke
c) Iron ore-Calcium
d) Iron ore-Coke-Limestone
Answer: d
Clarification: Coke and limestone are introduced by conveyors onto a furnace which is reacted with the iron ore along with a hot air blast at a temperature of 600-800°C.
5. Coke consumption can be reduced in the manufacture of pig iron.
a) False
b) True
Answer: b
Clarification: Coke consumption can be reduced in the manufacture of pig iron by using supplementary oil injection. Up to 20% savings can be made.