Video Transcript
Which of the following gases are
hot waste gases mainly comprised of? (1) Carbon monoxide, (2) steam, (3)
oxygen, (4) hydrogen, (5) carbon dioxide, or (6) sulfur dioxide. (A) (1) and (5); (B) (3), (5), and
(6); (C) (1) and (2); (D) (3) and (4); or (E) (2), (3), and (4).
In this question, we want to know
what waste gases are produced in the extraction of iron in the industrial method of
iron extraction using a blast furnace.
A mixture of iron ore, coke, and
limestone is known as charge. This charge travels via conveyor
belts to the top of the blast furnace. The following illustration shows a
simplified version of the structure of a blast furnace. Conveyor belts run all day and
night and constantly transport charge to the blast furnace. Once inside, multiple chemical
reactions happen concurrently in the blast furnace. Coke is initially burned with hot
air, but more specifically oxygen, to produce carbon dioxide and heat energy. This combustion reaction is highly
exothermic and releases a lot of heat energy.
Carbon monoxide is produced in a
reaction between further supplies of coke and the carbon dioxide. Carbon monoxide gas acts as a
reducing agent as it travels through the blast furnace. The carbon monoxide molecules
reduce the iron oxide molecules that are primarily found in the middle and high
sections of the blast furnace. Molten iron, slag, and nitrogen gas
are also produced during this process. However, the main waste gases are
carbon dioxide and carbon monoxide. These are given the labels (1) and
(5).
So the answer to the question
“Which of the following gases are hot waste gases mainly comprised of?” is (A), (1)
and (5).
