Video Transcript
Which of the following chemical
compounds, essential for the process that occurs inside a blast furnace, is produced
by limestone used in the blast furnace? (A) CaO, (B) CaCO3, (C) CaSiO3, (D)
SiO2, or (E) Fe3O4.
Blast furnaces can be used to
extract iron from its ore. Before the iron ore can be added to
the blast furnace, it must first be crushed, roasted, and mixed with other
chemicals. The iron ore is mixed with coke, a
product produced from the synthetic calcination of coal. Limestone, a calcium-based
sedimentary rock, is also added. Altogether, this mixture is known
as charge.
Inside of the blast furnace, the
limestone, which is primarily composed of calcium carbonate, decomposes to produce
calcium oxide and carbon dioxide. The calcium oxide then reacts with
sand impurities, which can be thought of as silicon dioxide, to produce calcium
silicate. Calcium silicate is the main
component of a waste product called slag.
From this information, we can see
that calcium oxide is the component produced by limestone, which is essential for
the removal of impurities in a blast furnace. Therefore, the correct answer is
answer choice (A), CaO.
