Question

In the metallurgy of iron, when $CaC{{O}_{3}}$ is added to blast furnace, calcium ion appears as:
A. $CaO$
B. Metallic $Ca$
C. Gangue
D. Slag

Answer 1

Hint: Metallurgy of iron and alloys is known as ferrous metallurgy. From iron nickel alloys, irons are extracted in which it consists of $6%$ of meteoroids that fall on the earth. Earlier it was used as a decorative material and it is very rare on the earth. This process turns a molten iron into the steel.

Complete step by step answer:
In the first step of metallurgy of iron, we see that water is removed by roasting the ore, decomposing carbonates into oxides and converting sulphides into oxides.
Limestone is also known as impure $CaC{{O}_{3}}$ which is introduced into the top molten iron and slag is withdrawn at the bottom. The slag obtained is mostly calcium silicate. In blast furnaces, decomposition of limestone takes place that results in the formation of lime and carbon dioxide. The lime that is obtained acts as flux and later on it combines with silica, which results to give calcium silicate as a slag.
The reaction can be written as follows:
$CaC{{O}_{3}}\to CaO+C{{O}_{2}}$
$CaO+Si{{O}_{2}}\to CaSi{{O}_{3}}$
In this, $Si{{O}_{2}}$ is a flux and $CaSi{{O}_{3}}$ is slag. So, the calcium ion appears as slag in the metallurgy of iron.

So, the correct answer is Option D.

Additional information:
When all the carbon is removed from the iron, it gives high purity iron, which is known as wrought iron. It is soft and has little structure strength. It is used to make decorative gates and railings.
But in today’s time, mild steel is normally preferred instead of wrought iron.
Mild steel contains iron and carbon up to $0.25%$ . The presence of carbon makes the steel stronger than the pure iron. If we increase the percentage of carbon, the steel will become harder. Mild steel is used for wire, ship building.

Note: In conclusion, the concentrated ore is mixed with limestone and coke and results in the formation of lime. After that, lime acts as a flux and combines with silica to give calcium silicate.
Iron handles high temperature, therefore, it is used to make coal tongs and furnaces.
Iron has a tendency to rust easily and to prevent rusting, a process, known as galvanization, is used in which zinc is coated over iron.