Question

How are each of the following involved in iron metallurgy?

(a) slag; (b) pig iron; (c) steel; (d) basic-oxygen process?

Short answer

1. Slag is an unwanted by-product that contains the impurity ${\text{SiO}}_2$.
2. Pig iron is impure steel that contains 3-4 percent carbon.
3. Steel is a substantial iron alloy composed primarily of pure iron and low impurities such as$1-1.5\%C$.
4. The basic-oxygen process is a method for purifying pig iron into steel.

Step-by-step solution

Iron extraction

The conversion of naturally occurring iron-bearing materials into metallic iron is known as extraction. All industrial operations that turn raw resources into metallic iron are typically referred to as iron making.

(a) Slag reaction

Slag is a waste product formed when iron is purified using the reaction:

$\text{CaO}\left(s\right)+{\text{SiO}}_2$$\left(\mathrm{s}\right)\to {\text{CaSiO}}_3$ (l)

As a result, slag is an unwanted by-product that contains the impurity ${\text{SiO}}_2$.

(b) Items contained in pig steel

Pig iron is an impure steel that contains$3-4\%$ carbon. It may be refined to obtain pure steel and is used to cast iron items.

Therefore, Pig iron is an impure steel that contains 3-4 percent carbon.

(c) Composition of steel

Steel is a substantial iron alloy composed primarily of pure iron and low impurities such as $1-1.5\%C$.

Hence, Steel is a substantial iron alloy composed primarily of pure iron and low impurities such as $1-1.5\%C$.

(d) Method for purifying pig iron  

The basic-oxygen process is a method for purifying pig iron into steel. The pig iron is melted during this time, and oxygen gas is forced through the molten metal at high pressure. Impurities are converted to oxides, which react with$\text{CaO}$ to generate a slag that is decanted. As a result, pure molten steel is obtained.

As a result the basic-oxygen process is a method for purifying pig iron into steel.