In the basic oxygen process, which additive is used to bind impurities?

In the basic oxygen process, which additive is used to bind impurities?

• A. Steel is heated to red-hot
• B. Lime is added and combines with impurities
• C. Water is added to quench
• D. Oxygen is introduced in small amounts

Answer: (B)

In this process the key idea is using a flux to form a slag that binds impurities. Lime is added as a flux to molten iron in the basic oxygen furnace. It reacts with oxides like silica and alumina present in the melt to form calcium silicate and related compounds. This slag, which is less dense than the metal, floats to the top and traps impurities, allowing them to be skimmed off. Oxygen blowing oxidizes carbon and other elements, but the impurity binding specifically comes from the lime forming the slag. Water quenching isn’t used, and simply heating or introducing oxygen without the lime wouldn’t create the slag needed to remove impurities.

In this process the key idea is using a flux to form a slag that binds impurities. Lime is added as a flux to molten iron in the basic oxygen furnace. It reacts with oxides like silica and alumina present in the melt to form calcium silicate and related compounds. This slag, which is less dense than the metal, floats to the top and traps impurities, allowing them to be skimmed off. Oxygen blowing oxidizes carbon and other elements, but the impurity binding specifically comes from the lime forming the slag. Water quenching isn’t used, and simply heating or introducing oxygen without the lime wouldn’t create the slag needed to remove impurities.