The main function of limestone in the blast furnace is to
Answer Details
The main function of limestone in the blast furnace is to remove impurities. When heated, limestone decomposes to form calcium oxide (CaO), which reacts with the impurities (mainly silica and alumina) to form slag. The slag, being less dense than molten iron, floats on top of it and can be easily removed. This process is known as fluxing, and it helps to purify the molten iron. In addition, the limestone also helps to regulate the temperature in the furnace and provides the necessary basicity for the chemical reactions to occur. Therefore, the correct option is: "remove impurity".