Q1: Which of the following is a neutral flux used in the pyrometallurgy of metal extraction?

ANS:B - Flourspar

Fluorspar, also known as fluorite, is a mineral composed primarily of calcium fluoride (CaF2). It is commonly used as a flux in the pyrometallurgy of metal extraction. Here's an explanation of its role and properties:

1. Flux: In pyrometallurgy, fluxes are substances added to ores during smelting to facilitate the removal of impurities by forming a slag. Fluorspar acts as a flux by combining with impurities in the ore to form a low-melting-point slag. This slag floats on top of the molten metal and can be easily separated, thus aiding in the purification of the metal.
2. Low Melting Point: One of the key properties of fluorspar is its relatively low melting point. When added to the smelting process, it lowers the overall melting point of the mixture, which helps to reduce the energy required for smelting and improves the efficiency of the process.
3. Chemical Inertness: Fluorspar is chemically inert under typical smelting conditions, meaning it does not react with the metal being extracted or with other components of the smelting process. This property ensures that fluorspar does not introduce unwanted impurities into the final metal product.
4. Fluorine Content: Fluorspar contains fluorine, which can have various effects on the smelting process. In some cases, fluorine can enhance the removal of certain impurities or improve the fluidity of the slag. However, excessive fluorine content can also lead to issues such as increased volatility and environmental concerns.
5. Application: Fluorspar is commonly used as a flux in the smelting of metals such as iron, steel, aluminum, and copper. It is particularly effective in processes where high temperatures are involved, such as in blast furnaces and electric arc furnaces.