Discuss the application of following in extraction of metals. Support your answer with suitable examples [3] [15] a. Blast furnace b. Pre-dominance area diagram c.Fluidized bed roasting

a. Blast Furnace: A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. The blast furnace is the principal means of extracting iron from its ores. The raw materials, iron ore, coke, and limestone, are added from the top, and a blast of hot air is introduced from the bottom. This causes the coke to burn, producing carbon monoxide which reacts with the iron ore, reducing it to molten iron. For example, in the extraction of iron, the furnace is charged with iron ore, limestone and coke. The coke burns in a controlled way to produce heat and raise the temperature of the iron ore.

b. Pre-dominance Area Diagram: Pre-dominance area diagrams are used in hydrometallurgy to determine the most stable species of a metal in an aqueous solution as a function of pH and potential. These diagrams are useful in the extraction of metals as they help in predicting the conditions under which a certain metal ion species is most stable. For example, in the extraction of copper, a pre-dominance area diagram can be used to determine the pH and potential at which copper ions are most stable, which can then be used to optimize the extraction process.

c. Fluidized Bed Roasting: Fluidized bed roasting is a process used in the extraction of metals where the ore is heated in a bed of particles, which are fluidized by passing gas through the bed. This process is used to convert sulfide ores into oxides, which are easier to extract. The fluidized bed allows for better mixing and contact between the ore and the roasting gases, leading to more efficient roasting. For example, in the extraction of zinc, fluidized bed roasting is used to convert zinc sulfide ore into zinc oxide, which is then reduced to metallic zinc.