Explain the following processes of metallurgy Zone refining
Answers
Explanation:
(i) Zone refining: This method is based on the principle that impurities are more soluble in the molten state of metal (the melt) than in the solid state. In the process of zone refining, a circular mobile heater is fixed at one end of a rod of impure metal. As the heater moves, the molten zone of the rod also moves along with it. As a result, pure metal crystallizes out of the melt and the impurities pass to the adjacent molten zone. This process is repeated several times, which leads to the segregation of impurities at one end of the rod. Then, the end with the impurities is cut off. Silicon, boron, gallium, indium etc. can be purified by this process.
Explanation:
Definition of zone refining. : a technique for the purification of a crystalline material and especially a metal in which a molten region travels through the material to be refined, picks up impurities at its advancing edge, and then allows the purified part to recrystallize at its opposite edge.
Metallurgical engineering is based on the principles of science and engineering, and may be divided into process metallurgy, which is concerned with extracting metals from their ores to make refined alloys, and physical metallurgy, which involves the shaping, alloying, heat treatment, joining, corrosion protection and ...