Question

What is the principle behind the zone refining of metals?

Write the principles of Zone refining Methods

Describe the principle of the following process in detail.

Zone refining

Answer 1

This method is used for producing metal of high purity. Metal like germanium, gallium and indium are prepared by this method. This method is based on the principle that impurities are more soluble in molten state than in the solid state of the metal.

Answer 2

When a metal with a high degree of purity is required, this method is used. For example, this process refines silicon, gallium, and germanium, which are utilized as semiconductors. The method depends on the observation that an impurity’s solubility varies depending on whether the metal to be purified is liquid or solid.

The impure metal is cast into a thin rod using this method. This pole has a round heater attached to it. Slowly, the heater is moved along the rod. The rod melts at the heated zone, and while the heater continues, the impurities move to the nearby molten zone, causing the remaining pure metal to recrystallize. As the heater travels along the rod, the pollutants continue to flow from one zone to the next before eventually gathering at the other end of the rod. After a number of repetitions, the end that contains the impurities is finally cut off. The metal that makes up the remaining rod is highly pure.