Which method of refining is suitable for germanium?
Zone refining method
Solution : (i) Zone refining method is used for the refining of Germanium. It is based upon the principle. That the impurities are more soluble in molten state than in the solid state of metal.
What is zone refining give one example?
Zone refining is based on the principle that when an impure metal in a molten state is allowed to cool, only the metal crystallizes while the impurities remain in the molten state (mass) or melt. This method is widely used for refining metals that have a low melting point. e.g., tin, lead, bismuth.
Which metals are refined by zone refining?
Zone refining is a very useful method to get metals with very high purity such as silicon and germanium.
Is zone refining used for gallium?
GALLIUM metal as such cannot be purified by conventional zone refining generally used when metals and elements of high purity are required.
Which is not refined by zone refining?
Al is not purified by zone refining process.
Which metals zone refining is not used as method of refining?
Zone refining was first commercially used for germanium. As zone refining by using electrical heating coils did not work well with silicon because of its high melting point.
What is zone refining process?
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.
What is zone refining Class 10?
Zone refining is a technique to get highly pure crystals of impure elements (especially metals) by using melting and crystallization processes. In this, a narrow region of the crystal is heated so that impurities get melted and forms a molten zone that moves along the crystal.
Which metal is not used for zone refining?
Zone refining process was first invented by John Desmond Bernal. Zone refining was first commercially used for germanium. As zone refining by using electrical heating coils did not work well with silicon because of its high melting point.
Which principle is used for zone refining process?
relative solubilities of impurities in
– Zone refining process works on the principle that impurities are more soluble in molten metal than solid metal. So, the correct answer is “Option B”. Note: Remember zone refining process is based on the principle of relative solubilities of impurities in molten metal.
Who discovered zone refining?
scientist W.G. Pfann
Zone refining was first described by the U.S. scientist W.G. Pfann and was first used in the early 1950s to purify germanium for transistors. The purity achieved was hitherto unheard of—less than one part of detectable impurity in 10,000,000,000 parts of germanium.
How is germanium purified?
In refining germanium, the low-grade residues obtained from its ores are treated with strong hydrochloric acid, and the resulting germanium tetrachloride is distilled, purified by repeated redistillation, and hydrolyzed to form germanium dioxide, which is then reduced by hydrogen to a powdery form of the metal that is …
Is zone refining used for boron?
Solution : Zone refining. This method is used for metal which are required in very high purity. For example, extremely pure silicon, germanium, boron, gallium and indium are refined by this method.
Is gallium refined by zone refining method?
hence gallium is a metalloid so gallium arsenide is purified by zone-refining.
Is Tin refined by zone refining?
The purification of tin by a new method of zone refining is described. The method is characterized by alternating high-speed clockwise and anticlockwise rotations (0 to 3000 rpm) of the containing tube at short intervals (0.5 to 10 sec).
Is nickel used for zone refining?
Nickel is refined by mond’s process. Complete answer: Some of the methods that can be used for the refining of metals are distillation, liquation, poling, electrolysis, zone refining and vapour phase refining. Impure nickel metal is obtained from the reaction of nickel oxide with syngas at 473 K.
Who invented zone refining?
Chemical engineer William Pfann pioneered zone refining in 1950-51. By repeatedly passing a long tube filled with germanium horizontally through a series of electrical heating coils, he melted portions of the germanium and allowed them to recrystallize.
What is zone refining?