The method of zone refining of metals is based on the principle of

• higher melting point of impurity than that of the pure metal

• greater noble character of the solid metal than that of the impurity

• greater solubility of the impurity in the molten state than in the solid.

• greater mobility of the pure metal than that of the impurity.

Name a method to get titanium metal in the pure state.

Zinc refining is a method to obtain

• Very high temperature

• Ultra pure Al

• Ultra pure Germanium
• Ultra pure oxides

Define the term mineral.

What type of ores are dressed up by magnetic separation method?

Name two metals which occurs native(free) in nature.

• infusible impurities to fusible material

• soluble impurities to insoluble impurities

   
• fusible impurities to infusible impurities
• mineral into silicate

In electro refining of metals, the pure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of

• Silver

• Copper

• Aluminium

• Zinc

Electrochemical process (electrolysis of fused salt) is employed to extract:

• iron

• lead

• sodium

• silver