Out of C and CO, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore?
Describe the principle involved in each of the following processes.
(i) Mond process for refining of Nickel.
(ii) Column chromatography for purification of rare elements.
Explain how the phenomenon of adsorption finds application in each of the following processes:
(i) Production of vacuum
(ii) Heterogeneous catalysis
(iii)Froth Floatation process
Describe the principle behind each of the following processes:
(i)Vapour phase refining of a metal.
(ii)Electrolytic refining of a metal.
(iii)Recovery of silver after silver ore was leached with NaCN.
(i) What is the principle behind the zone refining of metals?
(ii) What is the role of silica in the extraction of copper?
(iii) How is 'cast iron' different from 'pig iron'?
Outline the principles of refining of metals by the following methods:
(i) Zone refining
(ii) Vapour phase refining
Principles of refining of metals by:
(i) Zone refining: The impurities are more soluble in the melt than in the solid state of the metal. Hence, the pure metal crystallises out of the melt and impurities pass on into the adjacent molten zone and like this at one end impurities get concentrated. Silicon, indium, boron, gallium etc. can be purified by this process.
(ii) Vapour phase refining: Vapour phase refining is the process of refining metal by converting it into its volatile compound and then, then decomposing it to obtain a pure to carry out this process
(a) The metal should form a volatile compound with an available reagent.
(b) The volatile compound should be easily decomposable so that the metal can be easily recovered.
Nickel, Zirconium, and titanium are using this method.