MetallurgyHard
Question
In which of the following extration no reducing agent is required ?
Options
A.Iron from haematite.
B.Aluminium from bauxite.
C.Magnesium from carnallite.
D.Zinc from zinc blende
Solution
(A) 3Fe2O3 + CO → 2Fe3O4 + CO2 ; Fe3O4 + CO → 3FeO + CO2 ; FeO + CO → Fe + CO2
(B) The purified Al2O3 is mixed with Na3AlF6 (cryolite) or CaF2 (fluorspar) ) which lowers the melting point of the mixture and increases conductivity. The fused matrix is electrolysed.
Cathode : Al3+ (melt) + 3e- Al(l)
Anode : C(s) + O2- (melt) CO(g) + 2e-
C(s) + 2O2- (melt) CO2 (g) + 4e-
Electrons act as reducing agent in electrolytic reduction.
(C) The molten mixture containing MgCl2, NaCl and CaCl2 is electrolysed.
MgCl2 ⇋ Mg2+ + 2Cl-
At cathode : Mg2+ + 2e- Mg(99% pure) ;
At anode : 2Cl- Cl2 + 2e-
Electrons act as reducing agent in electrolytic reduction.
(D) 2ZnS + 3O2
2ZnO + 2SO2
ZnO + C
Zn + CO
(B) The purified Al2O3 is mixed with Na3AlF6 (cryolite) or CaF2 (fluorspar) ) which lowers the melting point of the mixture and increases conductivity. The fused matrix is electrolysed.
Cathode : Al3+ (melt) + 3e- Al(l)
Anode : C(s) + O2- (melt) CO(g) + 2e-
C(s) + 2O2- (melt) CO2 (g) + 4e-
Electrons act as reducing agent in electrolytic reduction.
(C) The molten mixture containing MgCl2, NaCl and CaCl2 is electrolysed.
MgCl2 ⇋ Mg2+ + 2Cl-
At cathode : Mg2+ + 2e- Mg(99% pure) ;
At anode : 2Cl- Cl2 + 2e-
Electrons act as reducing agent in electrolytic reduction.
(D) 2ZnS + 3O2
2ZnO + 2SO2 ZnO + C
Zn + CO Create a free account to view solution
View Solution FreeMore Metallurgy Questions
Aluminium is extracted by the electrolysis of...Haematite ore is concentrated by :...Which of the following represents the thermite reaction?...Carbon and CO gas are used to reduce which of the following pairs of metal oxides forexpiration of metals ?...Silica is added to roasted copper ores during extraction in order to remove...