MetallurgyHard
Question
The major role of fluorspar (CaF2) which is added in small quantities in the electrolytic reduction of alumina dissolved in fused cryolite (Na3AlF6) is :
Options
A.as a catalyst.
B.to make the fused mixture very conducting.
C.to lower the temperature of the melt.
D.to decrease the rate of oxidation of carbon at anode.
Solution
Na3[AlF6] being ionic provides ions, thus increases the conductivity of the mixture and lowers its melting point (impurity lowers the melting point of the melt).
Create a free account to view solution
View Solution FreeMore Metallurgy Questions
Of the following the metals that cannot be obtained by electrolysis of the aqueous solution of their salts are :...Which is not correct statement ?...A sulphide ore like ZnS is first roasted into its oxide prior to reduction by carbon because :...Haematite ore is concentrated by :...Which of the following statement(s) is (are) incorrect ?...