Which one of the following is used to remove silicon dioxide in Serpeck's process of purification of bauxite?

Options

A. `CaO`
B. `Na_(2)CO_(3)`
C. Coke
D. Nickel

Answer

C

Explanation

Serpeck's process is used when silica is present in considerable amounts in bauxite ore. The ore is mixed with coke and heated at `1800^(@)C` in the presence of nitrogen. Silica is reduced to silicon which volatilizes off at this temperature:
`SiO_(2) + 2C rarr Si + 2CO`