A layer of coke is spread over bauxite during the extrection of aluminium. This acts as a/an

Options

A. flux
B. slag to remove impurities
C. reducing agent
D. insulation and does not allow heat to excape

Answer

D

Explanation

The fused electrolyte [a mixture containing alumina, cryolite `(Na_(3)AlF_(6))`, and fluorspar `(CaF_(2))` in the ratio of `20 : 40 : 20`] is covered with a layer of coke to prevent the escape of heat.