Explain Aluminothermic process.

Explanation

Metallic oxides such as `Cr_(2)O_(3)` can be reduced by an aluminothermic process. In this process, the metal oxide is mixed with aluminium powder and placed in a fire clay crucible. To initiate the reduction process, an ignition mixture (usually magnesium and barium peroxide) is used.
`"BaO"_(2)+Mg to"BaO"+"MgO"`
During the above reaction a large amount of heat is evolved (temperature upto `2400^(@)C`, is generated and the reaction enthalpy is : `852" kJ mol"^(-1)`) which facilitates the reduction of `Cr_(2)O_(3)` by aluminium power.
`"Cr"_(2)"O"_(3)+2Al overset(Delta)to2Cr+Al_(2)O_(3)`