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 magneisium and barium peroxide) is used
`BaO_(2)+Mg to BaO+MgO`
During the above reaction a large amount of heat is evolved (Temprature 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)+2Aloverset(Delta)to2Cr+Al_(2)O_(3)`