Which one of the following statements is incorrect? [JEE Main 2023, 31 Jan (Shift 2)]

Boron and Indium can be purified by zone refining method.

Van- Arkel method is used to purify tungsten.

Cast iron is obtained by melting pig iron with scrap iron and coke using hot air blast.

The malleable iron is prepared from cast iron by oxidising impurities in a reverberatory furnace