Which of the following option are correct?
(i) Cast iron is obtained by remelting pig iron with scrap iron and coke
using hot air blast.
(ii) In the extraction of silver, silver is extracted as cationic complex.
(iii) Nickel is purified by zone refining.
(iv) Zr and Ti are purified by van Arkel method
Option (i) and (iv) are the answers.