Which of the following is not the correct match?

Extraction of gold and silver involves leaching the metal with CN−.

Zone-refining process is used when metals are required in very high purity, for specific application. For example, pure Si and Ge are used in semiconductors.

Liquation process is used for the purification of the metal, which itself is readily fusible, but the impurities present in it are not, used for the purification of Sn and Zn, and for removing Pb from Zn-Ag alloy.

Van Arkel method is used for refining Zirconium or Titanium.