Which metal is purified using the Mond process?

For the electrolytic refining of aluminium (Hoopes' process),the three fused layers consist of:

Bottom Layer	Middle Layer	Upper Layer

Nitriding is a process of heating steel in an atmosphere of

$TiI_{4}$ on heating gives

Which method of purification is represented by the following equation?
$Ti_{(s)} + 2I_{2(g)}$ $\xrightarrow{523 \ K} TiI_{4(g)}$ $\xrightarrow{1700 \ K} Ti_{(s)} + 2I_{2(g)}$

Which of the following pairs is incorrect?
$(a)$ Goldschmidt alumino-thermite process $-$ $Cr_2O_3$
$(b)$ MacArthur-Forrest cyanide process $-$ $Fe$
$(c)$ Mond process $-$ $Ni$
$(d)$ Van Arkel process $-$ $Au$