Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present?

(N/A) In the electrolytic refining of copper,the common elements present in the anode mud are selenium $(Se)$,tellurium $(Te)$,silver $(Ag)$,gold $(Au)$,platinum $(Pt)$,and antimony $(Sb)$.
These elements are less reactive than copper and are not oxidized at the anode during the electrolysis process. Consequently,they do not dissolve in the electrolyte and settle down at the bottom of the electrolytic cell as anode mud.