Question

name the impurity present in the electrorefining of CU metal

Answer 1

Anode mud or slime is the impurity

Answer 2

Heya friend!!
In copper, many impurities like silica are present.

During electro refining of copper, you need copper sulphate solution (with Dil.H2SO4) as electrolyte, and thin copper sheet as cathode and impure copper as anode.
As you pass electric DC current, pure copper from the cathode gets deposited on the pure copper, thus you get pure copper. The impurities fall down the anode, which is termed as ANODE MUD.

Thanks!!