2Al(s)  +  6HCl(aq) -->  2AlCl3(aq)  +  3H2(g)

Cu(s)  +  n HCl(aq)  -x->  No Reaction
Removal of Excess Reducing Agent
Once you have ensured that the aluminum is in excess (some aluminum will be floating on the surface), then it is time to proceed with the next step:  removal of the aluminum.
 
This is accomplished by adding HCl in excess. 

The HCl reacts with the aluminum and not the copper.