1. A process for removing in situ a first chemically reactive element from a generally insoluble gangue material in an ore bearing formation, comprising the steps of drilling a borehole into said ore formation, introducing a selected leaching solution containing a second chemically reactive element into said ore formation through said borehole, passing an electric current through said leaching solution and said ore formation for chemically reacting said first and second chemically reactive elements which remain in solution in said leaching solution and withdrawing said leaching solution and said first chemically reactive element through said borehole.