Removing copper corrosion from granite

I performed a conservation treatment on a Civil War monument that
sits on an eleven foot high granite pedestal. The runoff from the
corroded bronze stained the granite. The Veterans of Foreign Wars
(VFW) post that takes care of the memorial contracted the cleaning
of the granite to a monument (grave stones) firm. They used muriatic
acid in water diluted 1 cup/1 gallon water sprayed under pressure
(psi unknown) and rinsed with water afterwards. The VFW
representative informed me that the stains are still there. They've
asked me to investigate and advise them on this matter. I found
references about cleaning stone, marble etc. but none of them
addressed the green runoff from bronzes specifically. Could anyone
guide me on this one? Thanks

Isabel M Coryat
Conservation Dept.
Coryat Casting Co
3346 Route 9G
Rhinebeck NY 12572


                                  ***
                  Conservation DistList Instance 16:25
                Distributed: Wednesday, October 2, 2002
                       Message Id: cdl-16-25-015
                                  ***