DO NOT HEAT GALENA, OR ANY SILVER ORE...unless you need a lead fix.
there is a silver mine here in arizona i pick up ore off the tailings...one can place this ore on a burner, and sweat silver and lead out of the rock...a friend, discharged from the navy for lead poisoning....took a piece home...set it on the bburner in the kitchen...several weeks later after he was discharged from the hospitial....he was real mad at me...even though i told him not too.
the fumes will kill you if you are a sensitive, and make you ill and stupid if you are normal.
it is nasty, not recomended method for removing silver from the rock...