... such metals as copper, gold ,silver, zinc, aluminium , lead .etc 2 . Efficient Graphite crucible have four different main type .Item ... no same place . they are different crucible , different using .If FOR metling copper, gold ,silver, zinc, aluminium , lead , cast iron ... saving ,Environmental protection . DurableWe provide Item 1 . 3 . 4 crucible except Item 2 . silver smelting crucible (sic graphite ...