Reading Pennsylvania copper plant deoxidation process

Green tree trunks thrown into molten copper baths to deoxidize — "poling the bath." Tom proposes (uncertain) that "electrolytic tough pitch" copper's name derives from the pitch resins in the trunk.

If you go through a copper plant — there's one in Reading Pennsylvania I went through once; I had a student do a thesis down there. They use green tree trunks with lots of sap. The way you get the oxygen out of the molten copper is you throw a big tree trunk into the bath. It creates a boil as all the hydrocarbons from the trunk burn off. It's called poling the bath, because you're using a telephone pole to stick in the bath. You get this froth — the hydrocarbons are deoxidizing the copper bath. I think the "tough pitch" comes from the pitch resins in the trunk. I'm not sure that's true but I seem to remember it from years ago. Some of this is sort of ancient technology.