Copperas works (original) (raw)

Copperas works were where copperas (iron(II) sulfate) was produced from pyrite in coal and iron. The history of producing green vitriol, as it was known, goes back hundreds of years in Scotland. In 1814 Steubenville, Ohio had 7 copperas producing manufacturers. Pyrite has been used since classical times to manufacture copperas. Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate.