Making Sulphuric Acid on Copperas Hill (Background: Harrington)

In the early 19th century, sulphuric acid was manufactured on Copperas Hill, Harrington, near Workington, using iron pyrites from the coal mines there.

Copperas was so-called because of its green colour, which was thought back in the Middle Ages to come from copper.  In fact, though, copperas is iron sulphate, FeSO4 x H2O.  It was made from iron pyrites (FeS2, iron sulphide), found in association with coal, normally made just by leaving the iron pyrites exposed to weathering.  In the early days, copperas itself was the main product, much in demand as the key ingredient of iron gall ink, the black ink in normal use from medieval times until the import of Indian Ink, made from lampblack, rendered it obsolete in the 18th/19th century.  However, with the Industrial Revolution there was demand instead for another by-product of copperas or pyrites, namely sulphuric acid (H2SO4), also known as vitriol, produced by boiling the pyrites with rusty iron. 

In 1798, Joseph Dutton of Liverpool opened a copperas works on the cliff at Harrington, using pyrites from the Workington coal mines, delivered by wagonway.  The sulphuric acid, and other by-products, were then exported via the small harbour at Harrington. In 1837, the then owner, Joseph Theodore Dutton, went bankrupt, and the lease on the site was taken over by Littledale & Co. They only lasted until 1844. In 1853 Peter Ward resumed production, but the rescue did not last long, and he sold the works in 1855.  By this date, new more efficient methods of making sulphuric acid had been introduced, and there was to be no further industrial activity at Copperas Hill after 1860.

For more information, see https://www.cumbria-industries.org.uk/harrington-2/

Text by Bill Shannon

Image from https://www.lakesguides.co.uk/html/lgaz/LK36163.htm

To find out more about the history of Harrington, click here https://www.cumbriacountyhistory.org.uk/township/harrington

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 https://www.cumbriacountyhistory.org.uk/full-list-interesting-facts