Monument record MDR8430 - Darley Smelter, Oldfield Lane, South Darley

The most recent developments in lead smelting have taken place at the Darley Smelter on the old Mill Close mine site. Here, at a plant opened to replace Lea, ore hearths (of various types) and reverberatories have been used, whilst today the smelter is dominated by a tall chimney to dispose of fumes from a blast furnace. Both Lea and Darley have one very characteristic feature of lead smelting which now is properly within the province of industrial archaeology - that is the large lunar-crater-like heaps, which are the dumps of calcium sulphate formed by condensing (absorbing) sulphur dioxide fumes in lime water. The resultant slurry was piped to a pond on top of the heap, where the solid residue settled, whilst the liquor was re-used. The pond was kept open by sludging, so as to build up the side - thus forming the crater. (1) The Darley smelter was established by Mill Close Mines in 1934 and was bought in 1941 by JH J Enthoven & Sons, a London-based lead producer. A new smelter was built between 1984 and 1986; the site continues in use today, with an increasing focus on battery recycling. (3)