Old Millclose Mine is a lead mine, located near Darley Bridge and Wensley, Derbyshire.
It is unknown how old the mine is, but it was worked commercially through the 16th and 17th centuries. When it was operational, five soughs, underground channels for draining water out of a mine, were required to drain Old Millclose as the workings went deep under the shale, these were drilled between 1658 and 1678. Old Millclose also contained two underground water wheels and in 1782, an engine was installed in the workings. Yatestoop sough is 4km long and reaches Coast Rake at Elton.
The mine was running out of ore by the late 1850s and was due to close, but fortunately a rich ore vein was found, branching out many different ways. This new discovery opened up caverns containing huge quantities of sphalerite, zinc ore, and galena, lead ore and were very pure. Often, it took very little effort to mine them as they were of sedimentary origin. Underground water courses had eroded mineral veins elsewhere. The detritus was carried along underground and deposited where the flow slowed down in larger caverns. Fantastic crystals of calcite and galena were discovered, up to 30 cm in size.
The engine house was built in 1859 - 60 by Edward Wass, who owned Lea Lead Works and invested in Millclose. It housed a Cornish engine, made by Thornewill and Warham of Burton-on-Trent, to pump water from the mine via the Watts engine shaft nearby. The engine was in use until the early 1870s, when it was moved to the new Millclose mine, some 450m north east.
The miners hit an underground lake or river in 1938. causing the mine to flood, halting mineral production. It took many months to pump the mine clear, however, Millclose mine was finally closed in 1940, as there was still over 2000 litres of water per minute pouring in.
Today the engine house survives as a ruin, with foundations and one standing wall, to the east, visible. This is the bob wall, which was thicker than the others in order to support the beam of the pumping engine. Standing to a height of 9m, it is built of substantial gritstone ashlar 1.5m thick, pierced by two main openings, an arched plug door for access to external condensing equipment, and a smaller opening below it, through which steam exhaust pipes ran. A larger arched opening would have originally existed above these, which accommodated the pivoting beam of the engine. The remaining structures are listed.
Nearby are the foundations of a boiler house, a winding engine house and a chimney. East of the engine house is the stone-lined shaft, now capped and covered with a grille.
Millclose mine produced over half a million tons of lead ore and almost 100,000 tons of zinc ore in its century of life. About half of the lead tonnage was actually produced in the 1920s with a further 140,000 tons by re-working the spoil heaps in the 1930s and 40s.
There are shafts accessible, leading to over ten miles of surveyed passages, including a complete underground blacksmiths shop with bellows, hearth and tools in situ. Large spoil heaps from this mine can be seen opposite the factory close by, but these have been extensively reworked to extract fluorspar. The whole area is contaminated with lead and is unsuitable for grazing. The current owners have planted trees on large areas of the contaminated land.