Monument record 1446/8/1 - Wood Mine Cobalt Works.

West Mine, and its neighbour Wood Mine were developed during Alderley Edge's most active period, 1857-1878, by James Mitchell, and Alderley Edge Mining Co. The locations of the original Wood Mine and West Mine entrances, as well as the modern ones are included within the SAM. The works were set up to process copper and lead ores and later to extract cobalt from the copper ores by the Alderley Edge Mining Company shortly before 1860. The lead works were closed in 1863. The cobalt plant ceased operation in 1864 and copper production was abandoned in 1878. In the short duration of operation of the site, 168,269 tons of copper ore had been processed and 3200 tons of fine copper metal produced. In addition almost 100 tons of lead and 11 tons of cobalt-nickel were produced. After 1878 the site lay idle until a new works was constructed, possibly at a different location, in 1914. This was sold off in 1926.

The cobalt-processing site is considered unique. Copper ore from the mines was first crushed and fed into wooded leaching tanks where the copper was removed by dissolution with HCl acid. The liquid was then put into precipitating tanks where scrap iron was added. Dissolution of the iron displaced the copper causing it to precipitate. The remaining solution contained iron, manganese, nickel and cobalt. This was concentrated and evaporated to produce a cobalt-nickel ‘speiss’, some of which was sold to manufacturers of paint or enamel. Though this site/process is of technological interest, documentary evidence suggests that a ready market for this product was never found. The surviving features from this process include the remains of the wooden dissolution and precipitation tanks (1446/7/7), the bases of furnaces for heating the cobalt solution, the foundations for the cooling tower for evaporating the cobalt solution (or possibly condensing and absorbing the HCl vapours (3)) and the beds for the steam engines that powered the process. In addition there are the remains of the ore crushing machinery (1446/7/5), tramways (1446/7/6), offices, workshops and possible workers accommodation. The workers cottages (1446/7/4) were inhabited until at least the 1950’s, but are now demolished. One cottage was dated 1747. Evidence for the mines survives in the form of the remains of pit-heads and shafts to a number of the mine entrances. Notable amongst these are the remains of the winding houses to Wood Mine (1446/8/2) and West Mine (1446/7/8), the crusher and buddling floor to Wood Mine (1446/8/2) and the dressing floors common to each mine. A number of spoil, slag and sand hills (1446/7/11 and 1446/8/3) are also present (1). (4)

<1> English Heritage, Various, Old/Original Schedule Entry (Scheduled Ancient Monuments Description), 33863 (Scheduling Record). SCH4606.

<1> English Heritage, Various, Schedule Entry (Scheduled Ancient Monuments Amendment), 33863 (Scheduling Record). SCH2950.

<2> 1998, Alderley Edge Landscape Project Archive, 63 (Unpublished Report). SCH4334.

<3> Dibben, Nigel, 2006, Personal Communiication (Written Communication). SCH4768.

<4> Timberlake, S. and Prag, A.J.N.W., 2005, The Archaeology of Alderley Edge (Book). SCH4769.