Hafna Mill - Gwydyr Forest, Nr Llanrwst, Conwy, North Wales, UK - Water Mills on Waymarking.com

The following website describes the mill with the information board text included:visit link

'Around 1615 Sir John Wynn, 1st Baronet, had samples of lead ore from his Gwydir Estate analysed, which then resulted in organised mining on the estate starting some five years later. Mining activity in the area, in a total of around 21 mines, was to continue for some 300 years.

There are records of the Hafna lead mine being reworked from 1819 by the landowner Edward Lloyd of the Plas-yn-Cefn Estate. The first mill buildings here were built in 1879 and the mine finally closed around 1915.

The Hafna Mill Complex was originally constructed in 1879 and underwent a number of changes before working ceased around 1915. Today it is still possible to identify at least three constructional phases from the surviving remains.

The main area of the site comprises the mill itself which is built on four floors. It was here that the ore was crushed, sorted and concentrated prior to smelting.

All mechanical processes at the mill were originally driven by a waterwheel, later replaced by a gas engine.

Ore was brought into the mill from the mine via an adit and a shaft located just beyond the top floor of the mill. The ore was stored in bins and then sorted by hand on the upper, first floor of the mill. From there it was mechanically crushed on the second floor. The crushed and partially separated ore was then jigged and the larger pieces of pure ore removed for smelting. The remaining material was then buddled, a type of gravity separation process, to isolate the smaller particles of pure ore. The remains of a circular buddle pit can be seen protruding from under a later concrete floor that housed the oil flotation tanks which came to replace the earlier separation methods. The waste material from all stages of the milling process was taken by tram through tunnels on each floor to be dumped. The fine residues from the mill were collected in a large slime pit which was occasionally dug out and re-processed.

Smelting House

Of all the mine mill sites found within the Gwydyr Forest Park, Hafna is unique in having its own smelt house, built in the 1880s.

The remains of the smelt house and adjacent blowing house can be seen behind the slime pit on the third floor level of the mill. The blowing house once housed a pair of mechanically operated bellows that generated air via pipes for the smelting hearth, located below the flue arch. The smelter would have been a relatively simple affair, probably a reverberatory furnace of Flintshire type.

Ore and fuel would have been mixed together and raked in the furnace, effectively roasting the ore. As the temperature was increased the molten metal would flow to the bottom of the furnace, from where it was tapped.

Because of the toxic fumes from smelting the furnace chimney was set above and away from the mill. The two were linked by a long flue, the line of which can still be seen.

— Forestry Commission Wales interpretive panels'