Milling Area

The milling area at Ashio Copper Mine occupies one of the central levels of the processing plant, a long industrial hall with ball mills set along the floor and the supporting steelwork of the conveyors and chutes rising overhead. The hall is lit from one side by a row of large industrial windows facing the valley, the panes mostly intact but coated in decades of dust. The floor is concrete, stained with the pale grey ore residue that escaped from the mills over the years. The mill drums, their steel bodies darker than the rest of the room, sit between drive pedestals at one end and discharge housings at the other. Overhead, the ductwork carries dust-laden air toward the extraction fans on the far wall.

The milling area was the second major processing stage at Ashio, taking the crushed ore from the receiving hoppers and reducing it to the fineness required for the flotation circuit downstream. The ball mills here ran almost continuously through the working shifts under the Furukawa modernisation from 1877 onwards. The Excavation Department closed in 1973, and the milling area shut down with the rest of the plant. Some of the heavier machinery has been disturbed in the years since, but most of the major fittings have stayed in place. The hall remains essentially as it was at closure.