明延鉱山

抄録

The Akenobe Mine is located in the central part of Hyogo Prefecture some 150km west from the ancient capital of Kyoto. Access is by highway from Himeji city on the Pacific side and from the town of Yohka, where is the nearest National Railway station on the San-in Line.
The history of the mine goes back to the early 9th century when the first discovery of the deposit was reported. Modern mechanized operation was commenced in 1896 under the management of Mitsubishi with the introduction of a western technology.
Since cassiterite in the are was found in 1909, the Akenobe Mine has been in operation as a leading tin producer in Japan. The total are mined to date is estimated to 16 million tons with average grades of 1.01% Cu, 1.48% Zn, and 0.41% Sn
The Akenobe deposits are of typical polymetallic xenothermal vein-typeproducing tin, tungsten, copper, zinc, silver and gold. More than are hundred veins are distributed in the area of about 9.0km², with a vertical extension of 1, 020m. The distri-b ution of are minerals shows a remarkable zoning with age.
In the underground mining, cut-and- fill stopirig method is adopted and mill tailings are used for backfill in the stopes. Waste rock from the cross cut is also used in some areas where waste is hard to hoist up to the surface.
Recently trackless mining has been introduced to the new development work in Chiemon area.