A cutting-edge facility of the time due to its productivity and technology as the quintessential domestic mine

The Kitazawa Flotation Plant consists of the remains of a huge industrial complex built to extract the minerals excavated from the Sado gold mines from the 19th century into the 20th century. Going into operation in 1869, it modernized by promptly incorporating the latest Western technology, so that by 1937 when Japan was on the cusp of war, massive capital investment for a boost in productivity was launched to develop the complex into a facility which could boast a scale that was tops in East Asia. However, following the war, the Sado gold mines were downsized and finally closed down in 1989 after which they remained abandoned for about 20 years. Still the complex retained the concentrator, thickener, ink lines, generator, factory and other parts which were praised for their value so that it was opened to the public as an important industrial heritage site. The original generator plant is now a photo gallery displaying numerous materials so that visitors can see examples such as the workers from those days.

The floatation plant given huge capital investment

The flotation plant measures about 115m east to west/80m north to south, and is a large facility situated on the side of a hill. The plant had an important role as the part of the final processing in sorting out the mined ore during gold and silver production. It processed 30,000 tonnes of minerals per month in 1937; this capacity increased to 50,000 tonnes/month the following year with expansion into a large-scale facility.

The 50m thickener, a gigantic concentrating apparatus resembling a shrine

One of the buildings in the complex is the 50m thickener which is the remains of a huge disc-shaped building where the sludgy ore which included gold and silver was separated from water. The massive thickener was completed in 1940. With this, the largest flotation plant in East Asia was realized. Currently, the building is covered in weeds, and its abandoned appearance evokes an ancient Roman temple bespeaking of the prosperity of the past.