【廃墟・遺跡】新裏日本百景　クロム産業を支えた天空の要塞　4K　#廃鉱山

Located in Nichinan Town, Hino District, Tottori Prefecture, near the border between Tottori and Okayama, the site of the former Wakamatsu Mine is an industrial heritage site that once boasted one of Japan’s highest chromite ore production volumes. Although it has now ceased operations and only the ruins remain in the quiet mountains, its history is rich with stories that supported Japan’s modernization and postwar reconstruction. I visited in the autumn of 2020, amidst the colorful mountains. Guided by a staff member from the town of Nichinan, which oversees the site, I was able to spend a valuable time there. It appears that due to various circumstances, such as the collapse of buildings, the site is currently closed to visitors. This is the equipment used to load ore onto trucks for shipment—it is called a hopper. Far beyond what one might imagine from the appearance of the first building, the facility stretched deep into the mountainside. Climbing the slope along a side path to the entrance of the ore processing plant Viewing the site from the bottom means tracing the process in reverse. In the ore processing plant, the section where the roof had collapsed appeared to have sustained severe damage. However, stepping inside, I found numerous pieces of ore processing equipment preserved in such pristine condition that it took my breath away. This area is the lowest level of the mining facility, where the final sorting of the ore was apparently carried out using a density separator known as a “Hartsjigger.” It appears that a considerable amount of water was required during operation, and even now, large amounts of water were flowing out of partially damaged pipes. As a result, the interior of the processing plant was constantly filled with the sound of water flowing like a waterfall. The sight of the pillars and piping crisscrossing the space was truly spectacular. The Wakamatsu Mine was discovered in 1899 (Meiji 32), and subsequently, full-scale mining began by Nippon Chrome Industry Co., Ltd. (one of the predecessors of Nippon Denko) began full-scale mining operations. From the Taisho era through the early Showa era, the Wakamatsu Mine produced ore of such high quality and quantity that it was hailed as “the finest chromium mine in the Orient.” Since chromium was an extremely important strategic material—used as a raw material for stainless steel and as an additive for special steels in the military industry— its production was strongly prioritized as a national policy, particularly during World War II. At its peak, a massive ore processing plant and administrative offices were established deep within the mountains, and it is said the area bustled with activity that belied its remote, deep-mountain location. Even after the war, the mine continued operations as a source of raw materials for the steel industry, which supported Japan’s period of rapid economic growth. The reason the Wakamatsu Mine developed to such an extent appears to lie in the region’s unique geological structure. The area surrounding the mine is characterized by the widespread distribution of a rock known as “serpentine.” Serpentine is formed when “peridotite,” a rock found deep within the Earth (in the upper mantle), reacts with water and undergoes metamorphism as it rises near the surface due to tectonic movements. Chromite is concentrated and found within this serpentine. The ore deposits at Wakamatsu Mine existed as large lens-shaped or massive ore bodies and were characterized by their exceptionally high grade (chromium content). The ruins of the processing plant, built on a slope, were where the mined ore was finely crushed and impurities were removed using differences in specific gravity. As you ascend to the upper levels, the size of the processed stones increases. This is a roll crusher, a piece of equipment used to compress and crush the ore. I wonder if they used to sort things by hand around here. The sound of water has grown fainter, indicating that we have reached a fairly high floor. Numerous tools were left behind as they were. It appeared that two buildings of different heights were connected by a conveyor belt. Let’s look inside from the lower building. Is this massive air vent intended to cool the ore? Up to the second floor of the lower building. I carefully walk along the side of the conveyor belt toward the building across from me. On to another facility. Around here, the sunlight is much stronger compared to the lower levels.