[Report] Transformation of Abandoned Mine Water... Also Used for Cement and Ski Resort Snow

Exploring Water Purification Facilities at Taebaek Hamtae Mine
Utilizing Iron-Containing Sludge as Cement Additive
High1 Resort Uses Mine Water for Snow Melting

Park Yong-hoon, head of the water purification facility at Hamtae Coal Mine, is explaining the process of treating underground mine water while pointing to the sedimentation tank. In the sedimentation tank, a scraper slowly rotates, gathering the sludge toward the center.

On the 7th, at the Hamtae Coal Mine Water Purification Facility located in Taebaek, Gangwon Province, water continuously flowed in from the adjacent Hamtae Coal Mine. It was reported that 5.29 million liters of water entered in just one day the previous day. At first glance, the water appeared clear, but it was filled with heavy metals such as iron, manganese, and arsenic. The concentration of iron in the water was 25.4 ppm, which is 13 times the permissible level (2 ppm) for clean areas. The concentration of manganese was 3.6 ppm, far exceeding the allowable limit (2 ppm).

When the Hamtae Coal Mine was closed in 1993, awareness of environmental issues was not high. The mine water flowing out from the closed mine directly entered the nearby Sodo Stream. The river was stained reddish due to various heavy metals, and the ecosystem was destroyed. Realizing the severity belatedly, the government began constructing a water purification facility. The project, which was carried out in three phases with a total investment of 11.5 billion KRW, was completed at the end of 2020.

The mine drainage entering the water purification facility is treated by adding neutralizing agents to adjust the hydrogen ion concentration (pH). The water, which initially appeared clear, reveals its true color as the ionic iron oxidizes and turns bright red. When a coagulant is added to this water, metal hydroxides clump together to form small particles.

Mine water flowing out from Hamtae coal mine is entering the adjacent water purification facility. Heavy metals such as iron are dissolved in ionic form, so it appears clear at first glance.

Afterward, the mine water is transferred to a sedimentation tank next to it, which is pond-sized with a diameter of 30 meters and a depth of 5 meters. As the scraper in the sedimentation tank slowly rotates, the metal particles in the water gather at the center to form sludge. The sludge, which contains a large amount of iron, is not simply discarded but is industrially recycled. Kim Tae-hyung, director of the Gangwon branch of the Korea Mine Reclamation Corporation, stated, “The sludge is dewatered and then supplied to nearby cement factories to be used as a raw material for cement.”

The appearance of iron ions in the mine water turning red as they oxidize.

The water filtered from heavy metals is finally passed through a filtration tank before being discharged into the Sodo Stream. On the day the reporter visited, there was no trace of the stream’s former bright red color. The pH of the discharged water was 8.4, and the concentrations of iron and manganese were recorded at 0.01 ppm and 0.04 ppm, respectively. In the management building, goldfish were being raised using the discharged water. It is said that otters, which only live in clean water, have also visited this place. Park Yong-hoon, head of the Hamtae Water Purification Facility, explained, “It takes about two days to treat the contaminated water from inflow to discharge.”

Heavy metal sludge filtered from mine tunnel water is sent to cement factories after moisture is removed.

The purified mine water is also used elsewhere ? at ski resorts. On the 8th, the High1 Resort in Jeongseon, Gangwon Province, was bustling with skiers from early morning as it marked its opening day. The artificial snow on the slopes where they ski down was made using the purified mine water.

The mine water from the nearby closed mine area is purified at a snowmaking water treatment plant and then supplied to the Mureung Dam through the Korea Mine Reclamation Corporation’s reverse osmosis facility. High1 Resort draws water from Mureung Dam to use as snowmaking water (secondary treated water) and water for the water park (tertiary treated water). The resort uses an average of 3,000 tons of water per day during the ski season. Because mine water is utilized, artificial snow can be made without worrying about water shortages even during winter droughts.

Coal was the main energy source in Korean society until the 1960s and 1970s. The coal mines, which had played a driving role in national industrial development, were closed one after another in the 1980s following the energy transition policy to oil. As numerous mines were closed, mining damage issues arose in mining areas, such as mine drainage contaminated with heavy metals slowly leaking from abandoned mine openings. If mine drainage is not treated promptly, it pollutes nearby water and soil, leading to ecosystem destruction.

The Korea Mine Reclamation Corporation monitors 505 sites across 305 mines nationwide. According to the survey results, pollution was confirmed at 189 mines. Among these, purification facilities have been installed at 48 mines (59 facilities) to treat mine drainage. Plans to implement projects are being considered for the remaining 141 mines (169 pollution sites).

Some closed coal mines are being transformed into complex cultural facilities. The site of the former Dongwon Coal Mine Sabuk Mining Office, the largest private coal mine in Korea, has been under development as a coal mine cultural park since August.

Perspective view of the Coal Mine Culture Park under construction on the Sabuk coal mine site by Kangwon Land. (Photo by Kangwon Land)

Gangwon Land is promoting a project to develop the former Sabuk Mining Office facilities into a coal mine cultural park that encompasses exhibitions, experiences, and parks. The goal is to complete construction by the end of next year and open in early 2025.

Interior view of the former Dongwon Tanjwa Sabuk Mining Office, currently being developed into a coal mine culture park.

The exterior will be designed as a modern building, but the interior spaces such as the changing rooms, laundry rooms, showers, restrooms, offices, connecting corridors, and hoisting rooms used by workers in the past will be preserved as much as possible during construction. More than 65,000 artifacts used by the former Sabuk Mining Office workers will also be exhibited here.

This content was produced with the assistance of AI translation services.