②海中に投入される集鉱試験機2

 

Does your heart race when you hear adventures about seeking gold and silver at the bottom of the sea? Such stories might soon become reality.

 

The Ministry of Economy, Trade and Industry (METI) and the Japan Oil, Gas and Metals National Corporation (JOGMEC) announced in September that their experiment to stably draw mineral ores from the ocean floor was a record-breaking success. They plan for the mineral ores to become commercialized in the latter half of 2018.

 

 

As a country surrounded by sea, and with one of the largest exclusive economic zones (EEZ) in the world, Japan is seeing a dream come true in the development of domestic resources. If commercialization is realized, Japan will no longer have to be complaisant in resources diplomacy. But how do we know that this won’t be a short-lived dream?

 

Series of Excavation

 

The experiment in question involved successively drawing up large amounts of mineral ores from hydrothermal mineral deposits. These are formed when water heated by magma erupts from the ocean floor, and the metal in the seawater cools and solidifies. These mineral ores contain large amounts of rare metals, such as gold, copper, and zinc—an essential ingredient for galvanized iron used for bicycles, for example.

 

The experiment was conducted by JOGMEC from mid-August until the end of September in Okinawan waters. An excavator was lowered 1,600 meters into the water, which was then used to break the mineral ores into 3-cm pieces. The pieces were then drawn up using a submersible pump.

 

 

The challenge was drawing up the seawater containing the heavy mineral ores without clogging the pump. In the experiment, excavations were carried out 16 times, once every 10 minutes. A total of 16.4 tons were drawn up. It is thought that the mineral ores contain 7–8% of mineral resources.

 

Until now, there were no means of drawing up mineral ores from the hydrothermal mineral deposits. The only option was to use a submarine to excavate mineral ores, and only tentatively.

 

The trailblazing achievement of successive excavation of mineral ores from the ocean is the culmination of the advanced extraction technology developed by Japanese companies. The excavator and pump were designed by Mitsubishi Heavy Industries. It also involved impressive ship handling skills, which were necessary to keep the ship still despite the ocean current.

 

 

Producing large pumps and low cost excavators are paramount when it comes to commercialization, but Japan’s technology is a cut above the rest.

 

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Deposits in Nine Locations

 

In order to determine the feasibility of commercialization in 2018, METI will be conducting investigations in other parts of the ocean to determine the amount of resources available, among other data.

 

Hydrothermal mineral deposits have been found in eight other locations aside from Okinawan waters, such as the sea near the Bonin Islands.

 

 

It is said that there are 7.4 million tons of mineral resources in Izena Caldron, located on the seafloor approximately 110 kilometers deep, northwest of Okinawa Island. That amount of resources us equal to the domestic annual consumption.

 

Japan’s EEZ is the sixth largest in the world. In addition to hydrothermal mineral deposits, it is said that essential marine resources lie in deeper seas. For example, cobalt-rich crusts are clusters of rocks that contain large amounts of rare metals, such as cobalt, nickel, and platinum. Manganese nodules are round rocks that also contain rare metals.

 

These are also expected to contain rare-earth elements, which are ingredients used in the magnets of high-performance motors. Mud-containing rare earth has also been discovered around Minami-Torishima Island, located at the easternmost tip of Japan, approximately 1800 kilometers from Honshu.

 

 

Hiroshige Sekō, the Minister of Economy, Trade and Industry, said in a press conference: “We expect the presence of mineral ores in the ocean around Japan, of an amount that is greater than the domestic annual consumption. Based on the success of the experiment, we aim to start the development of domestic natural resources in order to lead the country in securing a stable supply of mineral resources.”

 

Hurdles to Overcome

 

However, massive hurdles must first be overcome before marine resources on the ocean floor can be successfully exploited.

 

The first hurdle is the sheer depth involved. Even the shallower hydrothermal mineral deposits are located 700 to 2,000 meters under water. Manganese nodules and rare earth sediments are located at a depth of 4,000 to 6,000 meters, and the cobalt-rich crusts are located at the bottom of deep ocean, 800 to 5,500 meters deep. The excavators are indispensable for the hydrothermal mineral deposits, but an even more sophisticated level of pressure-resistance and sealability will be imperative.

 

Furthermore, the beneficiation process, which separates impurities from the useful mineral ores, will be different for mineral ores found on land and mineral ores found in the sea. A beneficiation process that is suitable for mineral ores in the sea must be developed.  

 

Another issue is that most domestic mines have closed down, along with the beneficiation facilities.

 

“If we compare our situation to hiking, it’s like we finally got all our equipment together and are now standing at the base of the mountain,” Sekō said.

 

Even if the exploitation of marine resources can be actualized, it won’t be happening for the next few decades. However, merely having domestic resources gives Japan a powerful negotiation advantage in what a member of the press calls the “fast-pace race of resource diplomacy.”

 

In September 2010, a patrol vessel of the Japan Coast Guard collided with a Chinese fishing trawler off the coast of Senkaku Islands (Ishigaki, Okinawa). When the Japan Coast Guard detained the captain of the fishing trawler, tensions rose between China and Japan, and the Chinese government blocked exports of rare-earth elements to Japan. Although Japan was aiming to develop motors that didn’t need rare-earth elements at the time, having domestic resources can empower Japan to confront China more assertively.

 

 

“I feel like we have overcome the first hurdle,” said the executive of METI, his countenance showing relief.

 

The executive director of JOGMEC, Takafumi Tsujimoto, gives his stamp of approval on the “turning point of the development of marine resources.”

 

Japan is not a country without its resources. The light of the country’s hope shines in the darkness of the deep ocean.

 

 

Katsutoshi Takagi  is a staff writer of the Sankei Shimbun, Department of Economic news.

 

 

(Click here to read the original article in Japanese.)

 

 

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