新しい中国の鉄生産方法が時間を秒に変える

鉄は依然として金属の王者

When discussing manufacturing innovation, the attention tends to be concentrated on high tech (ロボティクス, 3Dプリンティング) or on rare metals and materials, like タングステン, チタン, ロジウム, etc. (follow the links for detailed investment reports for each).

結局のところ、これらの進歩は重要であるものの、私たちが使用する材料の大部分ははるかに単純であり、現代生活にとって鉄ほど不可欠な金属はありません。

鉄と鋼は、インフラ（橋梁、鉄筋コンクリートなど）、物流・輸送（自動車、鉄道、列車、港湾、船舶）および無数の産業用途（配管、貯蔵タンク、炉など）に大量に必要とされる重要な材料です。

鉄酸化物は赤鉄鉱、褐鉄鉱、磁鉄鉱、黄鉄鉱、黄鉄鉱などの鉱物から得られ、現在精錬される金属の約90％は鉄です。

出典: FTM Machinery

Luckily, iron is very abundant on Earth (5% of the Earth’s crust by weight) and in the universe at large. However, turning it into a usable form can be a very energy-intensive and time-consuming process. So it is big news that Chinese researchers have announced that they found a method to boost a central step in iron making, with productivity up 3,600 fold.

鉄はどのように作られるのか？

Pure iron is produced from iron-rich ore, which is turned into purer metal through the process of smelting.

古代の原始的で低温の溶鉱炉から、12世紀以降に中世や近代にかけて、1,400〜1,500℃（2,550〜2,700°F）という高温でより効率的に鉄を生産できる高度な炉が開発されました。この熱く精錬された鉄はしばしば直接製鋼所へ送られ、熱ロスを削減します。

現代の方法でも、転炉での鉄の精錬は5〜6時間かかる長いプロセスです。そのため、全工程で高温を維持する必要があり、通常は石炭または天然ガスで行われるため、エネルギー消費が非常に大きくなります。

このことは、鉄と鋼の生産が化石燃料の大きな消費者であり、同時に温室効果ガスの大量排出源でもあることを意味します。鉄と鋼の生産は、全CO2排出量の約7％を占め、EU全体の排出量を上回ります。

現在、世界の鉄鋼生産の大部分は中国にあり、世界全体の55％以上を占め、次いでインドが7％を占めています。

出典: GMK Center

Both China and India mostly use coal to produce iron and steel, making their production processes particularly large emitters of CO2.

石炭の代わりに水素？

In order to replace coal, green steel manufacturing methods have been proposed, with the best candidate being using hydrogen instead of coal to reach the required high temperatures.

The problem is that so far, only very high-quality iron ore can be used with hydrogen. Cheaper ore with lower iron content would be required to compensate for the higher costs of hydrogen compared to coal.

This is true, at least in blast furnaces, but a new process, called flash iron smelting, could be different.

フラッシュアイアン

The process was described by Chinese researcher Professor Zhang Wenhai and his team in a paper published in the peer-reviewed journal Nonferrous Metals. It claims to complete the iron-making process in just three to six seconds, compared to the five to six hours required by traditional blast furnaces.

The key idea is that instead of using small pellets of iron ore, it grinds it into a dust of very small particles. This allows for the reaction turning iron ore into pure iron to be near instantaneous, more akin to an explosion than a slow melting of the ore.

This results in a flash oxidation of the particle in a few seconds.

出典: MDPI

アイアン・ヴォルテックス・ランス

Reducing the iron ore into fine particles is not a very difficult step or complex technology. What is a lot more tricky is injecting it into the smelter safely and efficiently.

To solve this issue, Pr. Zhang’s team has developed a vortex lance that can inject 450 tonnes of iron ore particles per hour. A reactor equipped with three such lances produces 7.11 million tonnes of iron annually.

More importantly, this technology is not just a laboratory experiment but is already entering commercial production.

This has not been an overnight success, but the result of long-term efforts started in 2013 when Zhang’s team obtained a patent for a flash smelting technology capable of directly producing liquid iron. It took ten years to refine the method and scale it up to a pilot plant, demonstrating that safe, large-scale production was possible.

出典: News.com.au

It should also be noted that Professor Zhang has experience in changing metallurgical science. He revolutionized copper production with a similar flash smelting technique he applied to copper in the 1970s. He was handed the first prize of the National Science and Technology Progress Award in 2000 and elected to the Chinese Academy of Engineering in 2003.

中国の戦略的目標

炭素排出

As China is the global leader in steel making, the over-reliance of this process on coal has hindered the country’s ambitions to reduce carbon emissions. It also makes its industry highly reliant on imported coal, especially from Australia.

So, China has a strong incentive to develop alternative methods and deploy them quickly, especially if it allows the use of hydrogen instead. Combined with its role as a leader in green energy production, China is in a good place to become the leader in green steel production.

世界の鉄市場を再構築するか？

Another thing that makes this method unique is that it works very well for low or medium-yield ores. This could completely reshape the global iron markets.

Currently, high-quality, iron-rich ore from Australia is the primary supply of iron to Chinese smelters and steel plants.

出典: S&P Global

If flash iron smelting with hydrogen is used to replace coal-powered blast furnaces, the domestic supply of lower-quality iron ore could be used instead.

The relationship between China and Australia has steadily degraded in the past decade, despite China’s dependence on Australian iron. For example, in the 2020 trade war with Australia, iron was excluded from sanctions due to the country’s high dependence on it. So, solving this vulnerability could be seen as a strategic imperative by China, regardless of the economic calculus.

鉄鉱山会社

ヴァーレ

A decrease in iron smelting costs and carbon emissions could make steel an even more popular material than it is today. When it comes to mining, scale and good geology are everything, with low production costs allowing for higher profits and safety during downturns, which are inevitable in commodity markets.

The Brazilian company Vale is the largest producer of iron and nickel in the world, with a total of 323-330 million tons produced in 2024.

The company is also a producer of metals relevant to the “energy transitions,” like copper. While these metals might be important for the future, for now, iron is the core of the company.

The company used to be more diversified but re-centered around iron in recent years, having divested $2B worth of various other metal mines and other commodities like palm oil.

出典: Vale

大規模資産基盤

Vale qualifies as a medium-sized utility company, operating its own railroad, trains, harbors, and ships to transport ore from extraction to delivery to customers.

It also produces a lot of its own energy, as it operates in remote regions and cannot depend on the Brazilian government to do its job properly, especially considering its massive power requirements.

This was commonly done with hydropower, as the business of mining is not so different from hydropower construction (earthworks, digging rock with explosives, massive amounts of concrete, heavy machinery, mega construction projects, managing rain, etc.).

These infrastructures are complemented by the company’s R&D center, laboratories, hundreds of geologists, training centers, etc.

過去の負債を克服する

One big risk with a massive mining company like Vale is a massive accident causing massive damage.

This is what happened in 2015, with a massive disaster that occurred after a Vale-built dam collapsed. And then a similar incident in 2019.

The flooding caused Brazil’s worst environmental disaster to date, killed 19 people, and affected 39 municipalities across two states, burying them in mining waste products.

Since then, a lot of similar dams have been repaired and/or improved to avoid another catastrophe during the rainy season.

The company has also changed how it operates, having invested $2.5B in four filtration plants to create dry tailing (the crushed rock, dust, and mud) instead of wet tailing requiring dams. So in the future, iron mining activity will no longer create the sort of waste that requires dams at all.

The company is also actively repairing its image, insisting on how its mining activity, combined with a large natural reserve financed by the company, is a major contributor in preserving the Brazilian rainforest, others turned into pasturelands in the region.

出典: Vale

全体として、ヴァーレは過去の環境災害による問題を克服し、ブラジルで最も価値のある資産の一つ、そして世界、特に中国にとっての主要な鉄供給者へと変貌を遂げています。中国はBRICS商業ネットワークを通じてブラジルとより深い関係を築いています。