A team of Chinese researchers has developed a new iron-making technology that can complete smelting in as little as three seconds, a 3,600-fold increase in efficiency compared to conventional blast furnace methods, Interesting Engineering reports.

Pioneered by Professor Zhang Wenhai and his team, who published a paper in the journal Nonferrous Metals, smelting in contention blast furnaces typically takes five to six hours.

The technology uses a flash smelting method to convert iron ore into liquid metal almost instantaneously. The process involves injecting finely ground iron ore powder into a high-temperature furnace, triggering what the researchers call an “explosive chemical reaction”. This produces a continuous stream of high-purity molten iron in the form of red-hot droplets ready for casting or immediate steelmaking.

The idea of applying flash smelting to iron-making was initially suggested in the United States. But it was Zhang’s team that developed the method to the point where it is now commercially viable.

“The laboratory and pilot tests have confirmed the feasibility of this process,” Zhang said. The team secured a patent in 2013 and spent over a decade refining the technique.

According to the researchers, the flash method is especially effective with low or medium-grade iron ores, which are abundant in China. Currently, the country relies heavily on high-yield ores imported from Australia, Brazil and Africa.

Zhang’s team claims the method can improve energy efficiency in the steel sector by more than one-third and eliminate the use of coal, enabling near-zero carbon dioxide emissions. “The lance has already entered commercial production,” the researchers stated.

China produces more steel than the rest of the world combined, yet still depends largely on traditional coal-based blast furnaces. The new process could help address one of the major environmental challenges facing the country’s steel industry.

A critical component of the system is the ore-spraying lance, which disperses iron ore into the furnace’s reaction chamber. Zhang’s team has developed a vortex lance capable of injecting 450 tonnes of ore per hour. A reactor equipped with three lances can produce 7.11mn tonnes of iron per year, Interesting Engineering reported.