A new iron making technology developed in China is set to significantly impact the global steel industry. Developed after more than 10 years of research, this method injects finely ground iron ore powder into a very hot furnace, causing an “explosive chemical reaction”, according to the engineers. The result is a continuous flow of high-purity iron that forms as bright red, glowing liquid droplets that accumulate at the base of the furnace, ready for direct casting or one-step steel-making.
Process takes just three to six seconds
The flash iron making method, as detailed by Professor Zhang Wenhai and his team in a paper published in the peer-reviewed journal Nonferrous Metals last month, can complete the iron making process in just three to six seconds, compared to the five to six hours required by traditional blast furnaces.
This represents a 3,600-fold or more increase in speed. The new method also performs exceptionally well with low or medium-yield ores, which are plentiful in China, according to the researchers, the South China Morning Post reported.
China currently relies on high-yield ores and spends a substantial amount importing them from Australia, Brazil, and Africa. According to Zhang and his colleagues, the new technology could improve energy use efficiency in China’s steel industry by over one-third. Additionally, by eliminating the need for coal entirely, it would help the steel industry achieve the goal of near-zero carbon dioxide emissions.
Blast furnace reliance hampers targets
China’s steel production capacity already exceeds the combined output of the rest of the world, providing it with a significant advantage in key industries like high-speed rail, shipbuilding, and car manufacturing. However, its reliance on blast furnace smelting processes, which consume large quantities of coke derived from coal, poses a significant challenge to achieving China’s ambitious carbon reduction goals.
One of the major technical hurdles for flash iron making is the ore-spraying lance, which must effectively disperse iron ore in a high-temperature, highly reducible tower space with a large specific surface area to initiate the necessary chemical reaction.
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. As per the paper, the lance “has already entered commercial production.”
Although the concept of applying this process to iron making originated in the US, it was Zhang’s team that developed a flash smelting technology capable of directly producing liquid iron. They obtained a patent in 2013 and spent the next decade refining the method. “The laboratory and pilot tests have confirmed the feasibility of this process,” Zhang noted. Government statistics reveal that the success rate for new technologies that undergo pilot testing in China exceeds 80%.
