The HIsarna ironmaking process is a smelting reduction process for iron making in which iron ore is processed almost directly into liquid iron (pig iron). The process combines two process units, the Cyclone Converter Furnace (CCF) for ore melting and pre-reduction and a Smelting Reduction Vessel (SRV) where the final reduction stage to liquid iron takes place. The process does not require the manufacturing of iron ore agglomerates such as pellets and sinter, nor the production of coke, which are necessary for the blast furnace process. Without these steps, the HIsarna process is more energy-efficient and has a lower carbon footprint than traditional ironmaking processes. In 2018 Tata Steel announced it has demonstrated that more than 50% CO2 emission reduction is possible with HIsarna technology, without the need for carbon capture technology. The HIsarna process was developed in stages and with pauses at Koninklijke Hoogovens / Corus IJmuiden / Tata Steel IJmuiden, starting in 1986. The final stages were made possible through the Ultra-Low Carbon Dioxide Steelmaking (ULCOS) consortium and cooperation between former Corus (now Tata Steel) and the Rio Tinto Group. The latter contributed their HIsmelt (short for "high intensity smelting") technology to the final design of the installation, prompting the name HIsarna for the process ("HI" from "high intensity" and "sarna" from Isarna, a Celtic word for iron). HIsarna is considered one of the most promising developments in reducing CO2 emissions from the steel industry.
History The very first attempts at applying cyclone oven technology in the reduction of iron ore took place at Koninklijke Hoogovens in the 1960s. Cyclone technology had already been used successfully in different industrial, chemical processes and designers at Hoogovens thought it might be a strategy for improvement for their process. However, at the time they could not get it to work properly and the experiment was quickly abandoned. The first serious revival came in 1986, when Hoogovens sought a method of producing steel without having to produce iron ore agglomerates such as pellets and sinter. At that time the desire was mostly a cost-cutting measure in order to make the process cheaper in trying economic times. The trying times did not last however and the project was put on the back burner until the early 1990s. By the early 1990s the availability of cokes was becoming limited due to many of the major coking facilities in the West that produced cokes from coal reaching the end of their economic life. Heavy environmental restrictions made it unattractive to build new facilities, so steel producers sought ways to reduce the need for cokes; Hoogovens started putting more effort into the cyclone technology as a solution to this problem and a test facility for the cyclone part proved capable of producing twenty tons of pig iron per hour. The rest of the process didn't work very well though, so when steel producers massively moved to replace part of the coke by powdered coal injection and China started mass-producing cokes, the project lost momentum again. The steep drop in prices of commodities around 1999 caused the project to be halted. In 2004 however, the European Union brought pressure on the steel industry to reduce its carbon footprint; the ULCOS consortium was founded as a result and in the period 2005–2007 the cyclone technology was selected as one of four high-potential technologies. A theoretical answer was found to the earlier problems of the post-cyclone part of the cyclone furnace in the form of a Smelting Reduction Vessel and the Rio Tinto Group had industrial-scale experience with the required process, called HIsmelt. An agreement between them and ULCOS added the HIsmelt technology to the cyclone furnace and the result was the HIsarna process. In 2017 Tata Steel obtained the smelter IP rights from Rio Tinto, now fully owning all HIsarna IP.
Pilot plant
In 2010 the HIsarna pilot plant was constructed at Tata Steel IJmuiden. The pilot plant has a capacity of producing 65,000 tons of pig iron per year. A first campaign of experiments was completed in spring 2011, which was followed by three more successful experimental campaigns. The second and third campaign were co-financed by the Research Fund for Coal and Steel (RFCS). The fourth campaign finished in June 2014. The fifth campaign started in the autumn of 2017. This project was part funded by the Horizon 2020 Framework Programme from the EU, as part of the second Sustainable Industry Low Carbon (SILC-II) funding round. In 2021 the sixth HIsarna campaign was started. By 2023 the pilot plant had produced a total of 12 000 tonnes of liquid hot metal and the longest continuous run was 19.5 days. In the spring of 2026 it was reported that the pilot plant had undergone several significant upgrades improving productivity, introducing injection of natural gas as part replacement for coal injection and the installation of thermal imaging inside the Smelting Reduction Vessel. In the same publication it is reported that the total production of liquid hot metal was 19 000 tonnes with a daily record of 160 tonnes and a coal rate of 726 kg per tonne of liquid metal.
Process
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