Solemnly committed at the General debate of the 75th session of the United Nations General Assembly on 22 September 2020:China will increase its contribution of state funding,CO2 emissions should peak by 2030,Working towards carbon neutrality by 2060，To achieve carbon neutrality and dual carbon by 2060 is the solemn commitment of the Chinese government to the international community, and it is also an inevitable strategic goal for the development of our steel indust. In general, the steel industry energy saving and carbon reduction, cost reduction and efficiency are the main ways: 1. Eliminate backwardness, save energy and improve energy efficiency; 2. Forming an ecological chain between steel and related industries; 3. Pay attention to the use of scrap steel resources; 4. Improve the efficiency of steel use; 5. Reduce fossil fuel consumption and find alternatives to fossil fuels; 6. Carbon dioxide collection and storage. We will do a good job in energy conservation and emission reduction, innovate technology, reduce costs and increase efficiency, and coordinate upstream and downstream carbon reduction. Relying on iron ore to achieve the two-carbon goal can only be a transition from carbon reduction to hydrogen reduction. The breakthrough of hydrogen reduction technology may take a long time, so in the future, blast furnace ironmaking will still be the mainstream technology of iron and steel industry. In the traditional process of blast-coking-sintering iron making, dust and flue gas are discharged greatly. The pollutant emissions of sintering machine and coking plant account for more than half of the total emissions of iron and steel complex enterprises, and they are the biggest pollution sources in the steel production process. Due to the devastating effect of coking on the environment, Western countries have shut down 90% of coking equipment. Therefore, reducing coke ratio, increasing pellet ratio and reducing sinter ratio are the most effective ways to save energy and reduce emission in traditional iron and steel process. The transformation and upgrading of the steel industry and the road of low-carbon and green development are inevitable trends. The global production and marketing of direct reduced iron are flourishing, and the development of hydrogen metallurgy technology is a global consensus. Under the guidance of the two-carbon policy, the main domestic iron and steel enterprises have been involved in the field of non-blast furnace ironmaking technology. Make full use of the historic opportunities faced by the non-blast furnace smelting industry, meet the difficulties, and make the industry healthy and healthy development. In the context of the global development of low-carbon economy, China's non-blast furnace smelting industry has formed an innovative development trend of multi-process equipment and process routes. Under the policy guidance of carbon peak and carbon neutrality, the state encourages the development of non-blast furnace ironmaking technology, and iron and steel enterprises have the demand for transformation and development. The development of non-blast furnace iron-making technology is conducive to saving precious coking coal resources, conducive to the structural adjustment of the iron and steel industry, conducive to reducing environmental pollution and reducing CO2 emissions, conducive to the development of composite iron ore, refractory iron ore, conducive to the treatment of iron dust and ferrous slag in steel mills and other ferrous waste, in line with the general policy of circular economy. Non-blast furnace ironmaking technology is expected to become the trend of realizing low-carbon ironmaking in iron and steel industry.

Indications from the steel industry and local and global government institutions are that the breakthrough technologies for decarbonization will be based on hydrogen reduction. The employment of hydrogen in the ironmaking and steelmaking industries will push forward the global transformation of hard-to-abate industries.

First, amine-based post-combustion capture with a 95% capture rate was considered as the benchmark, as it is currently commercially available. A second, novel configuration integrated the Midrex process with pressurized chemical looping—direct reduced iron (PCL-DRI) production. The amine capture configuration is most sensitive to the cost of steam generation, while PCL-DRI is more sensitive to the cost of electricity and the makeup oxygen carrier. An iron-based natural ore is recommended for PCL-DRI due to the low cost and availability. Based on the lower costs compared to amine-based post-combustion capture, PCL-DRI is an attractive means of eliminating CO2 emissions from DRI production.

The replacement of the blast furnace—basic oxygen furnace (BF-BOF) steelmaking route with the direct reduced iron—electric arc furnace (DRI-EAF) route reduces the direct CO2 emissions from steelmaking by up to 68%; however, the DRI shaft furnace is one of the largest remaining point source emitters in steelmaking. The capital and operating expenses of two potential nearly carbon-neutral DRI process configurations were investigated as a modification to a standard Midrex DRI facility.

To overcome the limitations of the above two processes, and to achieve a more efficient direct reduction process of iron ore, the possibility of combining these two methods was investigated. The experiments focused on performing an initial direct reduction using ore-coal composite pellets followed by a second stage gas reduction. It was assumed that the initial reduction of the carbon composite pellets would enhance the efficiency of the subsequent reduction by gas and the total reduction efficiency. The porosity, as well as the carbon efficiency for direct reduction, were measured to determine the optimal conditions for the initial reduction, such as the size ratio of ore and coal particles. Thereafter, further reduction by the reducing gas was carried out to verify the effect of the preliminary reduction. The reduction kinetics of the reducing gas was also discussed.

Recently, direct reduced iron (DRI) has been highlighted as a promising iron source for electric arc furnace (EAF)-based steelmaking. The two typical production methods for DRI are gas-based reduction and reduction using carbon composite pellets. While the gas-based reduction is strongly dependent on the reliable supply of hydrocarbon fuel, reduction using ore-coal composite pellets has relatively low productivity due to solid–solid reactions.

Direct reduced iron has a relatively stable composition, low content of harmful impurities and relatively uniform particle size. As a high-quality raw material in modern metallurgy, direct reduced iron plays a vital role in metallurgy. In recent years, the application of direct reduced iron in the smelting of high-quality steel in electric furnaces, blast furnaces and other smelting furnaces is relatively common, which can effectively improve the production efficiency and reduce the coke ratio, and has positive significance for improving the overall efficiency of modern metallurgy. In addition, direct reduced iron can also be used in LD converter coolant and flat furnace effective metal raw materials, can also play a positive role.

Directly reduced iron added to the electric arc furnace proportion varies, if the proportion of direct reduction of iron is less than 30%, can be used cans of material loading. The bottom of the basket is filled with light scrap, followed by heavy scrap and direct-reduced iron, to avoid too much lumping of direct-reduced iron. However, when the arc heats the thicker layers of direct reduced iron, the molten metal fills the spaces between the direct reduced iron and condenses, causing the charge to sinter into a single piece, making it difficult to add the charge as a whole to the molten pool and extending the melting cycle. When more than 30% of the charge is added in batches, due to the slow heat transfer of the direct-reduced iron, the relevant technical indicators are poor, and should be fed into the furnace by means of continuous charging.

Under the background of the rapid development of the world's iron and steel technology, the pace of innovative technology methods is also accelerating, as a kind of efficient blast furnace steelmaking technology, direct reduction iron technology effectively improves the quality of iron and steel products. The article proposes four direct reduction iron production technologies.

Based on the conditions in these aggregates, a test series to experimentally simulate the first few seconds after charging DRI was defined. DRI samples with different carbon contents and hot briquetted iron (HBI) were immersed in high- and low-carbon melts as well as high- and low-iron oxide slags. The reacted samples were quenched in liquid nitrogen. The specimens were qualitatively evaluated by investigating their surfaces and cross sections.