Hydrogen metallurgy is a technology that applies hydrogen instead of carbon as a reduction agent to reduce CO2 emission,and the use of hydrogen is beneficial to promoting the sustainable development of the steel indus...Hydrogen metallurgy is a technology that applies hydrogen instead of carbon as a reduction agent to reduce CO2 emission,and the use of hydrogen is beneficial to promoting the sustainable development of the steel industry.Hydrogen metallurgy has numerous applications,such as H2reduction ironmaking in Japan,ULCORED and hydrogen-based steelmaking in Europe;hydrogen flash ironmaking technology in the US;HYBRIT in the Nordics;Midrex H2TM by Midrex Technologies,Inc.(United States);H2FUTURE by Voestalpine(Austria);and SALCOS by Salzgitter AG(Germany).Hydrogen-rich blast furnaces(BFs)with COG injection are common in China.Running BFs have been industrially tested by AnSteel,XuSteel,and BenSteel.In a currently under construction pilot plant of a coal gasification–gas-based shaft furnace with an annual output of 10000 t direct reduction iron(DRI),a reducing gas composed of 57 vol%H2 and 38 vol%CO is prepared via the Ende method.The life cycle of the coal gasification–gas-based shaft furnace–electric furnace short process(30 wt%DRI+70 wt%scrap)is assessed with 1 t of molten steel as a functional unit.This plant has a total energy consumption per ton of steel of 263.67 kg standard coal and a CO2 emission per ton of steel of 829.89 kg,which are superior to those of a traditional BF converter process.Considering domestic materials and fuels,hydrogen production and storage,and hydrogen reduction characteristics,we believe that a hydrogen-rich shaft furnace will be suitable in China.Hydrogen production and storage with an economic and large-scale industrialization will promote the further development of a full hydrogen shaft furnace.展开更多
After taking into account the conditions of the domestic iron resources and the non-coking coal resources, the process of coal gasification-shaft furnace is an effective way to develop direct reduction iron in China. ...After taking into account the conditions of the domestic iron resources and the non-coking coal resources, the process of coal gasification-shaft furnace is an effective way to develop direct reduction iron in China. The following tasks are very critical to choose suitable process of shaft furnace and gasification, including the production of oxidized pellets with excellent comprehensive properties as well as the study of the reaction behavior and mechanism of swelling. The results showed that the oxidized pellets of using domestic magnetic iron concentrate as raw materials have favorable comprehensive properties, including higher mechanical strength both before and after reduction, faster reduction rate and lower reduction swelling index (RSI). All of these properties can meet the shaft furnace yielding requirement. When the temperature was below 1 223 K, the pellets′ RSI was lower than 20%. With increasing of the content of H2 in atmosphere, the pellets reaction rate accelerated, crushing strength enhanced and RSI decreased. The RSI dropped to 10.26% at 1 323 K in 100% H2 atmosphere, and it is up to 39.88% in 100% CO atmosphere. The iron grains mainly presented in platelike when pellets were reduced by H2, however, in CO atmosphere the iron grains were precipitated in flocculent. The whisker shape of iron grains and heating effects of reduction reaction are the major factors leading to the poor pellets strength and increase of RSI. Appropriately controlling the temperature and increasing the ratio of H2 to CO in atmosphere are good for dropping the RSI.展开更多
Hydrogen-based shaft furnace process is gaining more and more attention due to its low carbon emission, and the reduction behavior of iron bearing burdens significantly affects its operation. In this work, the effects...Hydrogen-based shaft furnace process is gaining more and more attention due to its low carbon emission, and the reduction behavior of iron bearing burdens significantly affects its operation. In this work, the effects of reduction degree, temperature, and atmosphere on the swelling behavior of pellet has been studied thoroughly under typical hydrogen metallurgy conditions. The results show that the pellets swelled rapidly in the early reduction stage, then reached a maximum reduction swelling index (RSI) at approximately 40%reduction degree. The crystalline transformation of the iron oxides during the reduction process was the main reason of pellets swelling. The RSI increased significantly with increasing temperature in the range of 850-1050℃, the maximum RSI increased from 6.66%to 25.0%in the gas composition of 100%H_(2). With the temperature increased, the pellets suffered more thermal stress resulting in an increase of the volume. The maximum RSI decreased from 19.78%to 17.35%with the volume proportion of H_(2) in the atmosphere increased from 55%to 100%at the temperature of 950℃.The metallic iron tended to precipitate in a lamellar structure rather than whiskers. Consequently, the inside of the pellets became regular, so the RSI decreased. Overall, controlling a reasonable temperature and increasing the H_(2) proportion is an effective way to decrease the RSI of pellets.展开更多
基金the National Natural Science Foundation of China(No.51904063)the Fundamental Research Funds for the Central Universities(Nos.N2025023,N172503016,N172502005,and N172506011)+1 种基金the China Postdoctoral Science Foundation(No.2018M640259)the Xingliao Talent Plan(No.XLYC1902118)。
文摘Hydrogen metallurgy is a technology that applies hydrogen instead of carbon as a reduction agent to reduce CO2 emission,and the use of hydrogen is beneficial to promoting the sustainable development of the steel industry.Hydrogen metallurgy has numerous applications,such as H2reduction ironmaking in Japan,ULCORED and hydrogen-based steelmaking in Europe;hydrogen flash ironmaking technology in the US;HYBRIT in the Nordics;Midrex H2TM by Midrex Technologies,Inc.(United States);H2FUTURE by Voestalpine(Austria);and SALCOS by Salzgitter AG(Germany).Hydrogen-rich blast furnaces(BFs)with COG injection are common in China.Running BFs have been industrially tested by AnSteel,XuSteel,and BenSteel.In a currently under construction pilot plant of a coal gasification–gas-based shaft furnace with an annual output of 10000 t direct reduction iron(DRI),a reducing gas composed of 57 vol%H2 and 38 vol%CO is prepared via the Ende method.The life cycle of the coal gasification–gas-based shaft furnace–electric furnace short process(30 wt%DRI+70 wt%scrap)is assessed with 1 t of molten steel as a functional unit.This plant has a total energy consumption per ton of steel of 263.67 kg standard coal and a CO2 emission per ton of steel of 829.89 kg,which are superior to those of a traditional BF converter process.Considering domestic materials and fuels,hydrogen production and storage,and hydrogen reduction characteristics,we believe that a hydrogen-rich shaft furnace will be suitable in China.Hydrogen production and storage with an economic and large-scale industrialization will promote the further development of a full hydrogen shaft furnace.
基金Item Sponsored by National Natural Science Foundation of China (51090384)Fundamental Research Funds for Central Universities of China (N090602005,N110202001)
文摘After taking into account the conditions of the domestic iron resources and the non-coking coal resources, the process of coal gasification-shaft furnace is an effective way to develop direct reduction iron in China. The following tasks are very critical to choose suitable process of shaft furnace and gasification, including the production of oxidized pellets with excellent comprehensive properties as well as the study of the reaction behavior and mechanism of swelling. The results showed that the oxidized pellets of using domestic magnetic iron concentrate as raw materials have favorable comprehensive properties, including higher mechanical strength both before and after reduction, faster reduction rate and lower reduction swelling index (RSI). All of these properties can meet the shaft furnace yielding requirement. When the temperature was below 1 223 K, the pellets′ RSI was lower than 20%. With increasing of the content of H2 in atmosphere, the pellets reaction rate accelerated, crushing strength enhanced and RSI decreased. The RSI dropped to 10.26% at 1 323 K in 100% H2 atmosphere, and it is up to 39.88% in 100% CO atmosphere. The iron grains mainly presented in platelike when pellets were reduced by H2, however, in CO atmosphere the iron grains were precipitated in flocculent. The whisker shape of iron grains and heating effects of reduction reaction are the major factors leading to the poor pellets strength and increase of RSI. Appropriately controlling the temperature and increasing the ratio of H2 to CO in atmosphere are good for dropping the RSI.
基金financially supported by the National Natural Science Foundation of China (No.51904063)the China Postdoctoral Science Foundation (No.2018M640259)+2 种基金the Fundamental Research Funds for the Central Universities(No.N2025023)the Key research and development project of Hebei Province (No.21314001D)the Plan of Xingliao Talents,China (No.XLYC1902118)。
文摘Hydrogen-based shaft furnace process is gaining more and more attention due to its low carbon emission, and the reduction behavior of iron bearing burdens significantly affects its operation. In this work, the effects of reduction degree, temperature, and atmosphere on the swelling behavior of pellet has been studied thoroughly under typical hydrogen metallurgy conditions. The results show that the pellets swelled rapidly in the early reduction stage, then reached a maximum reduction swelling index (RSI) at approximately 40%reduction degree. The crystalline transformation of the iron oxides during the reduction process was the main reason of pellets swelling. The RSI increased significantly with increasing temperature in the range of 850-1050℃, the maximum RSI increased from 6.66%to 25.0%in the gas composition of 100%H_(2). With the temperature increased, the pellets suffered more thermal stress resulting in an increase of the volume. The maximum RSI decreased from 19.78%to 17.35%with the volume proportion of H_(2) in the atmosphere increased from 55%to 100%at the temperature of 950℃.The metallic iron tended to precipitate in a lamellar structure rather than whiskers. Consequently, the inside of the pellets became regular, so the RSI decreased. Overall, controlling a reasonable temperature and increasing the H_(2) proportion is an effective way to decrease the RSI of pellets.
