CO还原气氛下铁酸锌选择性分解过程研究
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摘要
为将电炉粉尘中铁酸锌选择性分解为Fe_3O_4和ZnO,采用热力学软件分析了铁酸锌在CO气氛下还原分解的热力学过程和分解特征,讨论了反应温度和气体组成对铁酸锌分解行为的影响。结果表明:铁酸锌的气体还原遵循逐级还原规律,很容易被CO还原为Fe_3O_4和ZnO,也易过还原为FeO和Fe,甚至可将ZnO还原为锌蒸气;控制P_(CO)/(P_(CO)+P_(CO_2))在0.05～0.20之间,温度在600～700℃范围内,可实现铁酸锌的高效分解、抑制铁氧化物的过还原;对CO还原气氛下铁酸锌分解过程进行了热力学模拟,计算出铁酸锌还原初期时的CO利用率约为35%。
In order to selectively decompose zinc ferrite in electric furnace dust into Fe_3O_4 and ZnO, the thermodynamic process and decomposition characteristics of zinc ferrite in CO reducing atmosphere were analyzed with a thermodynamic software, and effects of reaction temperature and gas compositions on the decomposition behavior of zinc ferrite were discussed. The results showed that the reduction of zinc ferrite followed a stepwise process. Zinc ferrite was prone to being reduced to Fe_3O_4 and ZnO, or over-reduced to FeO and Fe. And ZnO could even be reduced to zinc vapor. With P_(CO)/(P_(CO)+P_(CO_2)) controlled within 0.05～0.20 and temperature within the range of 600～700 ℃, zinc ferrite could be decomposed efficiently and the over-reduction of iron could be suppressed. Based on the thermodynamics simulation of the decomposition of zinc ferrite in CO reducing atmosphere, the CO utilization rate in the initial period of zinc ferrite reduction was calculated to be around 35%.
In order to selectively decompose zinc ferrite in electric furnace dust into Fe_3O_4 and ZnO, the thermodynamic process and decomposition characteristics of zinc ferrite in CO reducing atmosphere were analyzed with a thermodynamic software, and effects of reaction temperature and gas compositions on the decomposition behavior of zinc ferrite were discussed. The results showed that the reduction of zinc ferrite followed a stepwise process. Zinc ferrite was prone to being reduced to Fe_3O_4 and ZnO, or over-reduced to FeO and Fe. And ZnO could even be reduced to zinc vapor. With P_(CO)/(P_(CO)+P_(CO_2)) controlled within 0.05～0.20 and temperature within the range of 600～700 ℃, zinc ferrite could be decomposed efficiently and the over-reduction of iron could be suppressed. Based on the thermodynamics simulation of the decomposition of zinc ferrite in CO reducing atmosphere, the CO utilization rate in the initial period of zinc ferrite reduction was calculated to be around 35%.
引文
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[8]胡晓军,刘俊宝,郭培民,等.铁酸锌气体还原的热力学分析[J].工程科学学报,2015,37(4):429-435.
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[10]侯栋科,彭兵,柴立元,等.铁酸锌选择性还原的反应机理[J].中国有色金属学报,2014,24(10):2634-2641.
[11]彭宁,邱朝阳.南非钒钛磁铁矿流化床直接还原实验研究[J].矿冶工程,2018,39(2):95-98.
[2]Araújo J A D,Schalch V.Recycling of electric arc furnace(EAF)dust for use in steel making process[J].J Mater Res Technol,2014,3(3):274-279.
[3]Kuurugya F,Vindt T,Havlik T.Behavior of zinc,iron and calcium from electric arc furnace(EAF)dust in hydrometallurgical processing in sulfuric acid solutions:Thermodynamic and kinetic aspects[J].Hydrometallurgy,2015,154:20-32.
[4]Chairaksa-Fujimoto R,Maruyama K,Miki T,et al.The selective alkaline leaching of zinc oxide from Electric Are Furnace dust pretreated with calcium oxide[J].Hydrometallurgy,2016,159:120-125.
[5]Yu G,Peng N,Zhou L,et al.Selective reduction process of zinc ferrite and its application in treatment of zinc leaching residues[J].Trans Nonferrous Met Soc China,2015,25(8):2744-2752.
[6]Leclerc N,Meux E,Lecuire J M.Hydrometallurgical extraction of zinc from zinc ferrites[J].Hydrometallurgy,2003,70(1-3):175-183.
[7]韩俊伟,刘维,覃文庆,等.CO还原焙烧铁酸锌的选择性分解行为[J].中国有色金属学报,2016,26(6):1324-1331.
[8]胡晓军,刘俊宝,郭培民,等.铁酸锌气体还原的热力学分析[J].工程科学学报,2015,37(4):429-435.
[9]Bale C W,Chartrand P,Degterov S A,et al.Fact Sage Thermo-Chemical Software and Databases[J].Calphad,2002,26(2):189-228.
[10]侯栋科,彭兵,柴立元,等.铁酸锌选择性还原的反应机理[J].中国有色金属学报,2014,24(10):2634-2641.
[11]彭宁,邱朝阳.南非钒钛磁铁矿流化床直接还原实验研究[J].矿冶工程,2018,39(2):95-98.