New Efficient Process Utilizing Ludwigite on Gas-based Shaft Furnace Direct Reduction and Electric Furnace Smelting Separation

doi:10.12068/j.issn.1005-3026.2016.06.010

Abstract

Abstract: In this work， oxide pellet was prepared from boron-bearing iron concentrate. A new process that the boron-bearing iron concentrate was directly reduced and separated by shaft furnace and electric furnace smelting， respectively. The corresponding reduction and separation theories were discussed. The results showed that boron-bearing iron concentrate pelletization can fully meet the requirements of the gas-based shaft furnace direct reduction process. After boasting at 1200℃ for 20minutes， the compressive strength of the finished pellet is higher than 2500N. When the H₂ to CO ratio is higher than 2/5 and the temperature is between 850℃ to 1000℃， the time for reducing 95% of the boron-bearing iron concentrate is between 10min to 60min and the expansion ratio is less than 15%. Boron and iron can be efficiently separated from DRI by electric furnace at 1500℃. The yields of both boron and iron can achieve up to 98%. The activity and the mass fraction of B₂O₃ in the slag can reach 89% and 21%， respectively， suggesting that this kind of slag can be used as high quality raw materials for the one-step boric acid production. The new process can efficiently separate and cleanly utilize boron-bearing iron concentrate.

Key words: boron-bearing iron concentrate, gas-based shaft furnace, direct reduction, electric furnace smelting separation, clean utilization

CLC Number:

TF046.6

CHU Man-sheng， ZHAO Jia-qi， FU Xiao-jiao， LIU Zheng-gen. New Efficient Process Utilizing Ludwigite on Gas-based Shaft Furnace Direct Reduction and Electric Furnace Smelting Separation[J]. Journal of Northeastern University Natural Science, 2016, 37(6): 805-809.

References

[1]赵庆杰，王常任．硼铁矿的开发利用［J］．辽宁化工，2001，30(7):297-299.(Zhao Qing-jie，Wang Chang-ren.Development and application of paigeite ［J］.Liaoning Chemical Industry，2001，30(7):297-299.)
[2]Liu S L，Cui C M，Zhang X P.Pyrometallurgical separation of boron from iron in ludwigite ore［J］.ISIJ International，1998，38(10):1077-1079.
[3]Wang G，Wang J S，Ding Y G，et al.New separation method of boron and iron from ludwigite based on carbon bearing pellet reduction and melting technology［J］.ISIJ International，2012，52(1):45-51.
[4]付小佼，于洪翔，柳政根，等．含硼铁精矿选择性还原-选分新工艺的实验研究［J］．东北大学学报(自然科学版)，2013，34(7):966-970.(Fu Xiao-jiao，Yu Hong-xiang，Liu Zheng-gen，et al.Experimental study on new process for selective reduction and separation of boron-bearing iron concentrate［J］.Journal of Northeastern University(Natural Science)，2013，34(7):966-970.)
[5]Wang G，Ding Y G，Wang J S，et al.Effect of carbon species on the boron-bearing iron concentrate/carbon composite pellet reduction and melting behavior［J］.International Journal of Minerals，Metallurgy and Materials，2013，20(6):522-528.
[6]Midrex Technologies Inc.2013 World direct reduction statistics［R］.Charlotte:Midrex Inc，2014:1-14.
[7]Hu J G.Development of gas-based shaft furnace direct reduction technology［C］// Proceedings of the 5th International Congress on the Science and Technology of Ironmaking.Shanghai:The Chinese Society for Metals，2009:1293-1296.
[8]El-Geassy A A，Nasr M I，Hessien M M.Effect of reducing gas on the volume change during reduction of iron oxide compacts［J］.ISIJ International，1996，36(6):640-649.
[9]Usui T，Kawabata H，Ono H，et al.Fundamental experiments on the H₂ gas injection into the lower part of a blast furnace shaft［J］.Current Advances in Materials and Processes，2001，14(4):846-849.(上接第804页)
[4]Mio H，Komatsuki S，Akashi M，et al.Analysis of traveling behavior of nut coke particles in bell-type charging process of blast furnace by using discrete element method［J］.ISIJ International，2010，50(7):1000-1009.
[5]Zhou Z Y，Zhu H P，Wright B，et al.Gas-solid flow in an ironmaking blast furnace-II:discrete particle simulation［J］.Powder Technology，2011，208(1):72-85.
[6]车玉满，李连成，孙波，等.鞍钢无料钟布料数学模型研制与应用［J］.鞍钢技术，2008(5):16-22.(Che Yu-man，Li Lian-cheng，Sun Bo，et al.Development and application of burden distribution mathematical model of bell-less blast furnace in Angang［J］.Angang Technology，2008 (5):16-22.)
[7]Cundall P A，Strack O D L.A discrete numerical model for granular assemblies［J］.Geotechnique，1979，29(1):47-65.
[8]陈立胜，罗志国，游洋，等.挡板角度对挡板布料器布料过程的影响［J］.东北大学学报(自然科学版)，2013，34(7):971-974.(Chen Li-sheng，Luo Zhi-guo，You Yang，et al.Effect of flap angle on process of flap distributor charging［J］.Journal of Northeastern University(Natural Science)，2013，34(7):971-974.)
[9]Zhu H P，Zhou Z Y，Yang R Y，et al.Discrete particle simulation of particulate systems:theoretical developments［J］.Chemical Engineering Science，2007，62:3378-3396.
[10]李海峰，罗志国，张树才，等.溜槽角度对混装布料过程的影响［J］.东北大学学报(自然科学版)，2012，33(5):681-684.(Li Hai-feng，Luo Zhi-guo，Zhang Shu-cai，et al.Effect of chute angle on process of mixing charging［J］.Journal of Northeastern University(Natural Science)，2012，33(5):681-684.)
[11]Kou M Y，Wu S L，Du K P，et al.DEM simulation of burden distribution in the upper part of COREX shaft furnace［J］.ISIJ International，2013，53(6):1002-1009.