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熔融还原过程中水淬残渣物相组成变化规律是钢渣熔融还原基础问题之一。研究了不同CaO掺量对煤矸石中残碳为碳源还原钢渣的还原率、回收率以及残渣的组成和微观结构变化。结果表明：体系碱度系数K为1.33时(外掺10%(质量分数)左右的CaO)，铁的还原率和回收率最高，均可达97%。随着K值增加，还原率和回收率均降低。1500℃熔融还原的残渣，随着K值增加残渣中的β-C2S和C3S等物相含量逐渐增加。在碱度系数大于1.6时体系中出现方镁石，且方镁石主要出现于C3S形成的区域。C3S的大量形成导致基体中Al2O3浓度相对增加，从而形成了C3A。
Abstract：Introduction The use of steel slag as a cementitious material is the most likely field to achieve large-scale engineering utilization.However,the inherent defects of low activity and poor grindability caused by the high iron oxide content of steel slag limit its dosage in cement.One important direction to improve the activity and grindability of steel slag is to obtain a product similar to granulated blast furnace slag (GBFS),mainly composed of glass,by melting and reducing iron oxides in steel slag.This GBFS-like residue exhibits lower early activity due to its lower alkalinity coefficient (K=n(Ca O)+n(Mg O)/n(Si O2)+n(Al2O3)).In order to improve the early activity of the residue,this paper focuses on the effect of CaO content on the formation of clinker minerals.Coal gangue is used as a reducing agent to reduce iron oxides in steel slag for making full use of industrial solid waste.Methods Based on the principle of complete reduction of iron oxides in steel slag and coal gangue,the appropriate ratio of coal gangue and steel slag is calculated according to the chemical composition of steel slag and the fixed carbon content of coal gangue.Ca O was obtained by calcining and analytical reagent CaCO3 at 1500℃.Different amounts of resultant CaO (10,20,30,40 g) were incorporated into 100 g mixture of steel slag and coal gangue,respectively.The reference sample without CaO and the above four samples are named as C0,C10,C20,C30 and C40,and the K of samples are 1.05,1.33,1.61,1.89,2.17,respectively.After thoroughly mixing each sample,200 g mixture containing CaO was placed into a corundum crucible and calcined at 1500℃ for 30min.After calcination,the crucible was take out from the high temperature furnace for water quenching.Iron alloy particles are obtained by crushing,peeling,and magnetic separation from water quenched slag.The remaining water quenched residue (WQR) is used for mineral phase analysis,cement mortar strength,soundness,and other tests.Results and discussion Iron alloy particles in C0,C10,C20,C30 sample can be easily peeled off.But it is difficult for C40 sample and some small metal particles can be observed at the crucible bottom.This is because the increase of K leads to an increase in the viscosity of the melt,making it difficult for iron particles to sedimentation and aggregation. The analysis of the chemical composition of the WQR after stripping iron particles shows that the reduction rate δ and recovery rate η of the reference sample C0 are about 92%.For C10 (K=1.33),the η and δ of Fe reach maximum values.As the Ca O content continues to increase,the η and δ gradually decrease.But,these two parameters of C20 still exceed that of C0.The f-Ca O content and soundness of the WQR meet the requirements of relevant national standards,although these two values will slightly increase with the increase of dosage of Ca O. The results of XRD Rietveld refinement for quantification indicate that C0 and C10 samples are mainly consist of glass and contain a small amounts of Gehlenite,spinel et al.With the increase of Ca O content,the diffraction peak of the crystalline phase gradually increases,while the amorphous envelope peak gradually weakens.For C20,the main crystalline phases are C2S and bredigite,and diffraction peaks of periclase can be observed.In the C30 sample,the main mineral phases are C2S,C3A,iron,and periclase.Meanwhile,C3S diffraction peak is relatively low.The C3S diffraction peak in the C40 sample is significantly enhanced,with a content of 50%.FTIR shows that as the Ca O content increases from 20 g to 40 g,the absorption band of β-C2S decreases,while the absorption band of M3 C3S gradually increases. BSE image show that the C10 sample is mainly composed of glass matrix,with a small amount of C2S grain,serrated-like fine stuff formed at the edge of C2S grains,snowflake like or dendritic substance surrounding the C2S,and iron particles.EDS results show that the order of Al content in several phases is C2S
[1]王强,黎梦圆,石梦晓.水泥-钢渣-矿渣复合胶凝材料的水化特性[J].硅酸盐学报, 2014, 42(5):629–634.WANG Qiang, LI Mengyuan, SHI Mengxiao. J Chin Ceram Soc, 2014,42(5):629–634.
[2]赵德强,沈卫国,王桂明,等.不同种类转炉钢渣对高铁分相熟料烧成与性能的影响[J].硅酸盐学报, 2023, 51(8):1885–1897.ZHAO Deqiang, SHEN Weiguo, WANG Guimin, et al. J Chin Ceram Soc, 2023, 51(08):1885–1897.
[3]殷素红,郭辉,余其俊,等.还原铁法重构钢渣及其矿物组成[J].硅酸盐学报, 2013, 41(7):966–971.YIN Suhong, GUO Hui, YU Qijun, et al. J Chin Ceram Soc, 2013,41(7):966–971.
[4] LEE J, AN S B, SHIN M, et al. Valorization of electrical arc furnace oxidizing slag[C]//Celebrating the Megascale:Proceedings of the Extraction and Processing Division Symposium on Pyrometallurgy in Honor of David GC Robertson, 2016:347–355.
[5] GUO H, YIN S H, YU Q J, et al. Iron recovery and active residue production from basic oxygen furnace(BOF)slag for supplementary cementitious materials[J]. Resour Conserv Recycl, 2018, 129:209–218.
[6] LIU C W, HUANG S G, WOLLANTS P, et al. Valorization of BOF steel slag by reduction and phase modification:Metal recovery and slag valorization[J]. Metall Mater Trans B, 2017, 48(3):1602–1612.
[7] LINDVALL M, YE G. Experiences of using various metallurgical reactors for reduction of vanadium bearing steel slags and other wastes[C]//International Smelting Technology Symposium:Incorporating the6th Advances in Sulfide Smelting Symposium, 2012:147-154.
[8] LYU B B, WANG G, ZHAO L D, et al. Effect of atmosphere and basicity on softening–melting behavior of primary slag formation in cohesive zone[J]. J Iron Steel Res Int, 2023, 30(2):227–235.
[9] MORITA K, GUO M X, OKA N, et al. Resurrection of the iron and phosphorus resource in steel-making slag[J]. J Mater Cycles Waste Manag, 2002, 4(2):93–101.
[10]郭辉.转炉钢渣中铁的还原回收及制备高胶凝性水淬渣的方法研究[D].广州:华南理工大学, 2018.GUO Hui. Study on reduction and recovery of iron from converter steel slag and preparation of high gelling water-quenched slag[D].Guangzhou:South China University of Technology, 2018.
[11]杨曜.钢渣中FeOx还原反应热力学、Fe还原回收效果及余渣性能的研究[D].广州:华南理工大学, 2013.YANG Yao. Study on thermodynamics of FeOx reduction reaction in steel slag, recovery effect of Fe reduction and properties of residual slag[D].Guangzhou:South China University of Technology, 2013.
[12] MIN D J, HAN J W, CHUNG W S. A study of the reduction rate of FeO in slag by solid carbon[J]. Metall Mater Trans B, 1999, 30(2):215–221.
[13] PARAMGURU R K, GALGALI R K, RAY H S. Influence of slag and foam characteristics on reduction of FeO-containing slags by solid carbon[J]. Metall Mater Trans B, 1997, 28(5):805–810.
[14] SARMA B, CRAMB A W, FRUEHAN R J. Reduction of FeO in smelting slags by solid carbon:Experimental results[J]. Metall Mater Trans B, 1996, 27(5):717–730.
[15]宋强,聂娇,宋甜甜,等.温度对煤矸石还原钢渣铁氧化物制备的水淬渣活性的影响[J].硅酸盐学报, 2024, 52(2):522–532.SONG Qiang, NIE Jiao, SONG Tiantian, et al. J Chin Ceram Soc, 2024,52(2):522–532.
[16] LI Z B, ZHAO S Y, ZHAO X G, et al. Cementitious property modification of basic oxygen furnace steel slag[J]. Constr Build Mater,2013, 48:575–579.
[17] LE SAO?T G, KOCABA V, SCRIVENER K. Application of the Rietveld method to the analysis of anhydrous cement[J]. Cem Concr Res, 2011, 41(2):133–148.
[18] CHEN Z M, LI R, ZHENG X M, et al. Carbon sequestration of steel slag and carbonation for activating RO phase[J]. Cem Concr Res, 2021,139:106271.
[19]王彬,任雪红,张文生.以不同磷酸钙盐形式引入P5+掺杂对阿利特结构及活性的影响[J].硅酸盐学报, 2013, 41(5):644–649.WANG Bin, REN Xuehong, ZHANG Wensheng. J Chin Ceram Soc,2013, 41(5):644–649.
[20]任雪红,张文生,叶家元,等.氧化铁掺杂对阿利特结构及活性的影响[J].硅酸盐学报, 2015, 43(8):1120–1128.REN Xuehong, ZHANG Wensheng, YE Jiayuan, et al. J Chin Ceram Soc, 2015, 43(8):1120–1128.
[21] SITARZ M. The structure of simple silicate glasses in the light of Middle Infrared spectroscopy studies[J]. J Non Cryst Solids, 2011,357(6):1603–1608.
[22] MOLLAH M Y A, YU W H, SCHENNACH R, et al. A Fourier transform infrared spectroscopic investigation of the early hydration of Portland cement and the influence of sodium lignosulfonate[J]. Cem Concr Res, 2000, 30(2):267–273.
[23] YLMéN R, J?GLID U, STEENARI B M, et al. Early hydration and setting of Portland cement monitored by IR, SEM and Vicat techniques[J]. Cem Concr Res, 2009, 39(5):433–439.
[24] MA H Y, TIAN Y, LI Z J. Interactions between organic and inorganic phases in PA-and PU/PA-modified-cement-based materials[J]. J Mater Civ Eng, 2011, 23(10):1412–1421.
[25] ROMANO J S, RODRIGUES F A. Titanium-bearing dicalcium silicates from rice hull ash:Synthesis and properties[J]. J Am Ceram Soc, 2007, 90(7):2259–2261.
[26] MOUDAR J, AGOURRAME H, EL FAMI N, et al. Stabilization and characterization of dicalcium silicate belite phase by metallic zinc[J].Mater Today Proc, 2022, 58:1442–1446.
[27] TIMóN V, TORRENS-MARTIN D, FERNáNDEZ-CARRASCO L J,et al. Infrared and Raman vibrational modelling of β-C2S and C3S compounds[J]. Cem Concr Res, 2023, 169:107162.
[28] XIE L, LUO D P, ZHU Y G, et al. Luminescence and mineralization properties of Gd3+stabilized β-dicalcium silicate[J]. Phys B Condens Matter, 2021, 610:412625.
[29] REN X H, ZHANG W S, YE J Y. FTIR study on the polymorphic structure of tricalcium silicate[J]. Cem Concr Res, 2017, 99:129–136.
[30] ZHOU H, XING Y J, ZHOU M X. Effects of modified Kaolin adsorbents on sodium adsorption efficiency and ash fusion characteristics during Zhundong coal combustion[J]. J Energy Inst, 2021, 97:203–212.
[31] RAJKOHILA A, PRAKASH CHANDAR S, RAVICHANDRAN P T.Assessing the effect of natural fiber on mechanical properties and microstructural characteristics of high strength concrete[J]. Ain Shams Eng J, 2024, 15(5):102666.
[32] CHARGUI F, HAMIDOUCHE M, BELHOUCHET H, et al. Mullite fabrication from natural Kaolin and aluminium slag[J]. Boletín De La Soc Espa?ola De Cerámica Y Vidrio, 2018, 57(4):169–177.
[33] AMAR M, LADDURI B, ALLOUL A, et al. Microstructure and mechanical properties of geopolymers utilizing excavated soils,metakaolin and slags[J]. J Build Eng, 2024, 86:108755.
[34] WANG Y W, LIU S F, HUANG P F, et al. Structural and magnetic properties of mono-dispersed iron carbide(FexCy)nanoparticles synthesized by facile gas phase reaction[J]. Ceram Int, 2019, 45(8):11119–11124.
[35] KANTRO D L, WEISE C H. Hydration of various beta-dicalcium silicate preparations[J]. J Am Ceram Soc, 1979, 62(11/12):621–626.
[36] FUJII K, KONDO W. Rate and mechanism of hydration of β-dicalcium silicate[J]. J Am Ceram Soc, 1979, 62(3/4):161–167.
[37] ZHANG W S, ZHANG J T, YE J Y, et al. Hydration kinetics and microstructure development of normal and NaAlO2-activated Al-dopedβ-C2S pastes[J]. J Am Ceram Soc, 2022, 105(3):2221–2233.
基本信息:
DOI：10.14062/j.issn.0454-5648.20240574
中图分类号:TQ172.1
引用信息:
[1]宋强,宋甜甜,聂娇等.氧化钙掺量对钢渣熔融还原水淬残渣中熟料矿物形成的影响[J].硅酸盐学报,2025,53(05):1121-1132.DOI:10.14062/j.issn.0454-5648.20240574.
基金信息:
陕西省科学技术研究计划(2024GX-YBXM-401,2024GXYBXM-370); 陕西省教育厅重点研发计划(20JY040)