Synergistic Use of CO₂ Pretreatment and Accelerated Carbonation Curing for Maximum Recycling of Steel Slag

Abstract

Two carbonation approaches are considered for studying the effects on the hardening mechanisms of slurries made of 100 wt% electric arc furnace steel slag (EAF) slag or 80 wt% EAF slag incorporating 20 wt% of Portland cement, which are applied during the hot-stage pretreatment with simulated gas for raw steel slag or the accelerated carbonation curing of slurry. The mechanical strengths, carbonate products, microstructures and CO₂ uptakes were quantitatively investigated. Results manifest that accelerated carbonation curing increases the compressive strengths of steel slag slurry, from 17.1 MPa (binder of 80 wt% EAF and 20 wt% cement under standard moisture curing) to 36.0 MPa (binder of 80 wt% EAF and 20 wt% cement under accelerated carbonation curing), with a CO₂ uptake of 52%. In contrast, hot-stage carbonation applied during the pretreatment of steel slag increases the compressive strengths to 43.7 MPa (binder of 80 wt% carbonated EAF and 20 wt% cement under accelerated carbonation curing), with a CO₂ uptake of 67%. Hotstage carbonation of steel slag is found for particle agglomeration, minerals remodeling and calcite formed, thus causing an activated steel slag with a dense structure and more active components. Accelerated carbonation curing of steel slag slurry paste results in the newly formed amorphous CaCO₃, calcite crystalline and silica gels that covered the pores of the matrix, facilitating microstructure densification and strength improvement. Adopting the combinative methods of the hot-stage CO₂ pretreatment and accelerated carbonation curing creates a promising high-volume steel slag-based binder with high strengths and CO₂ storage.

Keywords

high-volume steel slag binders / hot-stage CO₂ pretreatment / accelerated carbonation curing / CO₂ storage

References

[1] Eloneva S, Puheloinen E M, Kanerva J, et al. Co-Utilisation of CO₂ and Steelmaking Slags for Production of Pure CaCO₃-Legislative Issues[J]. J. Clean Prod., 2010, 18: 1833-1839.

[2] Guo J L, Bao Y P, Wang M. Steel Slag in China: Treatment, Recycling, and Management[J]. Waste Manage., 2018, 78: 318-330.

[3] Pan S Y, Adhikari R, Chen Y H, et al. Integrated and Innovative Steel Slag Utilization for Iron Reclamation, Green Material Production and CO₂ Fixation via Accelerated Carbonation[J]. J. Clean Prod., 2016, 137: 617-631.

[4] Carvalho S Z, Vernilli F, Almeida B, et al. The Recycling Effect of BOF Slag in the Portland Cement Properties[J]. Resour. Conserv. Recycl., 2017, 127: 216-220.

[5] Pasetto M, Baldo N. Recycling of Waste Aggregate in Cement Bound Mixtures for Road Pavement Bases and Sub-bases[J]. Constr. Build. Mater., 2016, 108: 112-118.

[6] Skaf M, Manso J M, Aragón Á, et al. EAF Slag in Asphalt Mixes: a Brief Review of Its Possible Re-Use[J]. Resour Conserv. Recycl., 2017, 120: 176-185.

[7] Poh H Y, Ghataora G S, Ghazireh N. Soil Stabilization Using Basic Oxygen Steel Slag Fines[J]. J. Mater Civil Eng., 2006, 18: 229-240.

[8] Huang Y, Xu G P, Cheng H G, et al. An Overview of Utilization of Steel Slag[J]. Procedia Environ. Sci., 2012, 16: 791-801.

[9] Mo L W, Zhang F, Deng M, et al. Accelerated Carbonation and Performance of Concrete Made with Steel Slag as Binding Materials and Aggregates[J]. Cem. Concr. Compos., 2017, 83: 138-145.

[10] Wang G, Wang Y H, Gao Z L. Use of Steel Slag as a Granular Material: Volume Expansion Prediction and Usability Criteria[J]. J. Hazard. Mater., 2010, 184: 555-560.

[11] Kim E, Spooren J, Broos K, et al. Valorization of Stainless Steel Slag by Selective Chromium Recovery and Subsequent Carbonation of the Matrix Material[J]. J. Clean Prod., 2016, 117: 221-228.

[12] Baciocchi R, Costa G, Gianfilippo M D, et al. Thin-Film versus Slurry-Phase Carbonation of Steel Slag: CO₂ Uptake and Effects on Mineralogy[J]. J. Hazard. Mater., 2015, 283: 302-313.

[13] Polettini A, Pomi R. The Leaching Behavior of Incinerator Bottom Ash as Affected by Accelerated Ageing[J]. J. Hazard. Mater., 2004, 113: 209-215.

[14] Pan S Y, Chung T C, Ho C C, et al. CO2 Mineralization and Utilization using Steel Slag for Establishing a Waste-to-Resource Supply Chain[J]. Sci. Rep., 2017, 7: 17227.

[15] Chang J, Fang Y F. Quantitative Analysis of Accelerated Carbonation Products of the Synthetic Calcium Silicate Hydrate(C-S-H) by QXRD and TG/MS[J]. J. Therm. Analy. Calori., 2015, 119: 57-62.

[16] Yu J, Wang K B. Study on Characteristics of Steel Slag for CO₂ Capture[J]. Energy Fuels, 2011, 25: 5483-5492.

[17] Wang X, Ni W, Li J J, et al. Carbonation of Steel Slag and Gypsum for Building Materials and Associated Reaction Mechanisms[J]. Cem. Concr. Res., 2019, 125: 105 893.

[18] Chang J, Cang X, Zhang Y Y, et al. Foaming Characteristics and Microstructure of Aerated Steel Slag Block Prepared by Accelerated Carbonation[J]. Constr. Build. Mater., 2019, 209: 222-233.

[19] Vagenas N V, Gatsouli A, Kontoyannis C G. Quantitative Analysis of Synthetic Calcium Carbonate Polymorphs Using FT-IR Spectroscopy[J]. Talan., 2003, 59: 831-836.

[20] Chang J, Fang Y F, Shang X P. The Role of β-C₂S and γ-C₂S in Carbon Capture and Strength Development[J]. Mater. Struct., 2016, 49: 4417-424.

[21] Ukwattage N L, Ranjith P G, Yellishetty M, et al. A Laboratory-Scale Study of the Aqueous Mineral Carbonation of Coal Fly Ash for CO₂ Sequestration[J]. J. Clean Prod., 2015, 103: 665-674.

[22] Moon E J, Choi Y C. Carbon Dioxide Fixation via Accelerated Carbonation of Cement-Based Materials: Potential for Construction Materials Applications[J]. Constr. Build. Mater., 2018, 199: 676-687.

[23] Lukas W. Substitution of Si in the Lattice of Ettringite[J]. Cem. Concr. Res., 1976, 6: 225.

[24] Jiang Y, Ling T C. Production of Artificial Aggregates from Steel-Making Slag: Influences of Accelerated Carbonation during Granulation and/or Post-Curing[J]. J. CO. Util., 2020, 36: 135-144.

[25] Guan X M, Liu S H, Feng C H, et al. The Hardening Behavior of γ-C₂S Binder Using Accelerated Carbonation[J]. Constr. Build. Mater., 2016, 114: 204-207.

[26] Muller A C A, Scrivener K L. A Reassessment of Mercury Intrusion Porosimetry by Comparison with ¹H NMR Relaxometry[J]. Cem. Concr. Res., 2017, 100: 350-360.

[27] Pizzol V D, Mendes L M, Frezzatti L, et al. Effect of Accelerated Carbonation on the Microstructure and Physical Properties of Hybrid Fiber-Cement Composites[J]. Miner. Eng., 2014, 59: 101-106.

[28] Thiery M, Villain G, Dangla P, et al. Investigation of the Carbonation Front Shape on Cementitious Materials: Effects of the Chemical Kinetics[J]. Cem. Concr. Res., 2007, 37: 1047-1058.

[29] Wang L, Chen L, Tsang D C W, et al. Green Remediation of Contaminated Sediment by Stabilization/Solidification with Industrial By-products and CO₂ Utilization[J]. Sci. Total Environ., 2018, 631: 1321-1327.

[30] Jeong Y N, Woo S Y, Juhyuk M, et al. Utilization of Precipitated CaCO₃ from Carbon Sequestration of Industrially Emitted CO₂ in Cementless CaO-Activated Blast-Furnace Slag Binder System[J]. J. Clean Prod., 2017, 166: 649-659.

[31] Black L, Stumm A, Garbev K, et al. X-ray Photoelectron Spectroscopy of the Cement Clinker Phases Tricalcium Silicate and β-Dicalcium Silicate[J]. Cem. Concr. Res., 2003, 33: 1561-1565.

[32] Black L, Breen C, Yarwood J, et al. Structural Features of C-S-H(I) and Its Carbonation in Air-a Raman Spectroscopic Study. Part II: Carbonated Phases[J]. J. Am. Ceram. Soc., 2007, 90: 908-917.

[33] Richardson I G. The Nature of C-S-H in Hardened Cements[J]. Cem. Concr. Res., 1999, 29: 1131-1147.

[34] Black L, Garbev K, Semmermann P, et al. Characterisation of Crystalline C-S-H Phases by X-ray Photoelectron Spectroscopy[J]. Cem. Concr. Res., 2003, 33: 899-911.

[35] Black L, Garbev K, Beuchle G, et al. X-ray Photoelectron Spectroscopic Investigation of Nanocrystalline Calcium Silicate Hydrates Synthesized by Reactive Milling[J]. Cem. Concr. Res., 2006, 36: 1023-1031.

[36] Okada K, Kameshima Y, Yasumori A. Chemical Shifts of Silicon X-ray Photoelectron Spectra by Polymerization Structures of Silicates[J]. J. Am. Ceram. Soc., 1998, 81: 1970-1972.

[37] Black L, Garbev K, Stemmermann P, et al. X-ray Photoelectron Study of Oxygen Bonding in Crystalline C-S-H Phases[J]. Phys. Chem. Miner., 2004, 31: 337-346.

[38] Ukwattage N L, Ranjith P G, Li X. Steel-Making Slag for Mineral Sequestration of Carbon Dioxide by Accelerated Carbonation[J]. Measurement, 2017, 97: 15-22.