Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF) steelmaking, electric-arc-furnace (EAF) steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L)] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD) analyses and Scanning Electron Microscopy (SEM) studies. The XRD patterns of both BOF and EAF(L) slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L) slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L) slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties. 1. Introduction The steelmaking industries in the US generate 10–15 million tons of steel slag every year. Approximately 15 to 40% of the steel slag output is initially stockpiled in the steel plants and, eventually, sent to slag disposal sites. Utilization of steel slag in civil engineering applications can alleviate the need for their disposal and reduce the use of natural resources. A better understanding of the properties of steel slag is required for large volumes of this material to be utilized in a technically sound manner in civil engineering applications. Knowledge of the chemical, mineralogical, and morphological properties of steel slags is essential because their cementitious and mechanical properties, which play a key role in their utilization, are closely linked to these properties. As an example, the frictional properties of steel slag are influenced by its morphology and mineralogy. Similarly, the volumetric stability of steel slag is a function of its chemistry and mineralogy. The chemical, mineralogical, and morphological characteristics of steel slag are determined by the processes that generate this material. Therefore, knowledge of the different types of steelmaking and refining operations that produce steel slag as a byproduct is also required. This paper provides an overview of steel slag generation and a literature review on the chemical
References
[1]
H. Schoenberger, “Final draft: best available techniques reference document on the production of iron and steel,” Publications of EC: European Commission, Joint Research Centre, IPTS, European IPPC Bureau, 2001.
[2]
Energy Manager Training (EMT), “Iron and steel process,” July 2008, http://www.energymanagertraining.com/.
[3]
D. Brandt and J. C. Warner, Metallurgy Fundamentals, Goodheart-Willcox, Tinley Park, Ill, USA, 3rd edition, 2005.
[4]
American Iron and Steel Institute (AISI), “How Steel is Made,” October 2011, http://www.steel.org/.
[5]
S. Seetharaman, Fundamentals of Metallurgy, Woodhead Publishing and CRC Press, Boca Raton, Fla, USA, 2005.
[6]
United Stated Geological Survey (USGS), “Slag-iron and steel,” Annual Review, Mineral Industry Surveys, U.S. Geological Survey, Minerals Yearbook, Reston, Va, USA, 1993–2006.
[7]
B. Das, S. Prakash, P. S. R. Reddy, and V. N. Misra, “An overview of utilization of slag and sludge from steel industries,” Resources, Conservation and Recycling, vol. 50, no. 1, pp. 40–57, 2007.
[8]
L. M. Juckes, “The volume stability of modern steelmaking slags,” Mineral Processing and Extractive Metallurgy, vol. 112, no. 3, pp. 177–197, 2003.
[9]
P. Y. Mahieux, J. E. Aubert, and G. Escadeillas, “Utilization of weathered basic oxygen furnace slag in the production of hydraulic road binders,” Construction and Building Materials, vol. 23, no. 2, pp. 742–747, 2009.
[10]
H. Y. Poh, G. S. Ghataora, and N. Ghazireh, “Soil stabilization using basic oxygen steel slag fines,” Journal of Materials in Civil Engineering, vol. 18, no. 2, pp. 229–240, 2006.
[11]
D. H. Shen, C. M. Wu, and J. C. Du, “Laboratory investigation of basic oxygen furnace slag for substitution of aggregate in porous asphalt mixture,” Construction and Building Materials, vol. 23, no. 1, pp. 453–461, 2009.
[12]
C. Shi, “Steel slag—its production, processing, characteristics, and cementitious properties,” Journal of Materials in Civil Engineering, vol. 16, no. 3, pp. 230–236, 2004.
[13]
M. Tossavainen, F. Engstrom, Q. Yang, N. Menad, M. L. Larsson, and B. Bjorkman, “Characteristics of steel slag under different cooling conditions,” Waste Management, vol. 27, no. 10, pp. 1335–1344, 2007.
[14]
J. Waligora, D. Bulteel, P. Degrugilliers, D. Damidot, J. L. Potdevin, and M. Measson, “Chemical and mineralogical characterizations of LD converter steel slags: a multi-analytical techniques approach,” Materials Characterization, vol. 61, no. 1, pp. 39–48, 2010.
[15]
W. Xuequan, Z. Hong, H. Xinkai, and L. Husen, “Study on steel slag and fly ash composite Portland cement,” Cement and Concrete Research, vol. 29, no. 7, pp. 1103–1106, 1999.
[16]
M. Barra, E. V. Ramonich, and M. A. Munoz, “Stabilization of soils with steel slag and cement for application in rural and low traffic roads,” in Proceedings of the Beneficial Use of Recycled Materials in Transportation Application, pp. 423–432, RMCR University of Durham, Arlington, Va, November 2001.
[17]
M. P. Luxán, R. Sotolongo, F. Dorrego, and E. Herrero, “Characteristics of the slags produced in the fusion of scrap steel by electric arc furnace,” Cement and Concrete Research, vol. 30, no. 4, pp. 517–519, 2000.
[18]
J. M. Manso, J. A. Polanco, M. Losa？ez, and J. J. González, “Durability of concrete made with EAF slag as aggregate,” Cement and Concrete Composites, vol. 28, no. 6, pp. 528–534, 2006.
[19]
P. E. Tsakiridis, G. D. Papadimitriou, S. Tsivilis, and C. Koroneos, “Utilization of steel slag for Portland cement clinker production,” Journal of Hazardous Materials, vol. 152, no. 2, pp. 805–811, 2008.
[20]
M. Nicolae, I. V？lciu, and F. Zǎman, “X-ray diffraction analysis of steel slag and blast furnace slag viewing their use for road construction,” UPB Scientific Bulletin Series B, vol. 69, no. 2, pp. 99–108, 2007.
[21]
G. R. Qian, D. D. Sun, J. H. Tay, and Z. Y. Lai, “Hydrothermal reaction and autoclave stability of Mg bearing RO phase in steel slag,” British Ceramic Transactions, vol. 101, no. 4, pp. 159–164, 2002.
[22]
J. Setién, D. Hernández, and J. J. González, “Characterization of ladle furnace basic slag for use as a construction material,” Construction and Building Materials, vol. 23, no. 5, pp. 1788–1794, 2009.
[23]
H. L. Robinson, “The utilization of blastfurnace and steel making slags as aggregates for construction,” in Proceedings of the 11th Extractive Industry Geology Conference, pp. 327–330, The Geological Society of London, 2000, 36th forum on the Geology of Industrial Minerals, Industrial Minerals and Extractive Industry Geology.
[24]
H. Shen, E. Forssberg, and U. Nordstr？m, “Physicochemical and mineralogical properties of stainless steel slags oriented to metal recovery,” Resources, Conservation and Recycling, vol. 40, no. 3, pp. 245–271, 2004.
[25]
J. Geiseler, “Use of steelworks slag in Europe,” Waste Management, vol. 16, no. 1–3, pp. 59–63, 1996.
[26]
J. M. Manso, M. Losa？ez, J. A. Polanco, and J. J. Gonzalez, “Ladle furnace slag in construction,” Journal of Materials in Civil Engineering, vol. 17, no. 5, pp. 513–518, 2005.
[27]
A. S. Reddy, R. K. Pradhan, and S. Chandra, “Utilization of Basic Oxygen Furnace (BOF) slag in the production of a hydraulic cement binder,” International Journal of Mineral Processing, vol. 79, no. 2, pp. 98–105, 2006.
[28]
F. Wachsmuth, J. Geiseler, W. Fix, K. Koch, and K. Schwerdtfeger, “Contribution to the structure of BOF-slags and its influence on their volume stability,” Canadian Metallurgical Quarterly, vol. 20, no. 3, pp. 279–284, 1981.
[29]
A. Monaco and W. K. Wu, “The effect of cooling conditions on the characterization of steel slag,” in Proceedings of the International Symposium on Resource Conservation and Environmental Technologies in Metallurgical Industry, pp. 107–116, Toronto, Canada, August 1994.
[30]
C. Shi, “Characteristics and cementitious properties of ladle slag fines from steel production,” Cement and Concrete Research, vol. 32, no. 3, pp. 459–462, 2002.
[31]
G. Qian, D. D. Sun, J. H. Tay, Z. Lai, and G. Xu, “Autoclave properties of kirschsteinite-based steel slag,” Cement and Concrete Research, vol. 32, no. 9, pp. 1377–1382, 2002.
[32]
V. S. Ramachandran, P. J. Sereda, and R. F. Feldman, “Mechanism of hydration of calcium oxide,” Nature, vol. 201, no. 4916, pp. 288–299, 1964.
[33]
A. W. Kneller, J. Gupta, L. M. Borkowski, and D. Dollimore, “Determination of original free lime content of weathered iron and steel slags by thermogravimetric analysis,” Transportation Research Record 1434, Transportation Research Board, National Research Council, Washington, DC, USA, 1994.
[34]
C. B. Crawford and K. N. Burn, “Building damage from expansive steel slag backfill,” Journal of the Soil Mechanics and Foundations Division, vol. 95, no. 6, pp. 1325–1334, 1969.
[35]
A. Verhasselt and F. Choquet, “Steel slags as unbound aggregate in road construction: problems and recommendations,” in Proceedings of the International Symposium on Unbound Aggregates in Roads, pp. 204–211, London, UK, 1989.
[36]
J. Geiseler, “Steel slag-generation, processing and utilization,” in Proceedings of the International Symposium on Resource Conservation and Environmental Technologies in Metallurgical Industry, pp. 87–97, Toronto, Canada, August 1994.
[37]
H. Motz and J. Geiseler, “Products of steel slags an opportunity to save natural resources,” Waste Management, vol. 21, no. 3, pp. 285–293, 2001.
[38]
I. A. Altun and I. Yilmaz, “Study on steel furnace slags with high MgO as additive in Portland cement,” Cement and Concrete Research, vol. 32, no. 8, pp. 1247–1249, 2002.
[39]
P. Chaurand, J. Rose, V. Briois et al., “Environmental impacts of steel slag reused in road construction: a crystallographic and molecular (XANES) approach,” Journal of Hazardous Materials, vol. 139, no. 3, pp. 537–542, 2007.
