Activity of reducing steel slag of EAF

Abstract

Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF) steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C₂S, C₃S, C₂F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO₃ content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

Keywords

strength activity index / basicity / EAF steelmaking / reducing steel slag

References

[1] Manso J. M., Polanco J. A., Losanez M. Durability of Concrete Made with EAF Slag as Aggregate[J]. Cement and Concrete Composites, 2006, 28(6): 528-534.

[2] Frías M., Rodríguez C. Effect of Incorporating Ferroalloy Industry Wastes as Complementary Cementing Materials on the Properties of Blended Cement Matrices[J]. Cement and Concrete Composites, 2008, 30(3): 212-219.

[3] Rojas M. F., Sanchez de Rojas M. I. Chemical Assessment of the Electric Arc Furnace Slag as Construction Material: Expansive Compounds [J]. Cement and Concrete Research, 2004, 34(10): 1 881-1 888.

[4] Tsubone A. Direct Recycling of the Reducing Slag in EAF[J]. SEAISI Quarterly, 2006, 35(4): 32-38.

[5] International Iron and Steel Institute(IISI). Media Release: World Crude Steel Output Increases by 7.5% in 2007[EB]. http://www.worldsteel.org/pictures/newsfiles/2007%20Summary.pdf, 23 Jan 2008

[6] Xu Y. H., Lu W. X., Wang X. J., . Research and Development in Activation of Steel Slag Activity[J]. Journal of Shanghai University(Natural Science), 2004, 10(4): 91-95.

[7] Hwang C. L., Chiang C. C. The Study on Partial Replacement of Portland Cement with EAF Slag in Concrete[J]. SEAISI Quarterly, 2006, 35(4): 39-43.

[8] Manso J. M., Gonzalez J. J., Polanco J. A. Electric Arc Furnace Slag in Concrete[J]. Journal of Materials in Civil Engineering, 2004, 16(6): 639-645.

[9] K S You, N I Um, G C Han, et al. Characterization of Electric Arc Furnace Slag as Construction Material[C]. Sohn International Symposium/Advanced Processing of Metals and Materials (vol.1). Thermo and Physicochemical Principles: Non-Ferrous High-Temperature Processing, 2006: 417–420

[10] Chen M. Z., Zhou M. K., Wu S. P. Optimization of Blended Mortars Using Steel Slag Sand[J]. Journal of Wuhan University of Technology-Mater.Sci.Ed., 2007, 22(4): 741-744.

[11] Mindess S., Young J. F., Darwin D. Concrete, Second Edition (2003) [M], 2003 NJ Pearson Education, Inc. 102-106.

[12] Ni W., Wang E., Li J. P., . Cementing Properties of Steel Slag Activated by Sodium Silicates and Sodium Hydroxide[ J]. Journal of University of Science and Technology Beijing, 2005, 12(5): 464-468.

[13] M H Zhang, M X Jiang. Preparation of White Cement Using Reducing Slag of EAF[C]. International Symposium on Global Environment and Iron and Steel Industry (ISES ’98), Beijing, 1998: 306–308