Stabilization and Crystal Characterization of Electric Arc Furnace Oxidizing Slag Modified with Ladle Furnace Slag and Alumina

Abstract

Ladle furnace slag (LFS) is a by-product of a steel plant. As the chemical composition and free lime (f-CaO) content of each batch of slag are significantly different, it is difficult to use the same operation method to recover LFS. In this study, three types of LFS were used to partially replace lime in the dephosphorization process, and the compositions were adjusted to a fixed range by adding Al2O3. This method reduced the effect of different LFS components and significantly reduced the Ca2SiO4 amount (from 31.4% to 17.1%) in the produced modified oxidizing slag. Furthermore, after dephosphorization, the X-ray diffraction (XRD) patterns of the three LFSs indicated transformation into gehlenite and wustite. The modified oxidizing slag f-CaO content was 0.41%, which was lower than that in the electric arc furnace oxidizing slag (1.2–1.4%) and the LFS (0.9–3.4%). In addition, the expansion test results of the modified oxidizing slag showed almost no expansion, which conforms to the ASTM D2940 standards; thus, this material can be used for preparing paving materials. This study provides an approach for LFS treatment that could reduce costs within the steel industry.

Assessment of Electric Arc Furnace (EAF) Steel Slag Waste’s Recycling Options into Value Added Green Products: A Review

“…Most of the global steel slag ends up being disposed of, with only a small portion recycled [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Studies have also shown that the recycling rate of steel slag is still generally much lower in Asian countries [2,[21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”

Bituminous base courses for flexible pavements with steel slags

“…Among the multiple uses of steel slag, the most widespread are: its reincorporation into the steel production process (Li et al, 2020;Varanasi et al, 2019) and its use in the construction sector, mainly as a substitute for natural aggregates and binders in the manufacture of concrete and cementitious composites (Brand and Fanijo, 2020;Piemonti et al, 2021) or bituminous mixtures (Li et al, 2018;Pasetto et al, 2017). One of the applications with the greatest potential is the incorporation of these materials in road pavements, replacing natural aggregates (Dondi et al, 2021;Maharaj et al, 2017).…”