# Application of Waste Tire Carbon for Iron-Containing Dust Reduction in Industrial Processes
## 2 Materials and Methods  
### Materials  
The two kinds of IBD used in this experiment, separately, were SMTD and SDG, sourced from a steel plant. The three kinds of reductant used in this experiment separately were WT, WTC, and CC. WT was sourced from a recycling facility with 1-3 mm particle size, partially made into WTC. CC was standard commercial coke. All samples were dried, and all except WC were sieved through a 40-mesh screen. Ultimate analysis (C, H, N, and S) of the samples was measured with an elemental analyzer (Thermo Scientific Flash 2000, Waltham, MA, USA), and the chemical composition of the IBD was determined by X-ray fluorescence spectroscopy (XRF) analysis tested by Beijing Chenfei Technologies (Beijing, China), with a titration method tested by Changsha Research Institute of Mining and Metallurgy Co., Ltd. (Changsha, China) to measure the various valence state Fe contents.  
As illustrated in Tables 1 and 2, samples contained few harmful nonmetallic elements (N, S, Cl, P). The C content of CC was the highest among the reductants, ca. 88.53%, while WTC had the lowest, ca. 67.87%. The TFe content in IBD was abundant with varying valence states, and in SDG, iron predominantly existed in the divalent form. ca. 27.88%.  
X-ray diffraction (XRD) was used in this study to analyze phase changes and the crystallinity of the samples before and after reaction. Measurements were performed using an X'Pert Pro MPD diffractometer (Malvern PANalytical, Malvern, UK) with a voltage of 40 kV, current of 40 mA, scanning range from 10 to 90\({}^{\circ}\), and a scan rate of 8\({}^{\circ}\) per minute. The analysis of Figure 1 indicates that iron in SMTD and SGD primarily exists in the forms of Fe\({}_{2}\)O\({}_{3}\) and Fe\({}_{3}\)O\({}_{4}\), with no significant peaks of MFe observed, consistent with the results shown in Table 2. SMGD contains a strongly magnetic spinel phase MgFe\({}_{2}\)O\({}_{4}\)[18], while the iron in SDG is primarily in the form of Fe\({}_{3}\)O\({}_{4}\), with a relatively high Fe\({}^{2+}\) content, aligning with the 27.88% reported in Table 2. SGD is produced from the basic oxygen steelmaking process, resulting in relatively high contents of FeO and CaO, with CaO primarily existing in the forms of lime, calcite, and dolomite [19; 20]. The strongest diffraction peak of free calcium oxide (f-CaO) is observed at 20 = 38\({}^{\circ}\)[21].  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Material** & **C** & **H** & **N** & **S** \\ \hline WT & 75.01 & 6.37 & 0.66 & 2.75 \\ WTC & 67.87 & 1.62 & 0.60 & 3.94 \\ CC & 88.53 & 1.12 & 0.88 & 0.84 \\ SMTD & 1.15 & 0.05 & 0.02 & 0.72 \\ SGD & 1.09 & 0.64 & 0.14 & 0.00 \\ \hline \end{tabular}
\end{table}
Table 1: Elemental analysis of raw materials (wt%).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Material** & **Ca** & **Al** & **Mg** & **Cu** & **Cr** & **Zn** & **O** & **Si** \\ \hline SMTD & 11.75 & 1.37 & 2.19 & - & - & 0.01 & 30.11 & 2.87 \\ SGD & 11.68 & 0.16 & 3.86 & - & - & 0.18 & 19.58 & 0.72 \\ \hline
**Material** & **Cl** & **P** & **TFe** & **Fe\({}^{2+}\)** & **MFe** & & & \\ \hline SMTD & 0.14 & 0.08 & 49.32 & 2.27 & 0.34 & & & \\ SGD & 0.12 & 0.09 & 61.74 & 27.88 & 30.91 & & & \\ \hline \end{tabular}
\end{table}
Table 2: Chemical composition analysis of the IBD (wt%).