Abstract

The reaction kinetics, activation energy, and reduction rates of different carbon reductant properties with electric arc furnace (EAF) slag determine the effectiveness of carbon in EAF steelmaking. This article investigates the interaction between slag and carbonaceous materials derived from palm char and coke. Palm shells were converted into palm char using chemical activation method (phosphorus acid, H₃PO₄) and pyrolyzed at 450 °C for 2 h in a horizontal tube furnace. Then, all the carbonaceous materials were mixed with iron oxide from slag with mass ratio of 1:3.73. The reduction reaction was carried out in a horizontal tube furnace at different temperature ranges of 1250–1550 °C under argon gas to understand the reaction kinetics, activation energies, and reduction rates of iron oxide from EAF slag with palm char and coke. All iron oxides in EAF slag were completely reduced into metallic iron at 1550 °C for both reductants. The phase and quantity of reduced iron were confirmed by Rietveld refinement method using X-ray diffraction (XRD) pattern and energy-dispersive X-ray spectroscopy (EDX). Palm char/slag has lower activation energy value, E (38.52 kJ/mol), than coke/slag (47.75 kJ/mol). The reaction rate of palm char was found faster (4.99 × 10^–5 mol/cm² s) than coke due to larger specific surface area, higher pore volume, amorphous carbon structure, and higher fixed carbon with high volatile content leading to lower activation energy, thus accelerating the iron oxide reduction rates. This finding forms the basic understanding of the reaction between EAF slag and carbonaceous materials for future research on the production of palm char as a feasible carbon reductant in EAF steelmaking.

Graphical Abstract

中文翻译：

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电弧炉炼钢渣中焦炭和焦炭与氧化铁的反应动力学

摘要

电弧炉（EAF）炉渣的反应动力学，活化能和不同碳还原剂特性的还原率决定了碳在EAF炼钢中的有效性。本文研究了炉渣与棕榈炭和焦炭衍生的含碳物质之间的相互作用。使用化学活化方法（亚磷酸，H ₃ PO ₄）并在水平管式炉中在450°C的温度下热解2小时。然后，将所有含碳物质与炉渣中的氧化铁混合，质量比为1：3.73。还原反应在水平管式炉中在氩气下于1250–1550°C的不同温度范围内进行，以了解反应动力学，活化能以及电弧炉渣与棕榈炭和焦炭的氧化铁还原速率。在1550°C下，两种还原剂将EAF炉渣中的所有氧化铁完全还原成金属铁。通过使用X射线衍射（XRD）图和能量色散X射线光谱法（EDX）的Rietveld精制方法来确认还原铁的相和数量。棕榈炭/矿渣具有较低的活化能值E（38.52 kJ / mol），而不是焦炭/矿渣（47.75 kJ / mol）。发现棕榈炭的反应速率（4.99×10 ^–5  mol / cm ²  s）比焦炭快，这是因为比表面积更大，孔体积更大，无定形碳结构以及较高的固定碳和较高的挥发性含量导致较低的活化度能量，从而加速了氧化铁的还原速率。该发现形成了对电弧炉炉渣与碳质材料之间反应的基本理解，以用于未来研究在电弧炉炼钢中用作可燃碳还原剂的棕榈炭的生产。

图形概要