Department of Physics, Bizerte Science Faculty FSB, LPCMMA, National Research Center in Materials Sciences CNRSM (Technopole Borj Cedria), Tunis, Tunisia.
LPCMMA, National Research Center in Materials Sciences CNRSM (Technopole Borj Cedria), Tunis, Tunisia.
Environ Sci Pollut Res Int. 2024 Jun;31(28):40538-40553. doi: 10.1007/s11356-023-25594-5. Epub 2023 Mar 3.
Every day, significant quantities of solid wastes are generated in steel companies which causes environment pollution. These waste materials differ from one steel plant to other depending upon the steelmaking processes adopted and pollution control equipment installed. The most common type of solid wastes originated in steel plant are hot metal pretreatment slag, dust, GCP sludge, mill scale, scrap, etc. At present, various efforts and experiments are being carried out in order to make use of 100% solid wastes products in order to reducing cost of disposal, saving raw materials and conserving energy. Then, the purpose of our paper is the access to reuse potential of the steel abundant mill scale for sustainable industrial applications. This material is a very valuable industrial waste due to its richness in iron (about 72% Fe), chemical stability, and variable usage in multiple fields which implies that it can bring social and environmental benefits. This work aims to recover Mill scale and reuse it to synthesize three iron oxide pigments; hematite (α-FeO, red color), magnetite (FeO, black color), and maghemite (γ-FeO, brown color). To achieve this objective, Mill scale needs to be refined and granted to react with sulfuric acid to obtain ferrous sulfate FeSO.xHO which is used to produce hematite by calcination between 600 and 900 °C, then, magnetite by reduction of hematite using a reducing agent at 400 °C and maghemite from a thermal treatment of magnetite at 200 °C. It was shown within the experiments that the mill scale contains between 75% and 86.66% of Fe and a uniform distribution of particles size with a low span. That gave red particles size (0.18-0.193 µm) and specific surface area SSA: 6.12 m/g, black particles sizes (0.2-0.3 µm) and SSA 4.92 m/g, brown particles size (0.18-0.189 µm) and SSA 6.32 m/g. The results revealed that the mill scale was successfully converted into pigments with good qualities. So, it is recommended to work from the beginning at synthesis hematite by copperas red process and then magnetite and maghemite in order to control shape of magnetite and maghemite (spheroidal) to get the best results economically and environmentally.
每天，钢铁公司都会产生大量的固体废物，造成环境污染。这些废物的种类因采用的炼钢工艺和安装的污染控制设备而异。钢铁厂最常见的固体废物类型有：铁水预处理渣、粉尘、GCP 污泥、轧钢厂氧化皮、废料等。目前，为了降低处置成本、节约原材料和节约能源，正在进行各种努力和实验，以利用 100%的固体废物产品。因此，我们的论文旨在探索钢铁厂丰富的轧钢厂氧化皮的再利用潜力，实现可持续的工业应用。由于其丰富的铁含量（约 72%Fe）、化学稳定性以及在多个领域的多种用途，轧钢厂氧化皮是一种非常有价值的工业废物，这意味着它可以带来社会和环境效益。这项工作旨在回收轧钢厂氧化皮并将其重新用于合成三种氧化铁颜料；赤铁矿（α-FeO，红色）、磁铁矿（FeO，黑色）和磁赤铁矿（γ-FeO，棕色）。为了实现这一目标，需要对轧钢厂氧化皮进行精炼，并与硫酸反应生成硫酸亚铁 FeSO.xHO，然后通过在 600 至 900°C 之间煅烧硫酸亚铁来生产赤铁矿，接着通过在 400°C 下使用还原剂还原赤铁矿来生产磁铁矿，最后通过在 200°C 下对磁铁矿进行热处理来生产磁赤铁矿。实验表明，轧钢厂氧化皮中含有 75%至 86.66%的 Fe，并且颗粒尺寸分布均匀，跨度较低。这使得红色颗粒尺寸（0.18-0.193μm）和比表面积 SSA：6.12m/g，黑色颗粒尺寸（0.2-0.3μm）和 SSA 4.92m/g，棕色颗粒尺寸（0.18-0.189μm）和 SSA 6.32m/g。结果表明，轧钢厂氧化皮成功转化为质量较好的颜料。因此，建议从合成赤铁矿的铜铁矾法开始，然后合成磁铁矿和磁赤铁矿，以控制磁铁矿和磁赤铁矿的形状（球形），从而在经济和环境方面取得最佳效果。
