Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Hunan International Joint Lab of Mineral Materials, Central South University, Changsha 410083, China; Key Lab for Mineral Materials and Application of Hunan Province, Central South University, Changsha 410083, China.
Sci Total Environ. 2020 Sep 20;736:139483. doi: 10.1016/j.scitotenv.2020.139483. Epub 2020 May 19.
Iron tailings are fine, stable and complex materials, which are mainly composed of minerals and metal oxides. Residual silicon in iron tailings can be used to prepare mesoporous silica materials applied to energy storage, environmental protection and other fields. This paper reported a novel synthesis strategy from iron tailings to high-surface area hexagonally ordered mesoporous silica materials in an innovative non-hydrothermal system at room temperature. A pretreatment process involving acid leaching and hydrothermal alkaline reaction was vital to the successful utilization of iron tailings. X-ray fluorescence (XRF) data suggested that about 95% of the silicon of iron tailings changed to the silicate as a silicon source. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), N-adsorption-desorption isotherms, Fourier transform infrared (FTIR) spectroscopy, Thermogravimetry and differential scanning calorimetry (TG-DSC) and Si solid-state nuclear magnetic resonance (NMR) spectroscopy. The SAXRD patterns of mesoporous silica materials exhibited an intense (100) diffraction peak and two weak (110, 200) diffraction peaks, corresponding to characteristic of the ordered mesoporous lattice. TEM images further confirmed the hexagonally ordered porous structure of mesoporous silica materials. The WAXRD patterns and Si MAS NMR spectra of the samples indicated that mesoporous silica materials were composed of amorphous SiO. The obtained mesoporous silica materials had a high surface area of 1915 m/g and pore volume of 1.32 cm/g. Furthermore, the evolution from iron tailings to mesoporous silica materials was elucidated and a proposed synthesis mechanism was discussed. Collectively, these results provided an insight into efficient recycling of iron tailings and the production of advanced functional materials from solid waste.
铁尾矿是一种精细、稳定且复杂的材料，主要由矿物和金属氧化物组成。铁尾矿中的残余硅可用于制备介孔硅材料，应用于储能、环保等领域。本文报道了一种在室温下的创新非水热体系中，从铁尾矿到高比表面积六方有序介孔硅材料的新型合成策略。酸浸预处理和水热碱反应对铁尾矿的成功利用至关重要。X 射线荧光（XRF）数据表明，约 95%的铁尾矿硅转化为硅酸盐，作为硅源。采用 X 射线衍射（XRD）、透射电子显微镜（TEM）、N2 吸附-脱附等温线、傅里叶变换红外（FTIR）光谱、热重-差示扫描量热法（TG-DSC）和 Si 固态核磁共振（NMR）光谱对样品进行了表征。介孔硅材料的 SAXRD 图谱呈现出强烈的（100）衍射峰和两个较弱的（110、200）衍射峰，对应于有序介孔晶格的特征。TEM 图像进一步证实了介孔硅材料的六方有序多孔结构。样品的 WAXRD 图谱和 Si MAS NMR 谱表明，介孔硅材料由非晶态 SiO 组成。所得到的介孔硅材料具有高达 1915 m2/g 的比表面积和 1.32 cm3/g 的孔体积。此外，还阐明了从铁尾矿到介孔硅材料的演变过程，并讨论了提出的合成机制。总之，这些结果为高效回收铁尾矿和从固体废物中生产先进功能材料提供了新的见解。
