Yadav Virendra Kumar, Gnanamoorthy Govindhan, Yadav Krishna Kumar, Ali Ismat H, Bagabas Abdulaziz A, Choudhary Nisha, Yadav Shalini, Suriyaprabha Rajendran, Islam Saiful, Modi Shreya, Cabral-Pinto Marina
Department of Microbiology, School of Sciences, P P Savani University, Kosamba, Surat 394125, Gujarat, India.
Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu, India.
Materials (Basel). 2022 Mar 3;15(5):1879. doi: 10.3390/ma15051879.
With rapid industrialization, there is an ever-increasing demand for iron oxides, calcium oxides, aluminum oxides, silica, and zeolites as raw materials for various industries, but reserves of such metal oxides are continuously diminishing. Therefore, there is an urgent need to explore new alternatives for such value-added minerals. One such material is incense stick ash (ISA), which is among the most unexplored byproducts from residential and holy places. Currently, ISA is of no use and it is disposed of in millions of tons (MTs) in rivers and other water bodies in India due to its sacred value. The major chemical composition of ISA is calcium, silica, alumina, ferrous minerals, magnesium, and traces of Na, K, P, Ti, etc. Major fractions of ISA, i.e., 50-60%, are made up of calcium and magnesium oxides; 20-30% of ISA is made up of silica, alumina, and ferrous minerals, as revealed by X-ray fluorescence spectroscopy (XRF). In the present research work, methods of recovery of value-added micro and nano minerals from ISA are suggested, using cost-effective techniques and an eco-friendly approach. Firstly, magnetic fractions were recovered by a magnetic separation method; then, alumina, silica, and calcium oxides were synthesized from non-magnetic fractions. The confirmation of the synthesized and extracted nanomaterials was done by Fourier transform infrared spectroscopy (FTIR), particle size analyzer (PSA), X-ray diffraction (XRD), field emission scanning electron microscopy with electron diffraction spectroscopy (FESEM-EDS), and transmission electron microscopy (TEM). The purity of synthesized particles varied from 40-80%. In the future, ISA will prove to be an alternative resource material for Fe, Ca, Si, C, Al, and zeolites, which will minimize solid waste pollution and water pollution arising due to the disposal of ISA into water bodies.
随着工业化的快速发展，作为各种工业原材料的氧化铁、氧化钙、氧化铝、二氧化硅和沸石的需求不断增加，但此类金属氧化物的储量却在持续减少。因此，迫切需要探索此类增值矿物的新替代品。香灰（ISA）就是这样一种材料，它是住宅和圣地最未被充分探索的副产品之一。目前，由于其神圣价值，香灰毫无用处，在印度，数百万吨的香灰被倾倒在河流和其他水体中。香灰的主要化学成分是钙、二氧化硅、氧化铝、含铁矿物、镁以及微量的钠、钾、磷、钛等。X射线荧光光谱（XRF）分析表明，香灰的主要成分，即50 - 60%，由氧化钙和氧化镁组成；20 - 30%由二氧化硅、氧化铝和含铁矿物组成。在本研究工作中，建议采用经济高效的技术和环保方法，从香灰中回收增值的微米和纳米矿物。首先，通过磁选法回收磁性部分；然后，从非磁性部分合成氧化铝、二氧化硅和氧化钙。通过傅里叶变换红外光谱（FTIR）、粒度分析仪（PSA）、X射线衍射（XRD）、场发射扫描电子显微镜与电子衍射光谱（FESEM - EDS）以及透射电子显微镜（TEM）对合成和提取的纳米材料进行确认。合成颗粒的纯度在40 - 80%之间。未来，香灰将被证明是铁、钙、硅、碳、铝和沸石的替代资源材料，这将最大限度地减少因香灰倾倒入水体而产生的固体废物污染和水污染。
