Luoyang Yunxuan, Wang Hua, Li Jian, Chen Bi, Li Xia, Guotao Zhang
College of Chemistry and Chemical Engineering, Yulin University, Chongwen Road No.4, Yulin City, 719000, Shaanxi Province, China.
Shaanxi Provincial Key Laboratory of Clean Utilization of Low-Modified Coal, Yulin University, Yulin City, 719000, China.
Sci Rep. 2024 Sep 11;14(1):21177. doi: 10.1038/s41598-024-72114-7.
The increasing amount of coal gasification fine slag (CGFS) necessitates its resource utilization. CGFS, mainly composed of porous carbonaceous particles and partially fused spherical or agglomerated ash particles, is an inexpensive and high-quality raw material for preparing adsorbent materials. However, the challenge remains in developing a simple, low-cost, and environmentally friendly method to produce high-performance porous materials from CGFS. In this study, a one-step treatment method using 2 mol/L nitric acid under hydrothermal conditions was proposed for CGFS. The adsorbent material (CGFS-2 M) prepared under a solid-liquid ratio of 2:5 and an initial concentration of 200 mg/L methylene blue (MB) exhibited an equilibrium adsorption capacity as high as 210.20 mg/g. The excellent adsorption performance of CGFS-2 M can be attributed to several factors: acid leaching for mineral removal and pore formation, resulting in a specific surface area and total pore volume 2.2 and 1.6 times that of untreated CGFS, respectively, and an optimized mesoporous pore size distribution favorable for MB adsorption; optimal mineral removal and a well-defined carbon microcrystal structure providing more space for MB adsorption; nitric acid treatment increasing the surface oxygen content and hydrophilicity, enhancing its ability to remove MB. The synergistic effect of pore structure improvement and surface modification indicates a feasible research direction for enhancing the performance of CGFS-based adsorbent materials. These results provide theoretical support for the development of efficient CGFS-based adsorbents.
煤气化细渣（CGFS）产量的不断增加使其资源利用成为必要。CGFS主要由多孔碳质颗粒和部分熔融的球形或团聚灰分颗粒组成，是制备吸附材料的廉价且优质的原材料。然而，开发一种简单、低成本且环保的方法以从CGFS制备高性能多孔材料仍然面临挑战。在本研究中，提出了一种在水热条件下使用2 mol/L硝酸对CGFS进行一步处理的方法。在固液比为2:5且亚甲基蓝（MB）初始浓度为200 mg/L的条件下制备的吸附材料（CGFS-2M）表现出高达210.20 mg/g的平衡吸附容量。CGFS-2M优异的吸附性能可归因于几个因素：酸浸用于去除矿物质和形成孔隙，导致比表面积和总孔体积分别是未处理CGFS的2.2倍和1.6倍，以及有利于MB吸附的优化介孔孔径分布；最佳的矿物质去除和明确的碳微晶结构为MB吸附提供了更多空间；硝酸处理增加了表面氧含量和亲水性，增强了其去除MB的能力。孔结构改善和表面改性的协同效应表明了提高基于CGFS的吸附材料性能的可行研究方向。这些结果为开发高效的基于CGFS的吸附剂提供了理论支持。
