Toxics
·
2022
·Vol. 11
·期 1
·20
·
IF 4.472
Hongyou Wan,Chen Wang,Lin Gong,Xinfeng Zhu,Jingwei Yan,Jiajia Lu,Wei Zhang
The generation and accumulation of discarded coal gangue (CG) have severe environmental impacts. CG can adsorb other pollutants in the aquatic environment. However, previous studies have not assessed whether CG can adsorb the emerging contaminant tetracycline hydrochloride (TC). Here, discarded CG taken from a mine was pretreated by crushing, cleaning, and sieving and subsequently applied to the adsorption of TC. The adsorption studies were carried out by batch equilibrium adsorption experiments. Our findings indicated that the adsorption behavior could be accurately described using the quasi-first order kinetic and Langmuir adsorption isotherm models, indicating that monolayer adsorption was the main mechanism mediating the interaction between CG and TC. The adsorption process was classified as a thermodynamic endothermic and spontaneous reaction, which was controlled by chemical and physical adsorption, including electrostatic interaction and cation exchange. The pH of the solution had a great influence on the TC adsorption capacity of GC, with higher adsorption occurring in acidic environments compared to alkaline environments. This was attributed to the changes in CG Zeta potential and TC pKa at different pH conditions. Collectively, our findings demonstrated the potential applicability of discarded CG for the adsorption of TC and provided insights into the adsorption mechanisms.Keywords:natural coal gangue;spent coal-associated waste;removal;tetracycline hydrochloride;antibiotics pollutant;water environment
研究领域:
环境科学
·
污染控制
·
吸附机制研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Coal Preparation and Utilization
·
2025
·
IF 2.1
Shengchao Yang,Sheng Dong,Jinpeng Qiao,Chao Kang,Yuqian Zhao,Yanze Wang,Jianrong Liu,Chenlong Duan,Sabereh Nazari,Miao Pan
Aiming at the problems of high quartz content, high ash content and difficult leaching of aluminum and gallium in some coal gangue, NaF-strengthened coal gangue calcination-hydrochloric acid leaching process was adopted, and the occurrence state of gallium in coal gangue was explored. The residue was analyzed by XRD and SEM, and the mechanism of NaF-strengthened coal gangue acid leaching was explored. The results show that the addition of m (NaF): m (coal gangue) = 0.06 can increase the leaching rate of aluminum in coal gangue from 33.72% to 62.03%, and the leaching rate of gallium from 43.17% to 70.15%. NaF as an additive can react with hydrochloric acid to form HF to destroy the coal gangue structure, so that hydrochloric acid can react with metakaolinite inside the quartz accumulation layer, which improves the leaching rate of aluminum and gallium. Finally, the process factors were studied separately to reveal the pattern in response to them, and it was found that the acid leaching reaction was greatly affected by internal diffusion, which provided a reference for the subsequent complexation adsorption of gallium.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Minerals
·
2022
·Vol. 12
·期 8
·994
·
IF 2.818
Qiuyu Zeng,Jun Xie,Wei Zhou,Jinbo Zhu,Liangliang Liu,Jianqiang Yin,Wenliang Zhu
The distortion process of kaolinite annealed from 25 °C to 550 °C for different holding times can be characterized using a thermogravimetric/differential scanning calorimeter (TG/DSC) for thermal analysis, X-ray diffraction (XRD) for establishing the crystal structure, the Fourier transform infrared spectrum (FTIR) for identifying the functional groups, and a scanning electron microscope (SEM) for establishing the microstructure. Dehydroxylation is the main reaction during annealing from 25 °C to 550 °C and leads to kaolinite crystal distortion. A stable crystal structure during distortion was obtained by optimizing the bulk phase with quantum chemistry. Then, the crystal structure was studied by using ab initio multiple scattering calculations for X-ray absorption of the fine structure (XAFS). The results of X-ray absorption near the edge structures (XANES) determined that peak shifts and intensity phases slightly increased. The crystal structure distortion of kaolinite during annealing can be explained by the experimental and simulation results. This work provides theoretical support for identifying kaolinite with different degrees of distortion and has the potential for further developments in coal gangue separation.Keywords:coal and gangue;kaolinite;distortion;multiple scattering computation
研究领域:
矿物学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Lina Han,Weiguo Ren,Bing Wang,Xingxing He,Lingjun Ma,Qihuang Huo,Jiancheng Wang,Weiren Bao,Liping Chang
In this work, a novel method is introduced to activate coal gangue (CG) for extraction of Si and Al species. The activation experiments were carried out using a stainless steel tube reactor (17 mL) and an autoclave reactor (1000 mL). Firstly, CG was activated by supercritical water added with alkali. It was found that the kaolinite phase of raw CG could be transformed into cancrinite, sodalite and kalsilite by using NaOH, Na 2 CO 3 and KOH as activators, respectively. Secondly, silica (SiO 2 ) and alumina (Al 2 O 3 ) were prepared by acid and alkali combination method. The extraction rates of Al 3+ and Si 4+ from the activated CG using KOH as activator were as high as 78.9% and 69.2%, respectively. The purity of SiO 2 and Al 2 O 3 products were 96.2% and 99.3%, respectively. The as-synthesized SiO 2 both from 17 mL and 1000 mL reactor exhibited very high specific surface areas of 710.0 m 2 ·g −1 and 872.8 m 2 ·g −1 , respectively. In addition, the SiO 2 after hydrophobic modification displayed excellent absorption selectivity for xylene.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Qingshan Zhang,Xinxin Yan,Yaoli Peng
Bioleaching of effective silicon represents a crucial method for the green and efficient utilization of coal tailings (CTs). However, the influence of heavy metals present in coal tailings on this process cannot be underestimated. This study investigates the effects of five high-concentration heavy metal elements (Pb, Zn, Cu, Cr, and Ni) in CTs on the biological characteristics and leaching processes of Bacillus mucilaginosus ( B.M. ). The results indicated that varying concentrations of heavy metal elements significantly influenced the bioleaching of effective silicon by B.M. . Kinetic analysis revealed that the leaching process predominantly adhered to a chemical reaction-controlled mechanism. Changes in the functional groups, mineral composition, and morphology of the CTs surface demonstrated that chromium and nickel exerted a negligible effect on leaching effectiveness, with effective silicon concentrations of 315.71 mg/L and 322.62 mg/L, respectively. The activity of B.M. induced surface erosion of CTs, disrupting the crystal structure of silicon-bearing minerals and facilitating the conversion of silicon in quartz and kaolinite to effective silicon. In contrast, lead, zinc, and copper significantly inhibited B.M. , hindering effective erosion of CTs and resulting in lower effective silicon leaching concentrations of 129.65 mg/L, 142.68 mg/L, and 135.70 mg/L, respectively. Therefore, this study summarizes the effects of various heavy metal elements on the bioleaching of effective silicon by B.M. , providing a scientific foundation for the environmentally sustainable utilization of CTs.
研究领域:
微生物学
·
环境科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2025
·Vol. 15
·期 5
·321
·
IF 4.3
Boyang Xu,Jie Chen,Kai Wang,Pengfei Li,Le Kang,Huiling Du,Qianqian Liu,Xiaoqing Lian
The accumulation of organic pollutants and solid waste is one of the major environmental challenges faced globally. Establishing an efficient recycling system for solid waste and designing cost-effective, high-performance photocatalysts are urgent tasks for the removal of organic pollutants from water. This study utilizes coal gangue as the precursor to synthesize a coal gangue-based phosphorus–silicon–aluminum molecular sieve (SAPO-5) via hydrothermal synthesis. The resulting material was then composited with bismuth oxybromide (BiOBr) to form a novel BiOBr/coal gangue-based SAPO-5 nanocomposite. When the mass ratio of BiOBr to coal gangue-based SAPO-5 molecular sieve is 0.3, the synthesized nanocomposite exhibits excellent adsorption and photocatalytic performance for the removal of methylene blue, achieving a removal rate of 97.8% and the mineralization rate of 57.4% within 30 min. The superior performance can be attributed to the optimal pore size, rapid charge transfer rate, and high photogenerated charge density of the BiOBr/coal gangue-based SAPO-5 nanocomposite. The novel BiOBr/coal gangue-based SAPO-5 molecular sieve nanocomposite catalyst presents a new approach for the harmless treatment of organic dye wastewater and the high-value utilization of coal gangue.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Minerals
·
2022
·Vol. 12
·期 6
·763
·
IF 2.818
Xiao Wang,Jixiong Zhang,Meng Li,Feng Gao,Abbas Taheri,Binbin Huo,Ling Jin
The cemented backfill (CB) utilizing coal gangue (CG) and fly ash (FA) is widely applied in coal mines. However, the bleeding and shrinkage of CB leads to insufficient contact with surrounding rock, which is not beneficial for controlling roof subsidence and even stope stability. Herein, a cemented foam backfill (CFB) formulation is demonstrated, employing hydrogen dioxide (H2O2) as a chemical foaming agent. The cement and FA show noticeable inhibiting effects on volume expansion due to the network formed by their hydrates. Moderately lower cement, FA, and solid concentration are beneficial to improve volume increment and prolong expanding duration. A foaming coefficient (k) is proposed in theory to evaluate the foaming efficiency. Thekemvalues, determined by volume evolution experiments of CFB slurries, provide a calculation basis for the needed dosage of H2O2solution targeting specific volume increment. CFB specimens with expanding ratios of 21%~103% and densities of 994~592 kg/cm3were prepared, with an actual foaming coefficient of 52.40 cm3/g and uniaxial compressive strength (UCS) of 0.32~0.55 MPa. The mass of H2O2solution was 1.9%~11.3% of cement and 0.29%~1.67% of total solid materials by weight. The UCS decline compared to CB was attributed to rich pores observed by CT and carbonation indicated by X-ray diffraction (XRD).Keywords:backfill mining;coal gangue;hydrogen dioxide;chemical foam
研究领域:
矿业工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Chenguang Yang,Jianqiang Yin,Liqin Wu,Qiuyu Zeng,Liwei Zhang
For coal and gangue, intelligent sorting processes for separation, the use of coal and gangue mineral components with different fundamental differences, and the study of different properties of minerals and coal with different scales and density regarding the gray value change law are presented. The results show that the gray value of single minerals and mixed minerals gradually decreases with the increase of their thickness and density. The greater the density of minerals, the smaller the gray value at the same thickness, and the same rule applies to different coal ranks. Via regression analysis methods, the values of the regression equation parameter a of pure minerals for graphite, quartz, kaolinite, and montmorillonite are 59.25, 65.69, 61.61, and 58.02 in the high-energy region, respectively. In the low-energy region, they are 174.95, 177.31, 186.95, and 161.81. For the regression equation parameter of mixed minerals in the form of two mixed minerals (graphite and quartz, kaolinite, or montmorillonite) and three kinds of mineral mixing (graphite–kaolinite and quartz; graphite–montmorillonite and quartz; graphite–kaolinite and montmorillonite), the gray values are 151.12, 156.00, 153.13,152.43, 152.98, and 151.98 in the high-energy region, respectively; in the low-energy region, they are 193.34, 201.34, 192.93, 191.26, 194.68, and 193.08. The phenomenon for the gray range of two kinds of single minerals locates in the range of mixed minerals that was formed from a single mineral observed after the regression equation of mixed mineral was verified by a single mineral, which agrees with the X-ray recognition pattern. In the end, as the density of coking coal, fat coal, and gas coal increases, the gray value decreases, which was in agreement with single- and mixed-mineral analyses.
研究领域:
矿业工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Shengchao Yang,Jinpeng Qiao,Chao Kang,Mengyao Sun,Sheng Dong,Yuqian Zhao,Wenhao Sun,Yundong Yang,Chenlong Duan
Gallium is a strategic key metal, and its demand is increasing. Coal gangue is a kind of mine solid waste with huge reserves. Extracting gallium from coal gangue can realize high value-added utilization of solid waste. In this study, toluene-2,4-diisocyanate and polyether polyol were used to synthesize a new high-performance polyurethane foam adsorbent under triethanolamine catalytic. The feasibility of preparing polyurethane foams with different raw material ratios and the differences in their physicochemical properties were explored, and the optimal ratio of polyether polyol to toluene-2,4-diisocyanate was found to be 3.5. Adsorption tests of gallium ions in gangue acid leachate were carried out to determine the feasibility of adsorption of gallium by polyurethane foam in low gallium concentration solution, and the adsorption rate was 83.90% under the optimal conditions. The adsorption mechanism of polyurethane foam was revealed, indicating that Ga 3+ complexed with Cl - adsorbed on polyurethane groups (—COONH—), before adsorption need to use hydroxylamine hydrochloride to remove Fe 3+ in solution. The adsorption process can be described by pseudo-second-order kinetic model, conforms to Langmuir adsorption model, and belongs to the chemisorption. The reaction belongs to endothermic reaction. The foam still has good adsorption effect after multiple adsorptions, which opens up a new way for the recovery and utilization of gallium in coal gangue.
研究领域:
材料科学
·
环境科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Sustainable Metallurgy
·
2025
·
IF 3.2
Shao Shuang,Ma Baozhong,Wang Chengyan,Chen Yongqiang
Extracting Al from coal gangue has the double benefits of realizing the high-value application of coal gangue and mitigating the scarcity of bauxite resource. The key Al-containing minerals in coal gangue include kaolinite and boehmite, and thermal activation is pivotal for stimulating their reactivity. In this study, kaolinite and boehmite were subjected to thermal activation and acid leaching to explore the intrinsic link between their thermal evolution and leaching activity. Results showed that the phase evolution of kaolinite followed a multi-step sequential process in the order of kaolinite → metakaolinite → γ -Al 2 O 3 → mullite, and Al V in metakaolinite was highly active. For boehmite, it underwent the transformation of boehmite → γ -Al 2 O 3 → δ -Al 2 O 3 → θ -Al 2 O 3 and α -Al 2 O 3 successively. Their reactivity in descending order was γ -Al 2 O 3 > δ -Al 2 O 3 > boehmite > α -Al 2 O 3 . Furthermore, a comparative study of leaching temperature demonstrated that elevated temperature favorably strengthened the thermodynamic driving force and greatly promoted the Al extraction. This study is of some theoretical significance for guiding the thermal activation and acid leaching of coal gangue. Graphical
研究领域:
矿物加工
·
材料科学
·
冶金学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 7
·1443
·
IF 3.2
Yanshuang Chen,Yilin Chen,Hanqi Xu,Wenqi Zhao,Guodong Feng,Chunhui Xiao
The accumulation of coal gangue (CG), a byproduct of coal mining, poses severe environmental challenges. This study presents a green strategy to convert CG into high-value NaX zeolite via an alkali fusion–hydrothermal method. Through orthogonal experiments, the optimal synthesis conditions (solid–liquid ratio 1:8, crystallization temperature 110 °C, time 12 h) were identified, yielding NaX zeolite with exceptional crystallinity (98%), specific surface area (703.5 m2/g), and pore volume (0.28 cm3/g). Comprehensive characterization (XRD, SEM-EDS, BET, etc.) confirmed its structural integrity and thermal stability. The synthesized zeolite exhibited remarkable adsorption capacities for Cu2+(185.35 mg/g) and CO2(5.51 mmol/g), following the Langmuir isotherm model. This work not only addresses gangue disposal challenges but also demonstrates a cost-effective route for producing high-performance adsorbents, aligning with circular economy and carbon neutrality goals.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Huixin Zhou,Dingxun Ma,Lingwen Dai,Yichao Wang,Xiaoling Ren,Xiaozhen Liu,Xumin Li,Haijiao Xie,Xinqian Shu
Quartz (Qtz) and kaolinite (Kln) are the main siliceous minerals in coal gangue (CG), which can be converted into effective silica by mechanical activation and improve the utilization efficiency of CG in turn. This study aimed to analyze and reveal the reaction mechanism of siliceous minerals in CG under mechanical activation surface modification by experiments and DFT calculations. We showed that increasing the rotational speed and m(Al 2 O 3 /SiO 2 ) stoichiometric ratio simultaneously boosted the activation ratio of siliceous minerals, up to 3.91 %. Mechanical activation promoted the formation of oxygen vacancy structures on siliceous minerals surfaces, which aligned with the system’s activation capacity. The Exp3P2 polynomial function model best described the relationship between the rotational speed and the activation ratio of different siliceous minerals. The oxygen vacancy, S BET , rotational speed, milling temperature, m(Al 2 O 3 /SiO 2 ) stoichiometric ratio, total pore volume showed significant positive correlations with the activation ratio. First-principles calculations revealed that the oxygen defect formation energy of Kln (5.17 eV) was slightly smaller than Qtz (5.27 eV), Kln was more likely to form oxygen defects than Qtz in mechanically activated reaction. This research contributes to understanding the mechanical activation of CG into effective silica, enhancing its potential for the graded and quality-based utilization.
研究领域:
材料科学
·
矿物加工工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）