Study on the release characteristics of chlorine in coal gangue under leaching conditions of different pH values
| Autor: | Xinrui Li, Lan Yang, Bingxian Peng, Weihua Zhao |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
020209 energy
General Chemical Engineering Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology 010501 environmental sciences engineering.material 01 natural sciences chemistry.chemical_compound 0202 electrical engineering electronic engineering information engineering Chlorine Kaolinite Organic matter 0105 earth and related environmental sciences chemistry.chemical_classification Aqueous solution business.industry Organic Chemistry Coal mining Fuel Technology chemistry Illite engineering Carbonate Pyrite business Nuclear chemistry |
| Zdroj: | Fuel. 217:427-433 |
| ISSN: | 0016-2361 |
| DOI: | 10.1016/j.fuel.2017.12.123 |
| Popis: | A series of leaching experiments were carried out for evaluation of release behavior of Cl in Chinese coal gangue from Yangquan Coal Mine in Shanxi province under different pH conditions (pH = 2.6, 4.2, 6.5, 8.1, respectively) and different leaching durations (up to 105 h). The modes of occurrence of Cl in the coal gangue and its post-leached residues were extracted with sequential chemical extractions; chlorine in solution was determined using IC (ion chromatography); chemical and mineralogical compositions in coal gangue and the post-leached residues were determined by XRD (X-ray diffraction), XRF (X-ray fluorescence spectrum) and FT-IR (Fourier infrared spectrum). The results indicated that kaolinite, quartz, calcite, pyrite and illite were the predominant minerals in coal gangue with a certain amount of organic matter and a little mica. Chlorine in coal gangue occurred in a descending order of significance, as forms of organic matter (P5), Fe-Mn oxides (P4), water-soluble (P1), residue (P6), carbonate (P3), and exchangeable (P2), which accounted for 41.56%, 37.87%, 14.65%, 3.26%, 1.33% and 1.31%, respectively. With the rise of acidity of leaching solution, the reaction rates of most of matrix compositions in coal gangue increased, and more Cl was leached out in a shorter time. Under the condition of pH 2.6, 4.2, 6.5 and 8.1 and leaching duration up to 105 h, the leaching rate of Cl were respectively 57.21% (11.98%, 1.31%, 1.33%, 23.03% and 20.06% for P1, P2, P3, P4 and P5, respectively), 35.97% (8.18%, 1.31%, 0.78%, 14.77% and 10.91% for P1, P2, P3, P4 and P5, respectively), 26.65% (7.52%, 1.31%, 0.42%, 9.87% and 7.53% for P1, P2, P3, P4 and P5, respectively) and 18.98% (5.32%, 0.60%, 1.33%, 7.61% and 5.45% for P1, P2, P3, P4 and P5, respectively). Chlorine in coal gangue may pose an environmental risk with the increase of acidity of environmental aqueous solution. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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