Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6632039 | Fuel | 2018 | 7 Pages |
Abstract
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 (pHâ¯=â¯2.6, 4.2, 6.5, 8.1, respectively) and different leaching durations (up to 105â¯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 105â¯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.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Bingxian Peng, Xinrui Li, Weihua Zhao, Lan Yang,