## 3 Results  
### Analysis of the Main Components of Coal and Jet  
The water content of coal and jet is very low, which is quite lower than the coal's water content. The maximum moisture content of coal shall not exceed 5%, while the maximum moisture content of jet shall not exceed 3%. Specifically, the moisture content of Qianjing jet 1 is 0.7%, Qianjing jet 2 is 0.6%, Wangping jet 1 is 0.58%, and Fushun Yaokeng jet is 2.4%. In comparison, the moisture content of Qianjing Coal 1 is 2.3%, Qianjing Coal 2 is 3.74%, Wangping Coal is 1.19%, and Fushun Yaokeng coal is 4.17%. Except for the ash content of Qianjing No. 11 coal 2 and Qianjing jet 2, and the ash content of Fushun Yaokeng coal and Fushun Yaokeng jet are similar, the ash content of jet in other areas is about half of that of coal. The ash content of Qianjing Coal 1 is 12%, Qianjing Coal 2 is 11.4%, Wangping Coal is 10.28%, Fushun Yaokeng Coal is 3.43%, and Qianjing No. 11 Coal 1 has an ash content of 28%. Qianjing No. 11 coal 2 is 12.38%, Wangping No. 8 coal is 10.28%, and Fushun Yaokeng coal is 3.71%. The volatile content of coal and jet is obviously different, and the volatile content of jet is 10-40% higher than that of coal. The volatile matter content of Qianjing Coal 1 is 61.5%, Qianjing Coal 2 is 74.61%, Wangping Coal is 70.4%, Fushun Yaokeng Coal is 58.38%, and Qianjing No. 11 Coal 1 has a volatile content of 38.6%, Qianjing No. 11 coal 2 is 32%, Wangping No. 8 coal is 29.93%, and Fushun Yaokeng coal is 45%. The apparent density of jet is smaller than that of coal, the apparent density of jet is about 1.2, while the apparent density of coal is about 1.3-1.6. The apparent density of Qianjing Coal 1 is 1.23, Qianjing Coal 2 is 1.2, Wangping Coal is 1.2, Fushun Yaokeng Coal is 1.24, and Qianjing No. 11 Coal has an apparent density of 1.42 and Qianjing No. 11 Coal 2 is 1.5, Wangping No. 8 coal is 1.65, and Fushun Yaokeng coal is 1.32. The fixed carbon content of jet is at least 10% lower than that of coal, and the maximum fixed carbon content is 37%, while the fixed carbon content of coal is more than 30%. The fixed carbon content of Qianjing Coal 1 is 25.6%, Qianjing Coal 2 is 13%, Wangping Coal is 19%, Fushun Yaokeng Coal is 37%, and Qianjing No. 11 Coal 1 has a fixed carbon content of 40%. Qianjing No. 11 coal 2 is 49%, Wangping No. 8 coal is 30%, and Fushun Yaokeng coal is 43%. There is little difference in oxygen absorption between jet and coal. The oxygen absorption capacity of Qianjing Coal 1 is 0.56, Qianjing Coal 2 is 0.76, Wangping Coal is 0.7, Fushun Yaokeng Coal is 0.82, and Qianjing No. 11 Coal 1 has an oxygen absorption capacity of 0.61 and Qianjing No. 11 Coal 2 is 0.73, Wangping No. 8 coal is 0.61, and Fushun Yaokeng coal is 0.8. The ignition temperature of jet is between 260 and 330 \({}^{\circ}\)C, which is lower than that of coal, and it is easy to occur naturally. The ignition temperature of Qianjing Coal 1 is 330 \({}^{\circ}\)C, Qianjing 2 is 280 \({}^{\circ}\)C, Wangping Coal is 300 \({}^{\circ}\)C, Fushun Yaokeng Coal is 260 \({}^{\circ}\)C, and Qianjing No. 11 Coal 1 has an ignition temperature of 400 \({}^{\circ}\)C. No. 11 coal 2 is 300 \({}^{\circ}\)C, Wangping No. 8 coal is 330 \({}^{\circ}\)C, and Fushun Yaokeng coal is 270 \({}^{\circ}\)C.  
It can be seen that the result in Table 1 demonstrates that the physical and chemical parameters of coal from each coal seam and jet are quite different. The moisture content, ash content, density and ignition point of jet are all lower than coal, and jet and coal have significant differences in volatile matter content and fixed carbon content. The volatile matter content of jet is much higher than that of coal and the fixed carbon content of coal is much lower than that of jet. Jet is easy to spontaneously combust, with greater hardness and better elasticity. Due to the variations in the depositional environment of various coal fields, the physical and chemical parameters of coal and jet differ greatly.