Figure 2.5 shows the DTG curves of

Figure 2.5 shows the DTG curves of 11 kinds of coal gangue samples. It can be seen from Figure 2.5 that the DTG curve of coal gangue exhibits different characteristics. S1, S3, S4, S7, S8, S9, and S10 have only one obvious weightless peak. This result is similar to the results of other literatures, and is most likely The reason is that the ignition of volatiles causes the ignition of fixed carbon, so the combustion of volatiles and the combustion of fixed carbon occur at the same time. However, the DTG curves of S2 and S5 have two overlapping weightless peaks, where the overlapping shoulder peak is located to the left of the main weightless peak, and the shoulder peak of the low temperature section corresponds to the ignition and combustion of volatiles, and the weightless peak of the high temperature section is mainly It is related to the pyrolysis process of fixed carbon. This phenomenon may be related to the unstable carbon-oxygen complex formed in the initial heating stage, because the unstable carbon-oxygen complex will cause the volatile matter to be released at a relatively low temperature. When the volatile matter ignites, a large amount of material will Start burning and then release more heat, so that the fixed carbon starts to ignite and burn.