The Research Of Lignite And Semi-coke Briquetting And Combustion Characteristics

China has abundant lignite resource, which concentrates in Northeast Three Provinces, Inner Mongolia Autonomous Region and Yunnan province. Lignite utilization includes combustion, low temperature carbonization, gasification, liquefaction, etc. The lignite combustion will still be an important aspect of lignite utilization in the future.Based on lignite and it's semi-coke from low temperature pyrolysis as raw materials, briquettes made by the high pressure molding technology are studied. It solves the problem that transportation of semi-coke and lignite are not convenient, broadens lignite and semi-coke utilization in geographical space. Compared with direct combustion of lignite, briquettes made of lignite and semi-coke can combust more efficiently with less dust pollution, which greatly reduces the environmental pollution problem caused by the direct combustion of lignite.In this study, some researches are done on molding process of briquettes of Kuazhu and Huolinhe lignite and their semi-coke in high pressure. The strength testing of briquettes is done too. On one side, the main factors and their significance which affect the strengths of briquettes are fixed by orthogonal method. On other side, it has been analyzed by single-factor experiments that how those factors impact on molding process including the semi-coke proportion, briquetting pressure, moisture content. The optimization conditions of Kuazhu lignite and semi-coke in mixed molding process are as follows:semi-coke content 20%, moisture content 20%, and briquetting pressure 100MPa. The optimization conditions of Huolinhe lignite and semi-coke in mixed molding process are as follows:semi-coke content 20%, moisture content 25%, and briquetting pressure 140MPa.Combustion characteristics of briquettes of Kuazhu lignite and semi-coke are also studied. With the moisture content of briquettes increases, the ignition temperature of coal combustion process is delayed and the weightlessness rate increases in 300℃-650℃combustion stage slightly; Along with the molding pressure increases, the ignition temperature of briquettes made of semi-coke mixed coal in combustion process is delayed and weightlessness rate is reducing, burn rate is slowing down; When the temperature increases the ignition temperature is delayed, total weightlessness rate is reducing. In the same time combustion rate is slowing down. The ignition temperature delayed with the increase of the pressure and total weightlessness rate is reducing, combustion process slowed. By thermo gravimetric analysis method the dynamic equations of mixed coal are established. Preliminary dynamic analysis is done on combustion process of briquettes of lignite and its semi-coke.