A Experimental Study Of Pyrolysis For The Upgrading Of The Coal Slime At Low Temperature From Yunfei Company In Mongolia

The stockpiling of coal slime will cause environmental pollution and safety hazards. When combustion directly, there will be problems of the low utilization efficiency of heat. Slime drying test,low temperature pyrolysis test, feasibility test of char-upgrading and mechanism research are conducted in this study.In the slime drying test, the coal slime of moisture content 28.74% is shaped into balls with a diameter of 10mm~20mm, then it is dried about 10 min under 160?~210?, finally the coal slime of moisture content about 5% can be obtained.The dried coal slime is used as feed for the low temperature pyrolysis test. The pyrolysis characteristic of coal slime is studied through thermogravimetric experiments. It is found that, the reaction energy and frequency factor of pyrolysis increased with the increasing of hating rate, so appropriate improvement of hating rate during the pyrolysis process of coal slime benefits the improvement of reaction rate in the pyrolysis of coal slime. Finally, the optimum pyrolysis condition of coal slime is determined as 450? for reaction temparature and 10 min for reaction time, and under this condition, the char generated has the lowest content of carbon and highest content of oxygen, and it can be inferred that the volatile constituent has higher calorific value.Due to the relatively higher ash content of char generated under the condition of 450?-10 min,upgrading feasibility study is conducted. The optimum reagent system determined for flotation is kerosene 1200g/t, triton X-100 200g/t, octanol 100g/t, and clean coal of ash content 21.09%, yield75.67%, combustible recovery 79.07% can be obtained.The char of-1.0g/cm3 has high ash content reached up to 26.46% under the condition of 450?-10 min in the test of char-upgrading. After SEM and particle size analysis, it is found that the yield of intermediate product increased after pyrolysis, on whose surface there are many fine particles, and it has complex pore structure. After EDS detection, it is found that this kind of particles contain many fine particle components, and the product of this fraction concentrated in the-1.0g/cm3 product and flotation concentrate, which explains the abnormal phenomenon and the higher ash content of flotation concentrate.