煤炭是我国的主体能源，极大推动了我国国民经济的发展。随着优质煤炭的不断开采，细粒煤炭含量逐渐增加，煤炭分选难度增大。针对选煤厂低品质煤（末煤和煤泥）含水量高、热值低的问题，借助水分测定仪、热重气质联用仪等测试分析设备对选煤厂分选工艺中产生的低品质煤进行干燥研究，考察低品质煤炭中的水分赋存特性以及热解特性。研究了低品质煤水分脱除的温度范围，揭示了低品质煤炭干燥的最佳条件。研究了煤炭的物质分解温度，揭示了不同阶段的物质热解过程。通过复合式干法分选机探究振动频率对6～0.5 mm原煤分选效果的影响。结果表明：在末煤和煤泥中，以外水形式赋存的水分质量分数分别为17.84%和39.20%，以内水形式赋存的水分质量分数分别为10.97%和9.54%，煤泥外水含量高于末煤，两者内水含量相似。热重分析表明，热解过程可分为3个阶段，101.9 ℃前为水分逸出阶段，煤中仅有少部分物质发生热解。煤中大分子分解的临界温度为305.7 ℃，末煤和煤泥中的大分子逐渐热解，质量逐渐降低。对6～0.5 mm煤炭进行复合式干法分选机分选试验，振动频率为36 Hz时，精煤产率为45.48%，灰分为10.36%，有效实现低品质煤提质降灰。

Coal is the main energy in China,which has greatly promoted the development of national economy. With the exploitation of high-quality coal,the content of fine coal and the difficulty of coal washing increase gradually. For the problem of low-quality coal (fine coal and slime) with high water content and low calorific value in coal preparation plant,the drying research was conducted by moisture meter,thermogravimetric-gas chromatograph-mass spectrometer instrument. The moisture occurrence characteristics and pyrolysis characteristics were examined,the temperature ranges for moisture removal were studied,and the best condition of low-quality coal drying was revealed. The decomposition temperature of coal was studied,and the pyrolysis process at different stages was revealed. The influence of vibration frequency on the separation effect of 6-0.5 mm coal was investigated by compound dry separator. The results show that for the fine coal and slime,the external water content are 17.84% and 39.20%,and the internal water content are 10.97% and 9.54%,respectively. The external water content of slime is higher than that of fine coal,and the internal water content is similar. The pyrolysis process can be divided into three stages. Water escapes before 101.9 ℃,and the critical temperature for the decomposition of macromolecules in coal is 305.7 ℃. For the 6-0.5 mm coal,when the vibration frequency of compound sparator is 36 Hz,the clean coal yield is 45.48% and the ash content is 10.36%, which effectively realizes the quality improvement and ash reduction of low-quality coal.

0 引言

1 原煤性质及工艺分析

2 低品质煤脱水提质

   2.1 低品质水分赋存及煤热解特性

   2.2 低品质煤脱水提质

3 低品质煤脱灰提质

   3.1 原煤性质

   3.2 复合式干法分选机分选试验

4 结论