利用自主研发的二次炭化热压型煤成型试验装置，在炭化温度分别为250、300、350和400 ℃条件下制备了二次炭化型煤试件，采用扫描电镜、核磁共振、比表面和孔径分布分析仪对热压型煤进行了测试分析，研究炭化温度对热压型煤吸附特性、孔隙发育及微观结构的影响。结果表明：随着炭化温度的升高，二次炭化型煤的水分逐渐降低，灰分和固定碳含量逐渐升高，挥发分先升高后降低，密度先增大后减小；煤样在热解过程中会形成胶状物质并均匀分布在煤粒表面，并固化填充煤粉颗粒间隙，随着温度的进一步升高，煤样表面由光滑完整的层状结构转变为碎块结构；原煤中小孔占比最多，随着温度的升高二次炭化型煤小孔占比呈现先增加后减少的趋势，中大孔占比呈现先减少后增加的趋势；在300 ℃条件下的二次炭化型煤与原煤试件都以吸附孔为主，且孔隙之间连通性较差，随着温度继续升高后，二次炭化型煤以渗流孔为主，吸附孔相对减少；原煤试样和二次炭化型煤的等温吸附线符合IV型等温吸附线，原煤和二次炭化型煤的各孔径段比表面积分布较均匀，都呈单峰分布，随着炭化温度的升高，二次炭化型煤的比表面积呈现出先增大后减小的趋势，平均孔径呈现出先减小后增大的趋势，最大吸附量呈现先增加后减少的趋势。

The secondary charred coal specimens were prepared at the charring temperatures of 250,300,350 and 400 ℃ using the self-developed secondary charred hot-pressed coal briquette specimens(CBS) forming test equipment,and were tested and analyzed by scanning electron microscope,nuclear magnetic resonance,specific surface and pore size analyzer to study the effects of charring temperature on the adsorption characteristics,pore development and microstructure of CBS The results showed that：with the increase of charring temperature,the moisture of CBS gradually decreased,the ash and fixed carbon content gradually increased,the volatile matter first increased and then decreased,and the density first increased and then decreased; the CBS formed gelatinous substances and uniformly distributed on the surface of coal particles during the pyrolysis process,and solidified to fill the interstices of pulverized coal particles,and with the further increase of temperature,the surface of CBS changed from smooth and complete lamellar structure to fragmented The percentage of small pores in raw coal specimens(RCS) is the largest,and the percentage of small pores in the secondary charred coal tends to increase and then decrease with the increase of temperature,and the percentage of medium and large pores tends to decrease and then increase; both the CBS and the RCS at 300 ℃ are mainly adsorption pores,and the connectivity between pores is poor,and the CBS is mainly percolation pores and relatively less adsorption pores after the temperature continues to increase. The isothermal adsorption lines of the RCS and the CBS under different charring temperature conditions conformed to the type IV isothermal adsorption line.The specific surface area distribution of each pore section of the RCS and the CBS is relatively uniform,with a unimodal distribution. The specific surface area of the CBS showed a trend of increasing and then decreasing with the increase of charring temperature,the average pore size showed a trend of decreasing and then increasing,and the maximum adsorption capacity showed a trend of increasing and then decreasing. 

0 引言

1 试验与方法

   1.1 型煤的制备

   1.2 SEM电镜试验

   1.3 核磁共振试验

   1.4 低温液氮吸附测试

2 试验结果与分析

   2.1 煤样基础参数

   2.3 核磁共振试验

   2.4 低温液氮吸附

3 结论