镶嵌结构沥青焦的制备与表征:重相沥青中QI含量的影响

Preparation and characterization of pitch-based mosaic coke from heavy-phase coal pitch:Effects of quinoline insoluble

镶嵌结构沥青焦作为一种特种人造炭材料,是制备高品质各向同性石墨和核石墨的重要原料。镶嵌结构沥青焦的性质在很大程度上决定了其石墨制品的质量。为进一步明确重相沥青中QI含量对其镶嵌结构沥青焦的结构及性质的影响,本研究以九种QI含量迥异的重相沥青为原料,制备了系列镶嵌结构沥青焦。利用偏光显微镜、扫描电镜、XRD、Raman光谱及分峰拟合的方法对镶嵌结构焦的微观结构进行了判定,并对九种镶嵌结构沥青焦的显微强度进行了研究。结果表明,重相沥青中QI含量越高,在液相炭化过程中越有利于镶嵌结构的生成。并且,随着重相沥青QI含量的增加,镶嵌结构沥青焦中趋于规整炭微晶含量逐渐降低,无定型炭含量逐渐增加,强度越大。当重相沥青中QI含量超过7%时,制备的镶嵌结构沥青焦中镶嵌结构总含量(细粒镶嵌、中粒镶嵌和粗粒镶嵌)超过82%,显微强度超过85%。换言之,QI含量超过7%的重相沥青是生产优质镶嵌结构沥青焦的优选原料。

Mosaic coke is a kind of special artificial carbon material,which is usually used as the raw material to produce high-quality nuclear graphite.The quality of graphite has been usually focused on the properties of mosaic cokes.In order to investigate the influence of the quinoline insoluble(QI)content of heavy-phase pitch on the micro-structure and properties of mosaic coke,9 kinds of heavy-phase pitches with varied QI contents were used as the raw materials to produce series of mosaic cokes in this study.Optical micro-scope,scanning electronic micro-scope,X-ray diffraction,Raman spectrum and curve-fitted methods were used to judge the micro-structure of 9 kinds of mosaic cokes.Also,the micro-strength of mosaic cokes was determined.The results show that the higher content of QI in heavy-phase pitch has the mosaic structure easier to be produced during the liquid-phase carbonization process.What’s more,with the increase of QI content,the content of regular carbon microcrystals decreases,but the content of amorphous carbon and micro-strength are improved.When the QI contents in the heavy-phase are higher than 7%,the derived mosaic cokes have the total contents of mosaic structure(the sum of fine mosaic structure,medium mosaic and coarse mosaic)higher than 82%and the micro-strength higher than 85%.In other words,the heavy-phase pitch with the content of QI higher than 7%is a promised raw material to produce high-quality mosaic coke.