Refined coal tar pitch is considered as a promising material for the production of needle coke owing to its excellent physical–chemical properties. It was generally accepted that the basic properties of refined coal pitch played a vital role in affecting the resulting quality of the derived needle coke during the delayed coking process. Our previous research showed that an f_a of 0.95–0.98 of refined coal pitch was optimal and produced needle coke of the highest quality. What is more, we found that the contents of β resin in refined pitch were also important to the properties (microstructure, microstrength, and true density) of the derived needle coke. Therefore, the effects of the contents of β resin on the properties of needle coke were investigated thoroughly, and eight types of refined coal pitch (the f_a range from 0.9621 to 0.9725) with varied contents of β resin were employed as the precursors of needle coke. The techniques of proton nuclear magnetic resonance and gel permeation chromatography were utilized to determine the f_a and molecular weight of each refined coal pitch, respectively. Microstructures (optical microstructure and surface morphology) have been analyzed by polarizing microscopy and scanning electron microscopy, separately. X-ray diffraction, Raman spectra, and curve-fitting enabled the quantitative examination of the microcrystalline structure. What is more, the microstrength and true density of each needle coke have also been examined in this study. It was concluded that a β resin content of 13–16% in the refined coal pitch achieved the best results and was optimal for needle coke production.

中文翻译：

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煤沥青针状焦的制备与表征（第二部分）：β树脂在精煤沥青中的作用

精制的煤焦油沥青由于其优异的物理化学性能，被认为是生产针状焦的有前途的材料。公认的是，在延迟焦化过程中，精炼煤沥青的基本性能在影响所得针状焦的最终质量方面起着至关重要的作用。我们以往的研究表明，一个˚F_一个精煤沥青的0.95-0.98最佳，生产出的最高质量的针状焦。此外，我们发现精制沥青中的β树脂含量对衍生的针状焦的性能（微观结构，微观强度和真实密度）也很重要。因此，对针状焦的性质β树脂的含量的影响进行了深入调查，和八种类型的精制煤沥青的（所述˚F_一个从0.9621到0.9725的范围）与被用作针的前体β树脂的变化内容可乐。质子核磁共振和凝胶渗透色谱的技术被用来确定˚F_一个和每个精制煤沥青的分子量。显微结构（光学显微结构和表面形态）已分别通过偏光显微镜和扫描电子显微镜进行了分析。X射线衍射，拉曼光谱和曲线拟合使得能够对微晶结构进行定量检查。此外，本研究还检查了每个针状焦的微强度和真实密度。结论是，精炼煤沥青中的β树脂含量为13–16％达到了最佳效果，并且对于针状焦生产是最佳的。