High-temperature coal tar pitch is often used to produce high-quality needle coke. Its basic properties [such as f_a value, β resin, and quinoline insoluble (QI) content] significantly affect the quality of the resulting needle coke. Refined pitch with f_a and β-resin values in the 0.95–0.98 and 13–16% ranges, respectively, is considered an excellent raw material for this purpose. The influence of QI content on the characteristics of coal-based needle coke is still not fully clarified in the literature. To analyze how QI content affects coal-based needle coke properties, this work used 10 different kinds of coal tar pitch (refined from the same source) with different QI contents for the needle coke production. We thoroughly analyzed optical microstructure and crystalline sizes, surface morphology and microstrength, true density, and coefficient of thermal expansion (CTE) of the resulting products. The high-temperature coal tar pitch with the QI content of <0.8% was a preferable raw material to obtain superior needle coke; it possessed higher density and microstrength, lower CTE, and graphitized more easily than cokes with other parameters.

中文翻译：

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煤沥青基针状焦的制备和表征（第三部分）：不溶于煤焦油沥青的喹啉的影响

高温煤焦油沥青通常用于生产高质量的针状焦。它的基本特性（例如f _a值，β树脂和喹啉不溶物（QI）含量）显着影响所得针状焦的质量。精制音高为f _aβ-树脂值和β-树脂值分别在0.95-0.98和13-16％范围内，被认为是用于此目的的优良原材料。QI含量对煤基针状焦特性的影响尚未在文献中充分阐明。为了分析QI含量如何影响煤基针状焦性能，这项工作使用了10种不同QI含量的煤焦油沥青（从同一来源精制）来生产针状焦。我们彻底分析了所得产品的光学微结构和晶体尺寸，表面形态和微强度，真实密度和热膨胀系数（CTE）。QI含量<0.8％的高温煤焦油沥青是获得优质针状焦的理想原料；它具有较高的密度和微强度，较低的CTE，