煤的热塑性与其黏结性和结焦性之间关系及其对焦炭质量影响规律研究

Study on the relations between the thermoplasticity and caking and coking properties of coal and its effects on the quality of coke has a great significance for further understanding the mechanism of caking to coke, opening and reasonably utilizing the coking coal resources and improving the quality of coke. Coals with different ranks and their hydrothermal treated ones are thermal dissolved and catalytic thermal dissolved to produce thermal soluble fractions with different composition and structure. The dynamic viscoelasticity, caking and coking properties of thermal soluble fraction are measured and the structural characterization and oxygen groups' distribution analysis are carried out. Then the effects of composition and structure of coal on its thermoplasticity and the relations between the thermoplasticity and caking and coking properties of coal will be discovered. In order to understand the relation between the coal structure, composition and the mesophase translation properties of plastic material and the effect mechanism of optical microstructure formation of coke, the mesophase translation process of thermal soluble fraction is observed, and the optical microstructure, anistropic extent and combination interface of coke are investigated. Addition of thermal soluble fraction and model compounds in coal blends for coke-making, the quality of coke obtained is evaluated to relate the thermoplasticity of coal and the quality of coke obtained. Based on the results, the scientific question that is the effect law of thermoplasticity of coal on the quality of coke obtained is brought in light, and the key factors to affect the quality of coke in coal blending composition and structure are revealed. Then a new way for opening coking coal resources and improving the quality of coke is explored.

煤的热塑性与其黏结性和结焦性的关系及其对焦炭质量的影响规律这一科学问题研究，对于进一步认识煤的黏结成焦机理，扩大和合理利用炼焦煤资源，提高焦炭质量具有重要意义。本项目通过对不同变质程度的煤种及其水热处理煤的热溶和催化热溶等手段，制备具有不同组成与结构的热溶物，进行热溶物的黏弹性、黏结性和结焦性分析，并通过对热溶物结构和含氧官能团分析表征，揭示煤的组成结构对其热塑性的影响及其与黏结性和结焦性之间的关系。对热溶物的中间相转化过程以及焦炭的光学显微结构，光学各向异性程度和结合界面分析，揭示煤的组成、结构与所形成胶质体的中间相转化性质及其对焦炭的光学显微结构影响机理。通过添加热溶物以及模型化合物配煤炼焦，考察其对焦炭质量影响，从而将煤的热塑性与焦炭质量相关联，揭示煤的热塑性对焦炭质量影响规律这一科学问题，探明配合煤的组成与结构中影响焦炭质量的关键因素，为扩大炼焦煤源，提高焦炭质量探索一条新的途径。

本项目通过对褐煤、次烟煤热溶，得到不同组成与结构的热溶物，进行热溶物的黏弹性、黏结性和结焦性分析，并通过对热溶物结构和含氧官能团分析表征，同气、肥和焦煤等炼焦煤热溶物性能进行比较，揭示煤的组成结构对其热塑性的影响及其与黏结性和结焦性之间的关系。通过添加各种热溶物以及模型化合物配煤炼焦，考察其对焦炭质量影响，揭示煤的热塑性对焦炭质量影响规律这一科学问题。结果表明，神府次烟煤及肥煤热溶物按1:1配入标准无烟煤炭化后，同肥煤热溶物相同，神府次烟煤热溶物所得焦炭含有30-40%的各向异性组织。说明尽管神府次烟煤属不黏煤，但其热溶物在热解过程中能够形成胶质体，并通过中间相转化为光学各向异性组织，从而可以改善焦炭性能。神府煤热溶物的黏结指数超过一般的肥煤，具有较好的黏结性能，其配入炼焦煤后可以明显降低配合煤的软化温度，拓展热塑性。同肥煤热溶物一样，添加神府煤热溶物配煤炼焦后可以明显提高焦炭质量，较低温度得到的热溶物，其对焦炭质量改善更明显，这与其-OH含氧官能团的含量相一致。锡林郭勒褐煤热溶物均具有较好的黏结性能，其黏结指数GR.I超过一般的肥煤；热溶物的软化温度较低，在热解过程中能够形成较宽的塑性温度区间。添加5wt%锡林郭勒褐煤和焦煤热溶物替代等量的肥煤用于配煤炼焦，所得焦炭相对于不配热溶物的基准配煤焦炭反应后强度明显提升，质量明显提高，表明褐煤和焦煤热溶物其黏结性能和结焦性能优于肥煤。分别配入5%模型化合物萘、1-萘酚和蒽替代肥煤，相对于没有配入模型化合物的基础配煤所得基准焦，其反应后强度由基准焦的53.2%分别提高至63.9%、56.9%和58.2%，光学各向异性指数OTI也由基准焦的100.5分别提高至128.1、115.9和119，说明添加这几种具有2个芳环及以上的模型化合物均可以提高焦炭质量。但同样是具有2个芳环的萘酚，其对焦炭性能的改善效果远低于萘，表明萘酚中的酚羟基不利于对焦炭质量的改善，这与含氧官能团具有高缩合反应性有关。