A sequence of hot briquetting and carbonization (HBC) is a promising technology for the production of coke with a high mechanical strength from lignite, but factors affecting the coke strength have not yet been fully understood. The HBC cokes prepared from 12 lignites in this study showed diverse tensile strength (e.g., from 0.2 to 31.2 MPa in the preparation at 200 °C and 112 MPa for hot briquetting and 1000 °C for carbonization), and the coke strengths could not be explained by differences in commonly used structural properties of the parent lignites, such as elemental composition and contents of volatile matter/fixed carbon and ash. In this study, two methods were proposed for correlating the coke strength with the lignite properties, which employed the chemical structure analyzed by solid-state ¹³C nuclear magnetic resonance or the volumetric shrinkage during carbonization. A stronger coke was obtained from lignite that contained more aliphatic carbons (less aromatic carbons) or shrank more considerably. These characteristics contributed to intensified compaction of lignite in the briquetting and suppression of the formation of large pores, which are a cause of coke fracture. Two empirical equations, predicting the coke strength from the parameters of lignite properties, were established to be criteria for selection of lignite as HBC coke feedstock, although further investigation with more experimental data would be necessary for the validation.

中文翻译：

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热压块和碳化将褐煤转化为高强度焦炭的特性

一系列的热压块和碳化（HBC）技术是一种有前景的技术，用于由褐煤生产具有高机械强度的焦炭，但是尚未完全了解影响焦炭强度的因素。在这项研究中，由12种褐煤制得的HBC焦炭显示出不同的抗张强度（例如，在200°C和112 MPa的热压块和1000°C的碳化中，其抗张强度为0.2至31.2 MPa），不能达到可以通过母体褐煤的常用结构特性（例如元素组成和挥发物/固定碳和灰分的含量）的差异来解释。在这项研究中，提出了两种将焦炭强度与褐煤特性关联的方法，它们采用了固态¹³分析的化学结构。C核磁共振或碳化过程中的体积收缩。从褐煤中获得了更强的焦炭，褐煤含有更多的脂肪族碳（较少的芳香族碳）或收缩得更多。这些特性有助于褐煤在团块化中的增强压实并抑制大孔的形成，大孔的形成是焦炭破裂的原因。建立了两个根据褐煤特性参数预测焦炭强度的经验方程，作为选择褐煤作为HBC焦炭原料的标准，尽管需要更多的实验数据进行进一步的研究以进行验证。