Specific properties and combustion characteristics of natural coke from adjacent areas of Jiangsu, Shandong, Henan and Anhui provinces

It is particularly important to improve resource utilization efficiency against the background of carbon peak and carbon neutrality, but the natural coke has not been paid enough attention for a long time. The natural coke is abundant in China and is often found in the mining of coal mines in neighboring areas of Shandong, Henan and Anhui provinces. Due to the intrusion of magmatic rock, the original coal seam is baked and transformed into natural coke. In this study, samples of natural coke from various areas were collected to study its macroscopic and microscopic characteristics. The industrial analysis, geochemical parameters, spontaneous combustion tendency and coke dust explosive were studied. At the same time, typical samples were selected to analyze the combustion characteristics by American TA2100 thermal analyzer. The results show that the macroscopic physical properties and maceral properties of natural coke are obviously different from those of coal. On the whole, there is no obvious boundary about the analysis indexes of natural coke and anthracite. The index of volatile yield and C/H values for natural coke and the residual coal in the same place is significantly decreased by the former, and greatly increased by the latter. The metamorphic degree of natural coke is generally reached or higher than that of anthracite, and it is not easy to spontaneous combustion with its coke dust non-explosive. The analysis of combustion characteristics shows that the natural coke sample has strong reactivity. Furthermore, the utilization direction of natural coke was discussed according to its characteristics, and there is value or potential in the production of briquette, ammonia synthesis, carbon materials, cement production and CO₂ geological storage.