Discussion on reflectance measurement of vitrinite and type judging of mixed coal

YANG Ni

doi:10.3969/j.issn.1007-7677.2024.03.012

Abstract：Commercial mixed coal is a product formed by mixing different coal grades during the coking and blending process.Accurate determination of the vitrinite reflectance of commercial coal is crucial for identifying the original coal types of mixed coal,predicting coke quality,and optimizing coal blending technology.Based on the current coal rock testing standards in China,this paper explores the influence of factors such as coal petrographic analysis sample preparation and measurement points on the determination of vitrinite reflectance in mixed coal.Based on the current phenomenon in the determination and type determination of mixed coal reflectance,it is proposed that the grinding and polishing quality of fine coal has a significant impact on component identification and measurement re-sults,and the number of measurement points plays a decisive role in the statistical histogram of reflectance results and the determination of mixed coal type.The standard deviation of reflectance measurement is a key indicator for judging mixed coal.The determination of mixed coal type is mainly based on the standard deviation of measurement values and the number of notches.The average value of measurement values has no practical significance for industrial appli-cations.The advantage of reflectance histogram distribution is that it can intuitively reflect the original coal type and mixing degree of mixed coal.Accurate measurement of mixed coal vitrinite reflectance requires testing personnel of coal quality to have sufficient knowledge of coal petrology.It is recommended to incorporate the basic theory of coal petrology into the skill training system of inspectors,in order to improve the accuracy of mixed coal vitrinite reflec-tance testing and reduce the discrimination error of mixed coal types.