Evaluation of coal component liberation upon impact breakage by MLA. (15th December 2019)

• Record Type: Journal Article
• Authors: Fu, Yanhong; Li, Zhen; Zhou, Anning; Xiong, Shanxin; Yang, Chao
• Is Part Of: Fuel. Volume 258(2019)
• Publication Date: 2019-12-15
• Subjects: Mineral liberation analysis -- Mechanical impact breakage -- Liberation mechanism -- Coal components; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2019.116136
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: The coal component liberation mechanisms upon impact breakage was analyzed by MLA. Particle comminution quantified by the changes of slope ECD-CMR curve. The liberation factor was adopted to quantified mineral liberation condition. Changes in mineral boundary and mineral area corresponding to different fractures. Abstract: To elucidate the coal component liberation mechanisms upon typical impact breakage, the coal was selected from the Shangwan mine in China. Thereafter, mineral liberation analysis was adopted as the main method for investigating phase interface characteristics, classification characteristics of the various classes of comminuted products, and changes in the mineral area and length gradients upon mechanical impact breakage. The results indicate that the grain sizes of the comminuted products decreased in the following order: slag product >classifier product >bag product. Moreover, the disseminated grain size, dissemination mode, and original cleavages had a direct influence on the recovery rate of the completely liberated phase. The coal, which formed the main component of the samples, exhibited the highest cumulative mass recovery (CMR) in classified products and was most easily liberated. Furthermore, the kaolinite-bearing coal and pyrite were moderately liberated, the quartz and kaolinite were difficult to liberate, and the illite was extremely difficult to liberate. Under mechanical impact breakage, intragranular and intergranular fractures mainly occurred in particles, with the changes in the mineral boundary and mineral area corresponding to varying fracture modes. To a certain extent, the particle comminution could be quantified by the changes in the slope of the equivalent circle diameter–- CMR curve. It was determined that the main cause of the increased liberation degree is the generation of the completely liberated phase of the component of interest. Furthermore, by adopting the liberation factor for quantification of the mineral liberation, the calculation model for coal component liberation was obtained.