Experimental Investigation of Particle Size Alteration and the Selective Crushing Phenomenon of Gangue during the Jaw Crushing Process

Abstract

This study examines the particle size and distribution of the main chemical components of gangue during the crushing process. Coal mine gangue was chosen as the research object, and its particle size and chemical components at various crusher discharge settings were examined through screening, grinding, chemical composition testing, and other methods. The findings demonstrate that the characteristic particle size in the gangue particle size distribution model has a logarithmic upward trend as the width of the discharge port increases. In contrast, the uniformity index has shown an exponential downward trend. The analysis of the distribution rate and enrichment ratio of the main chemical components of the gangue at different widths of the discharge port shows that the gangue exhibits obvious selective crushing during the crushing process. The distribution rate of each component is affected by the size of the screen aperture to various extents. As the discharge port width increases, the elements of CaO and MgO are enriched in the coarse-grained products, while those containing Fe2O3 are enriched from fine-grained to coarse-grained. Gangue particles containing Al2O3, SiO2, and C are enriched in the fine-grained product. In addition, by analyzing the alterations in the main chemical components of gangue at different particle size intervals, it was found that the amount of each component first rises and then falls, and the trend of enrichment ratio to particle size follows an exponential pattern. The research results have significance for guiding the selection of resource utilization methods of gangue with different particle sizes after crushing.

Evolution Characteristics of Void in the Caving Zone Using Fiber Optic Sensing

“…The areas near the coal mining face experience lower stress, resulting in loose rock distribution and larger inter-rock voids, making them ideal for effective slurry filling. However, as the distance from the goaf and mining face increases, the load-bearing capacity of the collapsed rock mass gradually grows, leading to the compaction of loosely piled rocks and a reduction in inter-rock voids, thereby diminishing the effectiveness of slurry filling [ 5 , 6 , 7 ]. Therefore, understanding the evolving characteristics of voids in the collapsed rock mass behind the coal mining face is of paramount importance for successful slurry filling.…”

Research and engineering practice on space characteristics of gangue slurry filling

“…The issue of gangue emissions accompanying coal production is one of the key factors currently hindering the green and efficient development of the coal industry [1,2]. According to statistics, the accumulated amount of coal gangue in China has exceeded 6 billion tons, forming over 1,700 gangue mountains covering an area of more than 200,000 acres, with an annual emission rate increasing to approximately 700 million tons [3].…”

“…To address the environmental issues and safety hazards caused by surface accumulation of gangue, research on comprehensive utilization and backfilling mining of coal gangue has been conducted both domestically and internationally, and corresponding achievements have been made [6,7]. However, the large volume of gangue and the relatively low comprehensive utilization rate [8][9][10], as well as the high cost and limitations of traditional backfilling mining techniques, such as the mutual influence of mining and backfilling processes and the impact of backfilling on working face productivity [11][12][13], make existing gangue utilization methods and approaches inadequate for efficient, green, and large-scale disposal of coal gangue.…”

Research and engineering practice on space characteristics of gangue slurry filling

“…To address the environmental issues and safety hazards caused by surface accumulation of gangue, research on comprehensive utilization and backfilling mining of coal gangue has been conducted both domestically and internationally, and corresponding achievements have been made 6 , 7 . However, the large volume of gangue and the relatively low comprehensive utilization rate 8 – 10 , as well as the high cost and limitations of traditional backfilling mining techniques, such as the mutual influence of mining and backfilling processes and the impact of backfilling on working face productivity 11 – 13 , make existing gangue utilization methods and approaches inadequate for efficient, green, and large-scale disposal of coal gangue.…”