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.