Effect of multi parameter synergy on the upgrading characteristics of wide size moist coal

Through composite dry separation, effective precipitation and impurity removal can be achieved, improving the quality of raw coal. This paper mainly systematically analyzes the synergistic control mechanisms of airflow velocity, airflow transition layer height and control angle on the upgrading characteristics of moist coal. The results show that Zone I is a high airflow area, and when v = 2.12 m/s, it can effectively destroy the original static stable structure of low-density particles, increase the degree of freedom of particle accumulation volume, and achieve effective precipitation of particles. Zone II is a medium air volume area, and when v = 1.78 m/s, the high-density particle group in this area has the weakest obstruction effect on airflow, which can achieve efficient particle precipitation. Zone III is a low airflow area, where the dispersion of high-density particle groups increases at v = 1.36 m/s. The airflow can effectively act on the particles through the bed layer, reducing their surface water. When the height (H) of the gas transition layer is 49-52 mm and the regulatory perspective is 20–25, the distribution uniformity of the gas flow in the bed is the best. After separation and upgrading, the moist coal concentrate yield is 78.3%, ash content is 10.05%, as well as the possible deviation E value is 0.1 g/cm3.