The influence of the synergistic effect of airflow and vibration in compound dry separation bed on upgrading of 6–0 mm fine-grained low-grade high-sulfur lignite

• Published in: Fuel (Guildford) 2022-12, Vol.330, p.125590, Article 125590
• Main Authors: Yu, Xiaodong, Luo, Zhenfu
• Format: Article
• Language: English
• Subjects: Airflow and vibration synergy; Compound dry separation; Desulfurization and ash reduction; Low-grade high-sulfur lignite; Particle impact force
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2022.125590

[Display omitted] •A new compound dry beneficiation technology for 6–0 mm lignite was proposed.•Innovative study of airflow and vibration synergy.•The dominant action stage of airflow and vibration conditions was determined.•The spatial distribution layer of the materials on the bed area was determined. Coal is the important support to guarantee the national energy security system. China is the largest coal producer and consumer country and the lignite reserves are abundant. In recent years, as the high-quality coal resources decrease and the difficulty in mining increases, low-grade lignite resource has been the important component of China’s energy production and supply. Promoting the clean and efficient utilization of low-grade lignite is an important approach to realize the goal of carbon peak and carbon neutrality. In this paper, compound dry separation bed was used for the desulfurization and ash reduction of fine-grained low-grade high-sulfur lignite. The synergistic effect of airflow and vibration on particle force characteristics was emphatically investigated and the leading action stage under different airflow and vibration conditions was determined. The spatial migration acceleration variation rule and spatial migration trajectory of particles in different areas under the synergistic effect of airflow and vibration were systematically analyzed. Meanwhile, the spatial distribution characteristics of sulfur content of fine-grained low-grade high-sulfur lignite on the compound dry separation bed and the segregation rule of particles on the different areas along the bed transverse direction were explored, and the spatial distribution layer of the materials on the bed area was determined. The experimental results demonstrate that under condition of Γ = 10.14, when the gas velocity U = 0.125 m/s, vibration plays a leading role in the particle migration on the bed surface; when the gas velocity U = 0.148 m/s, vibration plays a leading role and the airflow plays a surrounding role; when the gas velocity U = 0.229 m/s, the synergistic effect of airflow and vibration dominates in the particle migration. The motion trajectories of particles in each cross section are all oval shape. The variation of acceleration amplitude along OX-axis determines the transverse migration trajectory of particles; the variation of acceleration amplitude along OY-axis determines the peak force characteristics of particles; the variation of acceleration amplitude along OZ-axis