Dust control in underground coal mines has long been of great concern to mine operators, and the use of an auxiliary ventilation system is essential to address dust pollution. The present study focuses on analyzing gas -solid two-phase flow in a typical coal roadway with a fully mechanized heading face in the presence of an auxiliary ventilation system with an air curtain. The two-phase flow was simulated by the Euler-Lagrange method. The dust particles were simulated via the discrete phase model (DPM) based on certain sample particles in the form of parcels. To control dust more effectively, the air curtain generator was optimized based on a recently proposed structure. It was found that the air curtain and the improved form have obvious effects on the air flow field, the dust distribution and the amount of particulate matter (PM2.5) in the front part of the roadway (within approximately 15 m of the heading face). PM2.5 around the driver is substantially reduced after the improvement but is limited when the initial supply air velocity is increased. Selected simulation results were verified by relative field measurements. The results obtained in this study provide useful information on auxiliary ventilation design for use in mining activities. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.