The spatial diffusion rule and pollution region of disorganized dust in the excavation roadway at different roadheader cutting positions

The roadheader cutting process generates massive disorganized dust in the excavation roadway. The cutting azimuth has a remarkable effect on the dust diffusion. Nine representative positions are performed to evaluate the dust spatial characteristics. The large vortex with pressure lower than −5.0 Pa entrains massive dusts in the forepart roadway. The high-concentration dust shows an asymmetry linear decrease distribution in the horizontal. The minimum velocity migration drives the high-concentration area to move with the cutting azimuth change. The middle position makes a minimum stabilization time at 45 s, along with the smallest dust area and wrap volume. The maximum concentration gap reaches 168.1 mg/m3 at the driver. As the cutterhead moves upward, the dust occurrence time delays and the concentration peak/valley number extends by twice. The pollution regions obtained at the variational cutting azimuths provides ctitical guidance for implementing the dynamic dust-proof measures and realizing a sustainable clean production. [Display omitted] •Nine representative cutting positions are conducted to evaluate the dust characteristics in the personnel operation area.•The dust concentrationn shows an asymmetry linear decrease distribution in the horizontal direction.•The minimum wind velocity zone migrates counterclockwise.•There are two concentration peaks at the driver in the upper and lower.•The middle tunneling azimuth lies in the lowest dust pollution level.