Laboratory results of foam application testing for longwall shield dust control in a simulated environment

Abstract There were 37 longwall faces operating in mines the United States 2019. The average panel width for these longwalls was approximately 368.5 m (1209 ft). This translates to a range of 170–240 shields per longwall, depending upon shield. movement is significant contributor respirable dust overexposures operators. Foam expected have potential reduce this shield generation. foam applied area on roof between coal face and tip after shearer passes. In study, simulator used test three agents their ability control from movements. Results showed that at low-velocity ventilation (≈ 3.0 m/s (600 fpm)) all able produce reduction levels least 45%. At high-velocity 5.1 (1000 fpm)), reductions lower more variable, ranging being undeterminable one agent having 46%–63% other two agents, with instance an increase concentration. Overall, use can provide control. Important factors are coverage remain extended time periods.