Study on the fire-extinguishing technology for three types of blasting borehole in open-pit mine burning area

It’s difficult to cool the high temperatureblasting borehole before stripping the overlying strata in the open-pit mine fire zone.According to the location distribution of blasting boreholes relative to the fire zone,the blasting boreholes can be classifiedas three types:blasting boreholes above the fire zone,blasting boreholes through the fire zone and blasting boreholes near the fire zone.Based on the different blasting boreholesdistribution,the appropriate fire-extinguishing method is applied.The comprehensive fire-extinguishing scheme is based on three phase foam,supplemented by water injection and grouting.Compared with water injection and grouting,the comprehensive fire-extinguishing technology control the fire zone efficiently.A firing zone of 150,000m² in Donglutian was completely controlled and the safety production on schedule was ensured.