Development of a Segregation Blasting Method to Reduce Ore Loss and Dilution in Open Pit Mines

ABSTRACT A segregation blasting method was developed and implemented to improve the segregation of materials at the boundary of ore and waste, which can reduce ore loss and dilution in open pit mines. Through theoretical and simulation analyses, the design principle and blasting parameters for the segregation blasting were determined. The delay time of 100 ms was used to produce a separation zone at the boundary of ore and waste. The 3D laser scanning technology was used to evaluate the blasting performance. After optimization by experimental blasts, delay time of 17 ms, 64 ms and 100 ms was changed to 9 ms, 25 ms and 65 ms, respectively, and the loading efficiency increased 3.1% ~ 17.6%. Field studies indicated that the percentage decrease in ore loss was 2.63~5.3% and the decrease in dilution was about 2% by segregation blasting. Analyses and experiments indicated the segregation blasting method has the advantages of more proper fragmentation and muckpile shape, shorter loading time, less ore loss and dilution.