2031 X80 = 80% of the blasted rock mass passes through that screen size (cm) ;1< = explosive energy per unit weight (%) Cc = loading cost ($/t) $c = hourly loading operation cost ($/h) Uc= loading operational utilization (%) =D = shovel payload (t) a = coefficient as a function of lithology, operator, and equipment operating conditions b, c = operational coefficients of the shovel rotation process > = rotaion angle in shovel operation (◦) ?D, = loading dump time (min) Ct = haulage cost ($/t) $t = hourly cost of the haulage operation ($/h) p = number of passes tv = round trip travel time (min) td = hauling dump time (min) te = waiting time and other maneuvers (min) Ut = haulage operational utilization (%) Lt = average haulage capacity (t) Cbp = unit cost in primary crushing ($/t) 1) = Bond work index (kWh/t) P80= size at which 80% of the crusher product passes (μm) X80 = size at which 80% of the ore feed to the crusher passes (@A) $e = electric energy cost ($/kWh) $bp = human costs, materials, maintenance and others ($/h) f = ore fraction classified to primary crushing Pbp = ore fed to primary crusher (t/h) c = calibration factor based on practical mine data ($/t) Figure 1 – Cost-minimization model for the blasting-to-primary-crushing chain In this paper, we present the application carried out in 2024 and 2025 at the Brucutu mine, which is one of Vale’s large-scale automated iron mines.
RkJQdWJsaXNoZXIy MTM0Mzk2