A ball mill process design engineer was asked to calculate the work input required to grind the ore in a ball mill from 80% passing 1650m to 80% passing 60m. The Bond work index of the ore was found to be 15 kWh/t and the specific gravity of the ore is 5.7. Also determine the energy consumption in giga-joules after an 8-hour shift if the mill has a throughput of 2000 tph.