Iron Ore Company of Ontario “A3 Written Assignment”
December 12, 2011
Presented to: Dr. James Mason
Presented by: Ahmed Omar Afify
Student ID: 200-305-478
* To minimize total waiting time and stockpile re-handling costs (Keep operations costs as low as possible). * To improve productivity process and decreasing idle time of machines and labor. -------------------------------------------------
* Iron Ore Company of Ontario is working in the business field of processing iron ore. * Production was scheduled on a year-round, 24 hour-per-day basis to produce over 46 million tonnes of crude ore per year, of which 21 million tonnes are high grade concentrate. * To achieve this capacity, a concentrator was built with input capacity of 1760 cubic meter of crude ore per hour, i.e. concentrator was used at full capacity at all times. * Production Process
* Large drills cutting 12-metre holes into solid rock. * These holes are then filled with explosives.
* Electric Shovels start to load the trucks.
* Trucks carry waste material to waste dump outside the mine, while ore was carried to the crushers. * The ore enters the crushers, where large rocks were reduced in size. * The crushed ore passed by conveyor to the concentrator where it was further crushed into waste tailings and 66% iron concentrate. * The concentrate product was finally loaded on a ship and exported to Europe and North America. * Shovels
* Shovels load an average of 480 cubic meters per hour per unit. * 7 Shovels were available per shift in Ore Zone, while the 8th Shovel was located at crude-ore stockpile “for less usage”. * Remaining Shovels were undergoing maintenance.
* Tractors clear loose rock from the loading area while shovel was waiting for trucks, so that loading area becomes smooth to reduce truck-tire wear. * Tractor works one hour for each hour worked by stockpile shovel, plus 1.5 minutes per load dumped on the stockpile. * Trucks
* Trucks transfer the ore from the shovel in the mine to the crushers, then return to transfer the other load back to the crushers, and also transfer the waste to waste dumps. * 4 trucks were assigned to each shovel; and the truck assigned to shovel working in ore travels about 1.5 kilometers between shovel loading area and the crushers. * The Crushers
* There were 2 crushers; together they were able to handle a maximum of 9420 tonnes per hour. * Two trucks could dump simultaneously into each crusher, with an average time of 1.7 min (0.028 hr) to dump. * There was considerable wear and tear of machinery in crushers due to weight and hardness of rocks. Thus, one crusher was almost closed during the day-shift, reducing the intake capacity of crushers from 9420 to 4710 tonnes per hour. * The 2 crushers remained working during afternoon and night shifts, but for the day shift, one crusher is working and the other is under maintenance. * The Stockpile
* Stockpile stage was created about 120 meters from the crushers, so that loaded ore trucks dump the ore in the stockpile rather than returning loaded to the mine when both crushers are down. * About 15 minutes of production was lost each time a shovel changed location from ore zone to waste zone. * The cost of ore reaching the stockpile was the same as the cost of ore entering the crushers; as the time required for a loaded truck to come from shovel in mine, turn and dump on the stockpile was effectively the same as the time needed to carry ore to one of crushers, turn, and dump. * Any ore dumped on stockpile should ultimately be moved to the crushers, provided that trucks only...