Behind the scenes as Kumba just keeps on truckin’
The drivers of monster trucks that can haul 327 tons of rock at a time push themselves hard
Kumba Iron Ore is increasingly using technology to improve efficiencies and costs, but at the heart of its operations are people who are putting in enormous efforts during the fundamental tasks of loading and hauling rock – the biggest cost items at the company’s flagship Sishen mine in the Northern Cape.
Loading and hauling make up two thirds of the cost of the iron ore coming from South Africa’s largest iron ore miner. Since the iron ore price collapsed in 2015, Kumba gave that aspect of its operation close attention, says Mapi Mobwano, the general manager of Sishen.
Despite a drop in the size of the truck fleet to 98 machines from 136 in the first half of 2016, the mine’s daily tonnage moved shot up 62% to 613,000 tons since then, with a more highly motivated workforce, a better mine design, changed shift systems and improved blasting, he says.The drivers of monster trucks that can haul 327 tons of rock at a time push themselves hard, keeping Anglo American subsidiary Kumba steadily moored in fifth spot in the global league of seaborne iron ore exporters, but their shift system demands working hours that would leave most people numb and bored.
In a 12-hour shift, there is a 20-minute lunch break followed by a 30-minute discretionary break towards the end of the shift, but some drivers opt not to take either, pushing right through with their eye on a quarterly bonus that can triple their small salary for the period. Truck drivers earn a basic wage of between R12,000 and R15,000 a month.
“This job is not for everyone,” says a driver with six years of experience as he steers a truck so large a series of steep ladders built onto the front of the engine is needed to reach the small airconditioned cab perched high above the ground. “Fatigue is the big thing.”
The truck, which has surprisingly soft suspension and rolls like an old scow in a storm, inducing instant seasickness in those unfamiliar with the ride, is combined with an enormous digger that takes three scoops to fill the truck.With the use of an onboard computer that calculates loads and a running tonnage total for the shift, the driver relies on an electronic map of the 60km² mine to find loading and tipping points sent to him from a central office, a huge advance on six years ago when drivers relied on memory to traverse a baffling array of roads.
The Sishen mining team will visit the vast openpit Jwaneng diamond mine in Botswana to see how their peers in the Anglo stable are running their truck fleet more efficiently than at Sishen, with a fraction of the time spent idling engines, wasting expensive diesel, for example.With a truck burning through 6,000 litres of fuel in a 24-hour cycle and R500,000 tyres that last about 8,000 hours, it’s obvious why this is an area attracting special attention from Kumba’s management at the 31 million tons a year Sishen mine and the 13 million tons a year Kolomela mine.
While Kumba is well behind its peers like Rio Tinto, which has autonomous trucks and trains operating at its enormous Australian iron ore mines, it has started a three-phase approach to introducing as much technology as possible to rein in costs, boost productivity and extract the maximum value from SA’s largest iron ore operation.
The first fully autonomous pieces of equipment at Kumba are drills used to sink blasting holes. The drills are monitored by specialists in a building elsewhere on the mine, while the truck drivers have a fully digital cab, dropping queuing times and increasing the average travelling speed. The processing plants have been automated, giving a 6.5% improvement in throughput and an 83% improvement in stability, says Glen McGavigan, head of technology at Kumba.