Boliden Aitik mine: Doubling production with new facilities, expanded site and larger trucks
Despite operating in some of the world’s toughest conditions, expansion has been a regular occurrence at Boliden Aitik copper mine. Already one of Europe’s largest copper mines, in 2010 Aitik built new facilities and launched an expansion program that is set to double its production by 2014.
As the mine’s production increases, so must the size of its haulage fleet. Aitik started with 65-tonne (72-ton) trucks, upgraded to 100-tonne (110-ton) models, then to 170-tonne (152-ton) trucks. In 1988, Boliden was one of the first companies to purchase the new 181-tonne (200-ton) Cat® 789 truck, purchasing four units and adding two more in following years. In 1993, Boliden began purchasing 227-tonne (250-ton) Cat 793B trucks, continuing with the C and D series trucks until building a fleet of 22 trucks. Today, Aitik is the first mine in the world to put into production the new Cat 795F AC, a 313-tonne (345-ton) electric drive truck that joins the 793s to boost annual production to 36 million tonnes (39.68 million tons).
“This mine is always expanding,” says John Pettigrew, a Caterpillar mining manager who worked on the sale of the new fleet of 795s. “They’ve gone from one of our smaller mining trucks to one step away from the largest. And they may not stop there. Their new workshop is set up to service the 363-tonne (400-ton) 797 if they decide to expand yet again in the years ahead.”
Efficiently producing copper
Boliden is a leading European metals company engaged in exploration, mining, smelting and recycling. Boliden’s main metals are zinc and copper. The Aitik open pit mine is Boliden’s biggest mine, producing copper ore that also contains gold and silver. The metal grades are low but are compensated for by high levels of productivity and efficient concentration processes. Aitik employs about 580 people and is the largest private employer in the municipality of Gällivare.
The mining production method is drill and blast. Material is loaded onto haul trucks and transported to two crushers, one inside the pit itself and one at surface level to reduce truck mileage. From there the rock is carried on a 7.0-kilometer (4.35-mile) belt conveyor system, first to an intermediate stockpile and then to a main ore storage building near the mine’s concentrator plant. Grinding and flotation technology separates out the copper concentrate, which is transported by train — roughly 500 tonnes (551 tons) per day — to the Ronnskär copper smelter at Skellefteå, 360 kilometers (224 miles) away.
Large amounts of waste rock must be removed in order to produce the ore. It’s estimated that altogether over 480 million tonnes (529 million tons) of waste rock have been removed. That waste now finds use as road reinforcement and as ballast in concrete manufacture.
The successive ramping up of production that began in 2010 will continue until the mine reaches full capacity. The expansion will allow the mine to extract additional ore and this, coupled with positive exploration results, will extend Aitik’s lifespan from 2016 to 2030.
The ore reserve is estimated at 733 million tonnes (808 million tons). This total breaks down into 504 million tonnes (556 million tons) of proven ore reserves and 229 million tonnes (252 million tons) of probable ore reserves. Measured and indicated mineral resources amount to an additional 1 553 million tonnes (1,712 million tons).
Taking advantage of demand
As world demand for copper increases, Boliden is eager to deliver as quickly as possible to take advantage of the booming commodities market. That makes it even more important to mine effectively and efficiently.
Increasing haulage capacity
One way Aitik is increasing productivity is by investing in a fleet of larger trucks.
“They knew that bigger trucks would be key to increasing their production,” says Pettigrew. “They already operated the 793, and the next size up—the Cat 797 — was just too big. But their timing was perfect, because Caterpillar was just getting ready to launch the 795, a new size class for us that is well-placed to match a wide range of mining shovels.”
Aitik’s loading fleet consists of electric rope shovels that load the 795F in three to four passes.
While payload was the main consideration that led Aitik to the 795, the truck’s ability to operate in the challenging environment and weather conditions was another deciding factor.
Aitik is located 100 kilometers (62 miles) north of the Arctic Circle. Production continues 24 hours a day in temperatures that can drop to minus 40 degrees Celsius (minus 40 degrees Fahrenheit) in winter and rise to 30 degrees Celsius (86 degrees Fahrenheit) in summer. Trucks have to operate on haul roads whose frozen surface melts in the spring, making hauling on slopes of 10 percent or more a challenging proposition.
The site has been happy with the performance of its mechanical drive 793 trucks in these conditions, and found that the 795 can offer the same, or even improved, performance thanks to its braking system, which allows operators to brake electrically, hydraulically, or as a combination of both.
“The mine has operated electric drive trucks in the past,” says Pettigrew.“But they found that they were challenging to operate in the snow and ice — a pretty regular occurrence in this region.”
The 795s have the same braking ability as the Cat 793. The truck’s four-corner blended braking and retarding — using oil immersed and cooled disc brakes as well as electrical retarding — is designed to enhance safety and operator confidence.
“The unique braking unit can use the brake force in the hydraulic brakes on the front wheels, giving a retarder brake on all four wheels,” says Lars Almqvist of Cat dealer Pon Equipment. “This is completely unique to Caterpillar, and in the rough winter climate of Aitik, this quality certainly adds a great benefit. Especially when you’re driving with 313 tonnes (345 tons) on board.”
Productivity is also enhanced by the 795’s Cat C175 diesel engine. The C175 meets US EPA Tier 2 / Level II EU emissions standards, yet it delivers 2 535 kilowatts (3,400 horsepower) of power.
Supporting a new fleet
Pon Equipment has been supporting the mine’s Cat equipment for decades. In addition to its haulage fleets—two 789 and 23 793 mining trucks — Aitik also operates all Cat support equipment. Products on site include two D10 track-type tractors, three 16H motor graders, seven 980 wheel loaders and two 994 wheel loaders. The site is also considering additional services from Pon, including leveraging the Cat MineStar™ System, a suite of mining technology products.
The purchase of the 795 fleet required a significant investment from Boliden, the Cat dealer and Caterpillar itself. The three parties have a long partnership and all were committed to supporting this new fleet in the best way possible.
The new maintenance shop Boliden built as part of the expansion, for example, was specifically designed to support the new truck fleet. The building is 7 500 square meters (80,729 square feet), and 25 meters (82 feet) from floor to ceiling. It features 12 large doors, 10 workshop areas, plus a washing area and a tire shop.
The dealership also had to prepare for the new fleet. “Moving from supporting the 793 to also supporting the 795 is not an easy move for the dealer,” says Griffin Reome, a Caterpillar technical representative responsible for Aitik. “This required a significant investment in an updated inventory to make sure they had the right parts and components on site to support the customer.”
Pon also had to expand its workforce for the new fleet. “The dealer needed more people, and not just mechanics,” says Pettigrew. “They needed another person in their parts warehouse and someone to manage the maintenance and repair contract.” Dealer personnel also received training in repair and maintenance specific to the 795.
As part of its partnership with customers, Caterpillar provides regular training and support in a number of areas. In February, for example, training was provided jointly by the Caterpillar Global Mining organization, a service operations team from the Caterpillar Europe, Africa and Middle East region, and Pon Equipment. Experts visited the site to do in-depth training on the importance of controlling contamination.
Michael Loyer, a Caterpillar service operations consultant, was responsible for bringing the team to the site. A mixture of Boliden employees and technicians from Pon Equipment participated. The goal was not only to protect the site’s equipment, but also to help the site save money.
“You have to ask yourself how often you change hydraulic oil filters, transmission fluid, axle oil,” Loyer says.“If you could safely extend the change intervals, what would be the effect on running and maintenance costs? And what if you could extend the life of hydraulic components, transmissions, final drives and differentials, and fuel injectors? What could you save? By how much could you improve operating efficiency? The single greatest opportunity for increasing component life and lowering operating costs is to effectively manage fluid cleanliness. And that’s what our training session was about.”
Contamination control is important for every site and every machine. At Boliden, having people well-trained in contamination control took on greater importance as the site expanded operations.
“With production at the mine increasing, we have growing demands placed on us, so we need well-trained people,” says workshop supervisor Mats Petterssen. “We need to know more, to be able to work more effectively in supporting the company’s drive for cost efficiency. This training makes a significant difference.”
Loyer agrees. “Good training always pays,” he says. “That’s why it’s considered so important by everyone at Caterpillar. But here the payback could be truly impressive. That’s why we’re here, to support Boliden’s drive for maximum efficiency.”
Evaluating the fleet
Both mechanics and truck operators received specific training for the 795s. Unlike many sites, where operators are trained for specific machines, all Aitik operators are trained to operate both the 793 and 795 trucks. The biggest adjustment, says Reome, is getting used to the size.
The first 795 has been operating at Aitik since February. A second came on board in March and two more of the 11 total in the fleet began production in June.
Operating hours so far total 2,700 for the first truck and 2,100 for the second to be put into production. The feedback has been positive, says Reome.
“There have been a few growing pains, but the operators really seem to enjoy them — especially the new operator station” he says. “The difference in the operator environment is night and day when compared to previous trucks. They’re ergonomically designed and more user-friendly. The technologies, like the VIMS screen, are more intuitive, which makes them easier to use and informs the operator of conditions on the truck.”