Located at 3,200 m above sea level in the Atacama Desert in northern Chile, the Escondida mine currently produces more than 1.1 Mt/y of copper. In 2015, the massive open pit mine also saw byproduct output of some 88,000 oz of gold and 4.8 Moz of silver.
In 2012, the mine started construction of two major expansions: the Organic Growth Project 1 (OGP1) and the Oxide Leach Area Project (OLAP).
Commissioned in 2015, the OGP1 allows the mine to access higher grade ore and includes a new 152,000 t/d processing plant. The project also uses four overland conveyors driven by 5 x 5 MW direct drives.
The entire four-flight direct drive conveyor system spans 10,632 m in length with the largest flight being 3,942 m long. At the time, this was the largest gearless drive conveyor in the world. The 1,800 mm wide belt conveyors, travelling at 6.4 m/s, move copper ore at a rate of 12,550 t/h. The high altitude conveyors operate in a wide range of extreme temperatures from -10˚C to +40˚C.
Svendborg Brakes worked closely with the conveyor OEM to design a complete intelligent braking solution to meet the challenging requirements for the four-flight gearless conveyor system. Tillman Speer, International Sales Manager at Svendborg Brakes, explained, “Due to the direct drive set up of these OGP1 conveyors, the required braking torque was extremely high.”
Groupings of two or six Model BSFB 650 spring-applied, hydraulically-released, dual-spring caliper brakes, acting on large 2.7 m diameter steel brake discs, serve as on/off holding brakes at the head and tail of the various conveyor flights.
“Two popular Svendborg Brakes SOBO controllers, paired with custom SOBO hydraulic power units, were installed in one of the center conveyor sections to meet additional safety requirements,” said Speer. “The redundant systems are identical and each is capable of stopping the conveyor by itself in case of an emergency.”
The OLAP, commissioned in 2014, features a robust leaching pad combined with three downhill overland conveyors with a total elevation drop of 207 m.
The entire three-flight conveyor system spans 4,778 m in length with the largest flight being 2,740 m long. These 1,524 mm wide belt conveyors, travelling at 4 m/s, move copper ore at a rate of 4,125 t/h.
Svendborg Brakes supplied braking systems provide emergency stopping and parking for 4 x 450 kW drives. Each system included a pair of model BSFK 535 spring-applied, hydraulically-released, dual-spring caliper brakes, a SOBO controller and a custom SOBO hydraulic power unit (HPU).
According to Speer, “The most important Svendborg Brakes criteria for the OLAP conveyor system was to provide safe and reliable braking and parking in emergency situations, while not affecting normal operation.”
Svendborg Brake’s unique soft braking control (SOBO) provides a range of safety and durability benefits in heavy industrial applications including mining. Deceleration and the stopping of heavy conveyor loads is critical, and controlled braking is essential for a significant reduction of torque peaks, preventing damage to the belt and mechanical components.
Specialized hydraulic power units, manufactured in-house by Svendborg Brakes, are engineered to meet any mining requirement. In order to minimize downtime, the units are equipped to monitor oil level and temperature, motor and pump function, and operational pressure.
Svendborg Brakes provided complete single-source braking solutions and support from concept and design through packaging and commissioning.
“We were very responsive during the conveyor system concept phase as the designs went through various changes and modifications,” Speer said. “Svendborg Brakes’ experienced project managers provide superior oversight and control of every project from order placement through installation.”
Svendborg Brakes has a global network of qualified local technicians who can commission and service its brake systems. “Our service technician team, based in Chile, speaks Spanish and is available on short notice. They have all the required South American certifications to work at mine sites throughout the continent,” said Speer. “These were very important Svendborg Brakes advantages for this particular project.”
The picture shows groupings of six Model BSFB 650 spring-applied, hydraulically-released, dual-spring caliper brakes, acting on 2.7 m diameter steel brake discs, serve as on/off holding brakes at the head of the various OGP1 conveyor sections
