Gold Fields Limited owns and operates 12 gold mines in South Africa, Ghana, Peru and Australia, producing roughly 2.1 million gold equivalent ounces annually. Gold Fields is listed on both the Johannesburg Stock Exchange (JSE) and the New York Stock Exchange (NYSE), and employs roughly 50 000 people globally.
South Deep Gold Mine, Gold Field’s only operational mine in South Africa, is situated 45 kilometres southwest of Johannesburg, is comprised of two shaft systems and a central metallurgical plant.
This project involving Rockwell Automation falls within Gold Fields’ long-term vision: ‘To be the global leader in sustainable gold mining,’ and is a flagship growth project in South Africa.
The metallurgical plant at South Deep Mine was upgraded in 2011/2012 to increase its throughput. This involved the addition of a second ball mill circuit, a pebble crushing circuit, an additional thickener, four leach tanks and an extra elution column.
To better manage reagent, energy and water usage throughout the upgraded plant, while at the same time improve the quality of mine tailings, South Deep Mine needed a complete control and reporting system upgrade that would integrate all existing field systems with the new ore processing systems. This would have to allow for faster, more informed business decisions at a management level, and help the mine meet its long-term sustainability objectives.
Gold Fields also needed to reduce the risk of unplanned downtime with a control system that could seamlessly integrate all field devices, plant control, visualisation, reporting and overall performance monitoring into a single, simplified system that could also be expanded in future plant upgrades.
The metallurgy plant was originally based on Rockwell Automation RSView®32 component-based HMI and L62 controllers for process monitoring and control. This required further optimisation: all I/O, interlocks, sequences and other process routines needed to be re-evaluated to eliminate unnecessary complexities throughout the new control system.