PT Freeport Indonesia (PTFI) was facing obsolescence of its Foxboro control system. The mining company put together a comprehensive modernization plan that included maximizing value from existing automation investments.
“Our primary mine is the Grasberg surface mine in Papua, Indonesia,” explained Bendang Sameto, APC engineer at PTFI, in a presentation about the mine’s various upgrades at Schneider Electric’s Innovation Days in Austin, Texas. “It will be closed, and we will move our mines underground. The crater is so wide it’s not feasible to mine from the surface any more.”
This transition to a completely underground operation comes on the tail end of a control-system upgrade that has already spanned 17 years. The operation includes crushers and equipment to transport the crushed ore to stockpiles. After crushing and grinding and converting to slurry, it’s then transported to a pipeline, which carries it to a dewatering plant portside, where it’s readied to be sent by ship. Average throughput topped out in 2001 and 2009 at 238,000 tons/day.
During that span, the oldest workstations and software were upgraded, and new enclosures were added. The 12-node cable local area network (LAN) was upgraded to fiberoptic. Controls were upgraded from CP40A to the Field Control Processor 270 (FCP270) with Field Device Systems Integrator (FDSI).
“We have 800 Fieldbus Modules (FBMs) installed,” said Ade Jaya, control systems leader at PTFI. The Grasberg mine also includes 8,000 terminations of field wiring, 950 control loops, about 6,000 calculation blocks and 730 operator graphic displays.
Refurbished workstations were purchased and older ones were upgraded to a common standard with a system software upgrade, as well.
“We migrated from LAN to a mesh network, which can route around multiple faults, unlike the A/B redundant network,” said Jaya. Additional nodes were brought on the mesh network, and the fiberoptic infrastructure was improved.
The older controllers and gateways were upgraded because of obsolescence and their limited capabilities. “As I/O points increased and control loops have become more complicated, some of these controllers have become overloaded,” said Jaya.
Foxboro’s current offering of controllers and workstations all require a mesh network, he explained. “Establishing a good network design ensures total flexibility into the future,” said Jaya. This also allowed PTFI to upgrade the FCP270 to FCP280.
