By Aaron Hand
Teck Metals in Trail, B.C., is the world's largest fully integrated zinc and lead smelting and refining operation, and the leading producer of copper, steelmaking coal and zinc, molybdenum and specialty metals. It consumes about 100 tons of rock per hour and deals with three-fourths of the periodic table elements, finding stray gold and silver in its mining process, but also less benign gases, liquids and solids that it must carefully manage in a very environmentally sensitive area along the Columbia River.
But the major zinc producer faced a significant need for modernization. The Trail location encompassed 19 plants, each with its own operations, its own control systems—from a mix of automation suppliers. The plants could not collaborate very easily or very cheaply.
The company faced other challenges as well, including increasing competition, growing pressure to meet environmental regulations, increased demand for productivity and flexibility, aging assets and an aging workforce, says Rob Zwick, superintendent of control systems at the Teck Metals Trail Operations. "That facility, in the late ‘70s, had over 5,000 people working there. Today there are 1,500," he says. "We weren't hiring anybody during those 30 years; we were downsizing on a continual basis. The workforce was getting older and older, and we suddenly thought holy mackerel, we've got everybody retiring in a short time span. All that knowledge is going out the door."
Teck Metals elicited the help of Invensys Operations Management, whose first strategy was to migrate everything to a common platform as much as possible. "We worked closely with Invensys," Zwick says, noting that they first tackled the control systems.
"With the changing workforce, having disparate control systems was a really difficult thing to manage."
Invensys migrated various distributed control systems (DCSs) over to the Foxboro I/A Series DCS. "Now people working with the control systems aren't having to learn or educate themselves on different platforms," Zwick says.
The migration kept the same form factors while reducing risk and reducing cost, according to Joe Fillion, value consultant for Invensys. "Also, they had issues with those systems hitting end of life." Invensys replaced cards and enabled easy and inexpensive wiring to brand new control systems, he adds.
Alarm management was a major issue, Fillion says, with operators getting about 6,000 alarms every day. "Operators just ignored them. It was too much," he says. "There are issues where the system might find environmental excursion, but the operators ignore it. It will shut the plant down if it goes too far. A valve might need to be replaced, but if the operators don't see them, there's no value."
Some 6,000 alarms per day translates to 3-4 alarms per minute, Zwick notes. Getting it down to 500 per day translates to one alarm every three minutes. To get there, the team looked at every configurable alarm, evaluating such factors as whether it was valid, how urgent it was, what its set points should be, and who should be notified. "We went through the entire plant," Zwick says. "We went through a large number of alarms that we evaluated. Now they've become completely manageable at the plant level."
The Teck plants were operating under a firefighting mentality, Fallion says, in which they faced unplanned downtime when a valve failed because they didn't know it had been failing for weeks. "Now they're better prepared and strategic," he says, noting that there are now maintenance alarms that are reviewed once a week to decide which are the most important to address.
The 19 plants each had their own DCS, PLCs and HMIs. "From a support perspective, it was a major issue," Fillion says. "It was very hard to get an operator from one plant to another plant. They were getting feed from other plants and feeding down to other plants. There was a lot of integration required with all these disparate systems."
The vision is to have a common HMI and common historian. With the amount of environmental regulatory constraints, the plants couldn't afford to lose data because of integration difficulties with multiple historians. "If you don't have the data, they assume you've had a violation," Fillion explains.
Not only will the Trail facilities move to the ArchestrA system platform as their common historian, but the corporate Teck group has selected Wonderware as the historian for all plants (there are 12 other locations besides Trail).
Teck and Invensys will continue to collaborate closely to go after other areas that are priorities, Zwick says. "For the exchange of data, the priority is that the exchange of data is secure," he says. "We have to eliminate single points of failure."
Future plans include dynamic performance measurements, empowering individuals out in the field, improving workflow processes, and integrating the quality control system into the manufacturing business.