Nov 13, 2007CVRD Inco, a wholly owned subsidiary of the Brazilian mining company Companhia Vale do Rio Doce (CVRD), is testing RFID technology to track ore as it's extracted, crushed and sent to production mills. By improving its visibility into the amount and grade of ore it mines daily, the company hopes to better prepare its processes for turning the ore into quality ingredients for stainless steel and other metal alloys.
Headquartered in Toronto, CVRD Inco produces nickel, copper, cobalt, platinum, palladium, rhodium, ruthenium, iridium, gold and silver. This month, the company completed installation of an ultrahigh-frequency (UHF) RFID system at its Stobie Mine in Sudbury, Ontario, about 40 kilometers north of Toronto. The system incorporates customized Avery Dennison EPC Class 1 Gen 2 RFID tags and Motorola mobile and fixed UHF RFID interrogators.
To develop, test and implement its RFID system, CVRD Inco enlisted assistance from Ship2Save, a Montreal-based RFID services company specializing in the transportation, manufacturing, warehousing and sea-freight industries. The installation includes Ship2Save's Raw Material Tracking software, based on the vendor's Operation Management System RFID platform. The tracking software includes a dashboard, or graphical visual interface, that offers a real-time view of ore extractions. It can provide alerts and reporting tools to inform end users about specific events, such as how much ore has surfaced within a given time, and it can also be configured to transmit the alerts via audible, visual or electronic means.
Ship2Save has ruggedized and customized the tags to withstand blasts and the crushing process that breaks up large rocks into smaller sizes. The specific reinforcements are confidential, but Konrad Konarski, Ship2Save's director of alliances, says the tags are protected by an acrylonitrile-butadiene-styrene (ABS) base cover and other internal reinforcements.
"Mainly, we want to use RFID to be able to monitor the quality of ore from the underground," says Mark Palkovits, senior geological technologist at CVRD Inco. By knowing the value or grade of the ore, as well as maintaining accurate yields, CVRD Inco can make sure it has the proper chemical mixes at the mills to produce, for example, nickel. "We blend the chemicals much like you blend ingredients in a recipe to make a cake," Palkovits explains. "With optimized information and upstream visibility of what—and how much—is going into the mills, we can optimize the chemicals needed in the mixing processes."
Typically, determining ore yields and grades is a manually intensive process leveraging pen and paper and a good deal of forecast modeling—an inexact science reliant on historical and current yield data to estimate future yields. "We have to budget a year in advance how many pounds of copper and nickel we'll produce," Palkovits says.
Using RFID to track ore from excavation to milling is no mean feat. After miners blast a specified area within the mine, one or two RFID tags are tossed into the resulting heap of ore. As the tags are deployed, a geologist carrying a handheld RFID reader scans the tags to collect their unique ID numbers, while also entering specific coordinates (accessed from a pull-down menu) documenting the blast site's location. "The mine is set up on a coordinate system, so everyone knows where they are at all times," Palkovits says. At the end of each shift, the geologists place the handhelds into docking stations to upload the tag and location data collected that day.
At the surface, the crushed ore is funneled onto a V-shaped conveyor belt, which moves at a rate of 300 feet per minute, carrying the ore to be dumped into train cars. Ship2Save has outfitted the conveyor belt with eight antennas and an XR440 RFID reader from Motorola. The interrogator is housed in a National Electrical Manufacturers Association-certified enclosure to protect it from dust, weather and other elements. The tag is read as the ore containing it passes under the antennas. The tag data is then fed into Ship2Save's tracking software, which passes the information on to CVRD Inco's back-end system.
"The tag may be floating on top or buried far below," says Eddie Ng, Ship2Save's project manager for CVRD Inco, "but our testing has revealed that the tag can be read deep into the ore." CVRD Inco employees can view the data anytime, by accessing real-time reports in Ship2Save's tracking software.
What makes this RFID tracking system unique is that the tags are not physically attached to anything. Rather, they are mixed among the rock being tracked. What's more, not only are the tags mixed among the ore from a specific blast site, the tags and ore from several blast sites are mixed together upon being moved into the passes.
To calculate yields that include grade values so the mining company can determine the appropriate chemical mixes, CVRD Inco uses modeling techniques. Now, all the collected tag data—from which each tag read can be associated back to a specific blast site within the mine—will be entered into the company's modeling system, which should greatly improve the company's insight into what exactly is being extracted from the mine, and when. That information will then be shared with the mill, so that the appropriate chemical mixes can be ready when the ore arrives.
CVRD Inco expects to run the RFID trial at its Stobie mine for the next 90 to 100 days. When this is complete—and if results are successful—the mining company hopes to expand the RFID system. "Once this is working well, we'll go into the next phase," Palkovits says. "We want to put the tags into holes in solid ground, and then set off blasts in proximity to these holes so we can track the ore from the blast site." In addition, the firm intends to use RFID to track the railcars moving the ore to the mills. "We currently move about 16,000 railcars a month, and right now we track that with pencil and paper."
Earlier this year, CVRD Inco began rolling out a Wi-Fi-based RFID asset-tracking system from Ekahau. Currently in use at its Stobie and North mines (the latter is also in Sudbury), the system is utilized to track how long it takes a truck driver to retrieve ore and transport it to its deposition site—a metric previously tracked using pen and paper (see CVRD Inco Mines Turns to Ekahau to Track Assets, Productivity).
