Jun 02, 2008An Australian mining company has rolled out an underground digital network incorporating radio frequency identification to improve safety by tracking its staff and equipment. Anglo Coal has just completed the installation of RFID readers throughout its Grasstree Mine in Queensland, while also fitting tags to the miners' cap lamps, vehicles and tools. According to technology supplier NLT Australia, the mine is the first in the world to be certified intrinsically safe (IS) for an entire underground digital network and RFID system.
Anglo Coal initially contracted NLT Australia to develop a system that would provide two-way messaging and tracking via the miners' cap lamps. The main objective was to improve safety for those working underground by better monitoring such employees throughout the mine. But it also hoped to cut costs by tagging equipment to better track tools between shifts.
"Tagging tools was a major selling point," says Tim Haight, NLT Australia's managing director, "because it is very easy to misplace equipment in an underground mine, and time is wasted trying to find the tools. By using RFID, Anglo Coal could quickly locate staff and tools when they are needed."
NLT developed a digital network with an open-standard Ethernet backbone capable of supporting two-way messaging, RFID tracking and environmental monitoring. Wavetrend Technologies, a U.K. supplier of active RFID tags and readers, was then contracted to provide RFID hardware that integrated into the digital network and communications system. Wavetrend fitted 200 cap lamps with active RFID tags, operating at the 433 MHz frequency. Fourteen readers were installed throughout the mine at 100-meter (328-foot) intervals, along with 14 wireless nodes.
When a tag is read, the data is transmitted to a wireless access point and relayed via fiber optic cable to the mine's control room. Customized proprietary software, known as NLT Digital Suite, sits on top of the digital network to filter that data. The information can be utilized to monitor the location of staff members, vehicles and equipment, as well as search for personnel on-site, reassign staff and notify workers of an emergency.
"The system provides increased safety, but also increased efficiency, as people can be located more quickly and directed around the mine where needed," Haight says. "But the data can also be filtered so that the company can search for an individual, a group or even people with particular skills. For example, it could immediately find anyone within the mine with first-aid skills."
The system was tested extensively at NLT's facilities in Caboolture, Queensland, with range testing of the readers performed on-site at the Grasstree mine. Research and development of the system lasted about three years, with IS certification taking an additional year.
NLT initially rolled out a small number of RFID readers and tags to a limited section of the mine in November 2007, before gradually rolling the technology out to the remainder of the mine this year. According to Haight, the final stage was completed in recent weeks. "It was quite a challenge working underground," he states, "as we had to be sure not to disrupt the mine's operations. We also had to ensure all the technology was protected because it would be exposed to moisture otherwise, which would damage the system. But we overcame the challenges and the rollout has been very successful."
Peter Harrop, chairman of RFID market research firm IDTechEx, says mining companies have traditionally lagged behind other industries in adopting radio frequency identification. "But RFID has a proven safety benefit in a mining environment, and it is recognized as a best practice worldwide," he says. "This is an example of the mining industry waking up to the benefits of a real-time location system for evacuation or tracking equipment." According to Harrop, mining companies in China, Sweden, Norway and other countries have deployed RFID in recent years.
But Haight says that by rolling out the first IS-certified digital network and RFID system, Anglo Coal will experience additional benefits as well. Its tracking staff, he notes, will be able to improve safety and ensure the company can find workers at any particular time, while tagging tools and equipment should cut costs by making it easier to recover misplaced items.
In addition, NLT Australia has developed a new system in which an RFID reader could be placed within a miner's cap lamp, with RFID tags distributed throughout the mine. The new system would be cheaper and quicker to install, Haight says, because fitting tags underground is simpler than fitting RF readers throughout the mine. It would also eliminate the need to provide power to underground readers, as they would be installed in the cap lamps.
"It would provide even more precise tracking," Haight claims, "as more tags could be distributed around the mine than readers. If Anglo Coal decides to expand the system to include this, it would give them a virtual underground GPS [global positioning system]."
