Replace active tags for a better environment and cost-savings!

In a typical iron ore mine of LKAB in Lapland in Northern Sweden, about 30 huge 80-ton wheel-loading-machines are manoeuvred by skilled operators around the clock. All mining is today underground leading to a perforation of the ore body by an extensive network of tunnels through which the loading-machines circulate. 

After a blasting the detached rocks are picked up by the loading machine and discharged at a shaft for further loading on railroad wagons deeper down. The ore varies in quality from location to location and it is important to concentrate on the best ore and leave the lower qualities as well as all the waste rock. The quality is mainly determined by its density, i.e. the weight of a full scoop.

The benefit of an RFID system is in this case not only to keep track of the loading machines but especially to record in which location the most iron-rich ore was found.

The early project

In 2007 the system integrator Softcenter developed the whole mine production SW system and introduced RFID in the iron ore mine of Malmberget. Active tags were mounted at strategic locations; among those were the sites for loading and discharging the ore.

The loading machines were equipped with onboard computer and an RFID reader & antenna, to determine its logical position in the mine. The computer communicates on one hand with the

reader (over TCP/IP, via a local network) and on the other with the higher management systems using the WLAN in the mine. The onboard computer will associate the information of the location with all other relevant data, in particular the number of scoops that have been loaded and the weight of the load. 

As a recognition of their groundbreaking achievements and innovative thinking, RFID Nordic granted LKAB and Softcenter the prestigious Guldtaggen and Minitaggen awards in 2007.

Upgrading to UHF

The active tags proved to be expensive in purchase and maintenance. Environment friendly

Thomas Björnström, Managing Director, Softcenter.

and inexpensive passive tags seemed a more attractive alternative. After extensive testing the old technology has now been replaced by a UHF system from Scirocco, comprising R600 'Core' readers, A100 antennas and the T500 heavy duty tags. The verified reading distances of more than 7m, proved sufficient. The tags are hung on the rock wall so as not to obstruct in the narrow tunnels.

As a next step a similar system will now be introduced in the LKAB mine of Kiruna.

Future new possibilities

The iron ore is discharged in shafts to subsequently be loaded on railroad wagons, to be transported to the port of Narvik or the steel works in the coastal town of Luleå. As a future extension of the RFID project, these railroad wagons could also be provided with UHF tags. Strategically placed readers would then make it possible to trace the iron ore throughout its whole journey, from the depth of the mine to the port or steel works! For security and other reasons it is in a mine important to know where staff and visitors are. By attaching tags to the helmets or jackets and mounting readers in relevant places, this can easily be achieved with UHF RFID, as recent studies in mines have indicated. An access control and tracking system for all vehicles in the mine is furthermore easily created in this way.