Mines expand use of RFID systems to improve safety

For the past five years, Finland's Pyhasalmi mine has been using passive high-frequency RFID tags to record employee entry and exit, thereby ensuring the safety of personnel evacuation in emergencies. The mine's general manager, Kimmo Luukkonen, said the technology increases the efficiency and accuracy of the safety program by providing visibility to mine personnel. The company plans to use the HF RFID solution to monitor personnel carrying explosive detonators in mines.

This RFID solution uses Identoi's Idesco HF and UHF RFID Readers.

Pyhasalmi is one of the deepest and oldest mines in Europe. It is owned by a Canadian company called First Quantum Minerals. Rich copper and zinc are buried 1,400 meters underground. The mine has two drive shafts, one is used to transport miners down and up the mine, and the other is used to transport transport vehicles.

In 2009, the mine's managers began deploying an operational safety system that automatically identifies who is underground at a given time. This information is important because, in the event of an emergency evacuation, the company needs to ensure that everyone in the mine reaches shelter and to identify those who do not. Additionally, mines blast certain rocks to extract minerals, a process that also requires evacuating people.

Before deploying RFID solutions, the company manually tracked people in the mines. Nameplates for each employee hang on the wall at the mine entrance. When entering the mine, employees are required to remove their nameplate. When leaving the mine, employees re-hang the nameplates. This way, managers only need to look at the actual nameplate on the entrance wall to know who is inside the mine. However, this system was prone to error as employees often forgot to remove the nameplates. In addition, since visitors do not have nameplates, the system cannot record their information.

This RFID solution uses passive 13.56 MHz RFID tags (compliant with ISO15693 standard). The tags are small and can be attached to employee keys. All employees are required to carry this tag with them. The mine has a total of 220 employees, with a typical shift of 70 employees.

When entering the mine, the employee needs to place his blue RFID tag on the RFID reader at the door to read it. After the reader reads the tag ID number, it will upload it to the software. The employee's name will then be displayed on a large screen at the entrance. If an employee brings visitors in, the employee needs to enter the number of visitors on a touch screen connected to an RFID reader. This way, managers know how many people are inside the mine.

Employees go through the same steps when leaving the mine. Employees need to place their tags at the exit for the readers to read. This data will also be uploaded to the software. Managers can view it at any time.

In the event of an emergency, employees need to take refuge in 23 shelters in the mine. Two HF RFID readers are installed in each shelter, one for entry and one for exit. If an employee fails to arrive at a shelter, the mine can use voice communications technology to find them. Vaara said the system uses HF RFID technology because of the reading distance. Using UHF frequencies, the system may misread employees near the door.

In 2012, the mine installed UHF RFID technology to record trucks, vans and cars in the above-ground working area. To enter the area, vehicles need to pass through a gate equipped with an EPC UHF reader. Each authorized vehicle has an EPC UHF RFID tag installed on the windshield. This allows the reader to record vehicle ID numbers passing through the gate and create an entry and exit record.

This year, the mine also plans to use RFID technology to track detonators. Workers would use special Tools to inject explosive material into the hole and then insert the detonator. Detonator manufacturers will print the ID number on each product in the form of a QR code. When installing detonators in ditches, employees use handheld readers to read HF tags and scan the QR code to obtain the ID number and information of the detonator. Late last year, the mine planned to attach HF tags to detonators, which would simplify the work of its employees.