HX Belt Monitoring improves maintenance predictability at VKG Ojamaa Mine
When Viru Keemia Grupp (VKG) faced increasing conveyor belt failures at its Ojamaa mine, it knew traditional monitoring methods were no longer enough. With a 12.5-kilometer belt critical to continuous production, VKG needed a solution that would detect early-stage damage, prevent unexpected shutdowns, and improve operational safety. With ROXON’s HX270 Belt Monitoring system, VKG transformed its maintenance approach — reducing downtime, extending belt life, and ensuring production reliability.
Background: Keeping a Critical Conveyor Moving
Viru Keemia Grupp (VKG) is a large, privately held Estonian industrial enterprise, whose main product is shale oil. Their shale oil is produced from oil shale mined from the Ojamaa mine in Eastern Estonia, where the production of oil shale dates to 1924.
A critical part of the mine is a 12.5 km long conveyor belt, which connects the mine to a processing plant, where the shale oil is separated from limestone and refined to oil shale. Running at 3 meters per second, the complex conveyor has several turns left and right, up and down as well as over 1,5 km of bridges and tunnels.
“The belt needs to operate 23 hours per day to ensure efficient operations for all 530 employees at the mine. Once a week we have a longer maintenance break to ensure everything works,” explains Arnold Villers, director of the mine’s surface operations.
Given the critical role the conveyor plays, maintaining its reliability is paramount. Unplanned downtimes can severely disrupt production and workforce scheduling.
The Challenge of Identifying and Predicting Belt Failures
The Ojamaa conveyor was originally erected in 2012. As the first decade of operations neared its end, VKG started having more and more issues with the reliability of the belt. Tears and other breakdowns occurred frequently and caused additional downtimes.
Initially, VKG relied on traditional belt monitoring methods. The conveyor belt was equipped with internal steel cable loops every 100 meters, monitored by a system to detect internal damages. However, no technology was available to monitor surface damage or early-stage wear. Traditional loop-based detection systems also often triggered false stops.
Inspections to the belt were manual and labor-intensive. Workers would visually inspect the belt using video cameras during slowdowns or physically walk along the conveyor to identify faults — an overwhelming task given the length of the belt. The process often missed early warning signs of future failure.
Unseen damages grew into major failures, leading to unplanned maintenance downtimes. The downtimes severely hurt the productivity of the entire operation and complicated operational planning.
“It can easily take 12 hours to fix an issue in the belt. Besides the vast operational costs, a sudden failure at the belt can mean that the evening or weekend plans of many workers have to be rescheduled,” Villers explains.
Faced with growing maintenance challenges and operational risks, VKG recognized the need for a more advanced, continuous, and precise monitoring solution.
Solution: Condition Monitoring with Real-time Laser and Machine Vision Technology
After exploring options to improve belt condition monitoring, VKG discovered ROXON’s HX270 Belt Monitoring system. It’s a cutting-edge solution utilizing machine vision and laser technology to monitor the condition of conveyor belts in real time.
“Unlike traditional systems relying on embedded sensors, HX270 Belt Monitoring scans the entire belt surface continuously with millimeter-level resolution. This enables identifying even the smallest surface anomalies without the need for embedded loops or antennas,” explains Harri Pikkarainen, Product Manager for HX Systems at ROXON.
Key benefits of the installed solution included:
- Immediate detection of surface damages such as cuts, tears, and deformations.
- Continuous 24/7 automated monitoring.
- Ability to track damage progression and prioritize repairs based on real-time severity.
- Ability to automatically stop the belt at the exact point where maintenance is required.
The installation was fast, thanks to the seamless collaboration between VKG and Roxon.
“VKG’s proactive preparation enabled a smooth setup, with the installation completed in a matter of days,“ Pikkarainen looks back.
Villers agrees: “ROXON and Harri handled the installation professionally and quickly. After the installation, our crew received thorough training to interpret the monitoring data and take corrective action effectively.”
Based on the initial lessons learned from the operation, the set-up was further developed. Now, both ends of the conveyor have independent HX270 main units, allowing precise location tracking of damages based on a defined zero point. Consequently, the belt can be stopped at the right location without waiting for a full conveyor cycle, a major operational advantage given the conveyor’s 2-hour loop time.
The Results: Fewer Unplanned Stops, Safer Operations, and Longer Belt Life
The deployment of HX270 Belt Monitoring at VKG’s Ojamaa mine has delivered outstanding results:
- Fewer unplanned stops: Early detection of tears enables planned repairs during scheduled maintenance windows.
- Extended belt life and safety: Small damages are addressed immediately before they evolve into major problems, preserving belt integrity and improving the safety of employees and machinery.
- Higher operational efficiency: No need for manual belt inspections during operation, allowing maintenance teams to focus on corrective actions.
The ability to detect and locate even minor surface damages in real time has improved VKG’s maintenance operations. Instead of reacting to failures, the team can now proactively manage repairs based on the findings that HX270 Belt Monitor produces.
“Trying to visually inspect a 12.5-kilometer conveyor moving at 3 m/s is unrealistic, and analyzing hours of identical video footage would drive any worker insane,” Villers explains.
With HX270, every square meter of belt surface is automatically monitored around the clock, providing complete visibility without human error. Humans still make the decisions though, as Villers observes: “At one point we saw that the belt was almost broken but estimated that it would still last a few days until the next maintenance break. Unfortunately, the belt did not last and, so we had a unwanted maintenance break.”
Next Steps: Expanding the Solution to Future Mining Projects
Building on the success at Ojamaa, VKG is integrating HX270 and HX170 Belt Monitoring into its future expansions. A new mining area is under development to replace the Ojamaa mine by 2029. This project includes a new 6.3 km conveyor system, which will handle up to 2,000 tons of ore per hour.
“Obviously we’ve been very happy with the solution, otherwise we would not have chosen it for the new conveyors as well,” Villers laughs.
By ensuring their conveyors operate with maximum reliability and safety, VKG secures the future of its mining operations — setting a strong example of industrial innovation.
“VKG’s innovative spirit and commitment to adopting leading-edge technology have been key drivers in this transformation,” Pikkarainen concludes.