Risk Management: The Latest Technologies for Mines
Developing and maintaining a working risk management program is a key necessity for any mine. Worldsensing engineers joined mining experts from Australia and South Africa in a webinar to discuss the challenges mining owners and engineers face when designing a risk management strategy. The monitoring professionals from mining technology companies Ramjack Technology Solutions and Geomotion Australia shared how they help mining companies use the latest monitoring technologies such as the wireless monitoring system Loadsensing to mitigate risks and increase ROI.
Moderated by Worldsensing’s Marketing Manager, Karen Figueroa, the expert session featured:
- Ben Scott: Instrumentation engineer with substantial experience in geotechnical instrumentation, automated data logging systems and presentation software from his projects in Western Australia, Canada, Sudan and Vietnam, Geomotion Australia, Australia.
- Stéphane Cantin: Mining engineer with over 20 years of experience in mining technology working on mine planning software and real-time technologies, Ramjack Technology Solutions, South Africa.
- Ángela Lluch: Geologist & construction engineer with over ten years of experience as a consultant in geotechnical instrumentation and monitoring, Worldsensing, Spain.
- Fernando Pérez: Mining engineer expert in wireless technology and partner management in Latinamerica and Africa, Worldsensing, Spain.
Risk management: the realities mines are facing
For mines, implementing measures to ensure risks are managed properly is mandatory. While the collapse of the Brumadinho tailings dam in Brazil shows that structural failures are a serious threat, efforts to reduce and ultimately avoid risks are often taken on a reactive basis. To avoid structural failures and run safe operations, mining operators and engineers should create and work with a proactive prevention plan.
Fernando Pérez, mining engineer and monitoring expert at IoT pioneer Worldsensing, summarizes the main industry requirements and monitoring pain points mines face related to effective risk management.
According to Pérez, the following two industry drivers have an impact on how mines manage risks in general:
- Occupational health and safety hazards: improving workers’ lives and ensuring the highest health and safety standards are some of the top industry challenges.
- Compliance with insurance regulations: mining companies need to ensure that they have all the tools to demonstrate that they are compliant with all the required regulations.
Peréz then moves on to look at the four challenges mines face when trying to mitigate risks by means of asset monitoring:
- High cost of mid to long-term monitoring: costs connected to manual readings and cable maintenance are high. New monitoring technologies can improve the cost-effectiveness of operations.
- Monitoring points are spread over large areas: accessing instrumentation deployed in remote mining environments is usually difficult and can pose threats to workers.
- Working environments are constantly changing: mining environments are dynamic and can suffer significant changes in seconds, failure can occur rapidly with little visible warning.
- Cables are vulnerable to physical damage: maintaining cables is challenging as they can be easily damaged during operations.
A new approach is to digitize existing sensors through digital data nodes to receive real-time monitoring data. When having access to real-time information, e.g. open pit mines can detect threats like cracks in dams early on. Engineers are then able to predict risks and can progressively abandon reactive actions to increase safety.
How mines monitor risks
While monitoring risks in mines is now an industry standard, historically, since the 1930’s, doing so was based on manual readings of the mining infrastructure. Over time, several industries needed to enhance their monitoring programs which made them push for cabled systems; with cables being widely adopted in the 1970’s. Nowadays, Internet of Things (IoT) technology has made it possible for mines to digitize existing sensors and monitor assets like tailings dams, slopes and underground galleries remotely.
Slope Stability in Open Pit Mines
After looking at the history of monitoring risks in mines, Ángela Lluch, engineer and wireless monitoring expert a Worldsensing, explains how in open pit mines, monitoring pit walls is crucial to foresee potential ground failure.
“Mines need to monitor the slope stability of crest and faces, with pore water pressure being a key parameter to ensure, for example, the effectiveness of a mine’s dewatering system”, Ángela Lluch, Geologist & Construction Engineer at Worldsensing.
With a network of singled tip or multi-point level piezometers, pore water pressure can be monitored to detect lateral instabilities of the slope. “While slopes may become unstable when overlaying material is removed, mines can control the ground through chains of in-place inclinometers and by monitoring potential vertical displacements by means of extensometers or settlement cells” Ángela points out.
Considering the average size of open pits, which are typically spread throughout several kilometers, a cabled solution seems less efficient due to the time it takes to plan the configuration and cost involved to finance the overall quantity of cables needed.
The risk of tailings dams failure
Tailings dams is the other crucial element that mines need to control. Liquefaction of mine and metallurgical wastes due to earthquakes is one of the main causes of failure of tailing dams in the world. A high degree of saturation in mine and metallurgical wastes stored in dams favours the liquefaction and a comprehensive monitoring system can help miners to survey key parameters, such as the phreatic level, at all times. To monitor the phreatic level, piezometers should be installed in the embankments or their foundations to monitor changes which may be critical to stability.
How does a wireless monitoring system work?
Wireless systems can suit the majority of mining monitoring needs:
- Critical assets: wireless IoT technology can be used in open pits, tailing dams, underground operations, and can also be used to monitor key weather parameters such as temperature, humidity, barometric pressure and water evaporation.
- Hard-to-access areas: A single gateway can cover the whole extension of a mine as it is able to reach distances of around 15Km / 9 miles.
Case study Boddington Gold Mine
After looking at the benefits of wireless monitoring for mines, Ben Scott, instrumentation engineer at Geomotion, presents the Boddington Mine case study, a gold and copper mine operated by Newmont, located 120 km from Western Australia’s capital city, Perth. This operation already had a monitoring programme with over 130 piezometers to monitor water level installed across 45 locations. Readings were collected manually by site personnel, many times having to travel to remote locations.
In order to automate the collection process, Geomotion proposed a wireless monitoring system using Loadsensing vibrating wire 5-channel nodes that send data to a centralized gateway.
Newmont now has data streamed and presented directly in their data management software and automatically fed into Boddington system for data analysis.
“The mine operator really sees the value of adopting the wireless solution. Now they have a fairly robust, easy to deploy product, with a fully automated collection of data. Frequency of readings can be increased and data can be accessed at any time. The mine operator is getting much more information than with the original data collection method”, Ben Scott, Technical Manager of Geomotion Australia.
As benefits of using this real time solution, Ben highlights that the mine could minimize safety risks and reduce costs of personnel frequently attending different locations. Using LoRa connectivity enables long-range communication and the low-power consumption batteries minimize the need for frequent maintenance.
Case study Remote Tailings Dam Management
Stéphane Cantin, mining engineer and mining technology expert at Ramjack Technology Solutions, presents the second case study. In Stéphane’s experience, tailings dams pose common threats and environmental concerns worldwide. While some countries have more advanced legislations, in others, tailings dams were constructed a long time ago and standards are needed to move ahead. For all of them, tailings dams are a liability and operators have to manage them properly over the entire life of the mine.
“Every hard rock mine has a tailings dam, it is an issue affecting a lot of people in the mining industry. Yet sometimes little attention is paid to the tailings dam until you start to have some problems. Wireless technology can help us reverse this management done ‘by exception’ “, Stéphane Cantin, VicePresident Execution Excellence at Ramjack Technology Solutions.
In terms of technical requirements, a monitoring solution has to be cost-effective, pervasive, able to provide continuous monitoring ready to detect any changes starting to occur, and needs to be scalable. Current monitoring systems integrate piezometers to monitor groundwater levels but also depth meters to know the level of water content in the tailings dam at key points and inclinometers for an early warning in case of slope instabilities.
Stéphane also stresses the importance of battery power as running electricity to these locations is really difficult; having multiple years of battery life is a fundamental point.
First steps to get started with wireless monitoring
After considering the benefits obtained by mines presented in these two case studies when implementing a wireless technology monitoring solution, Fernando focuses on the four elements necessary for mine corporations that would like to go wireless:
- An internal IoT champion,
- A comprehensive IoT system,
- Smart devices, able to work in mine environments,
- A proof of concept initial phase to make sure that all the hardware and software can be tested and adjusted to project conditions.
When wanting to start deploying a wireless monitoring system, there is one important thing to look out for: working with sensing technology able to automatically adapt to changes in the sensor network setup is a crucial factor to examine when evaluating a potential solution.
“Every time a new device is included or removed from the network, the sensor network needs to be capable of updating itself without any manual reprogramming by an expert”, Fernando Pérez, Mining engineer expert in wireless technology at Worldsensing.
Fernando closes the webinar session by presenting a cost comparison exercise for two South-African mines showing an estimation of the savings percentage of using a wireless monitoring system compared to cabled and manual solutions. According to the results, mining operators can achieve savings from 20% (5 years) to 70% (20 years) when adopting a wireless monitoring solution.