This article originally appeared in International Mining Engineer.
Integrated Automated Sensors Warn of Problems While Minimising Risk to Mine Workers
Tapping into years of hands-on experience in the mining industry, Dion Wilson at Ultimate Positioning Group (UPG) in Western Australia, specialises in providing turnkey mine monitoring solutions that minimise the time staff members are exposed to the numerous inherent safety risks associated with mining operations. He places a strong emphasis on automating and aggregating different sensor technologies into a single software solution, to enable a multidisciplinary approach to data visualisation, analysis, reporting, and real-time alarming.
Wilson has been actively involved in the supply, integration, commissioning, and support of multiple systems throughout numerous mines in Western Australia. As a member of the Western Australian Trimble® distribution network, UPG supports its customers with the provision of equipment and software related to the Trimble portfolio of products and also integrates third-party solutions to form a cohesive solution, all under one umbrella.
Emphasis On Safety
There is a strong commitment by mining companies to improve worker health and safety by developing mature programs based on the latest technology, advanced equipment, and rigorous procedures. Integrated mine monitoring systems go a long way toward capturing important complementary data points about site conditions to better predict failures and identify risks to mine safety.
“The dedication by mining companies to developing and continually improving safety standards has dramatically reduced the number of fatalities and serious injuries, to a mere fraction of levels seen in decades past,” says Wilson. “Nevertheless, continued efforts to improve best-practice and safety standards are part of sustained initiatives to reduce these even further.”
A complex mining operation offers a multitude of monitoring opportunities, such as environmental and weather monitoring, tailings facilities, seismic events such as blasting and earthquakes, open pit slopes, groundwater, and structural monitoring of mine infrastructure such as crusher facilities. Wilson believes it is a safer approach to separate personnel from hazards, as opposed to controlling and minimising the risks they pose, so automating the collection and transmission of monitoring data improves safety by decreasing the hands-on work.
Automation and Complementary Data
When implementing a mine monitoring system, the main goal is to gather different types of information to facilitate observing and analysing areas with differing levels of risk. Often these devices complement each other–such as a radar sensor and an optical (total station) sensor–and a multidisciplinary approach facilitates a more holistic analysis opportunity.
Automation has brought numerous improvements to mine monitoring systems, with a primary benefit being the reduction of the amount of time staff spend in the field. Prior to automated systems, data typically had to be measured or downloaded manually, requiring staff to be exposed to mine operations on a regular basis. As mining operations are commonly quite dispersed, this process was also extremely time-consuming. Automation has both improved personal safety and virtually eliminated fieldwork to retrieve data. In addition, monitoring with automated sensors allows data acquisition frequencies to be based on project requirements, rather than balancing the needs of what is required versus what is practical.
Typically, mine monitoring systems encompass optical measurement equipment, customised remote power, and communications systems, cyclone-rated instrument shelters, as well as a host of other sensors. Depending on the situation, many different types of geotechnical, weather, or structural monitoring sensors may share the same infrastructure backbone.
“Although it is fair to say that all mines likely require some form of monitoring at some point, the vast majority of deployed systems are typically installed on open-pit operations, with the geotechnical engineering challenges at each individual operation determining the specifics,” explains Wilson. “Physical characteristics of the mine would then further dictate the extent, frequency, and nature of monitoring needed. This ultimately determines the implemented systems and sensors.”
Sometimes surrounding areas, not directly within the ore extraction area, form part of the wider context of monitoring requirements, for example, groundwater monitoring. Australian mines are also not limited to a single location, and it is common for a single mine to have multiple mining areas that can be separated by large distances of 10-20km or more.
Automated systems use existing site-wide communications such as Wi-Fi meshes or LTE systems for data transfer, but where this is not available, bespoke systems are provided by the dealer to facilitate communications. One modern approach to data storage and transfer is to use the Trimble Settop M1 total station controller, which stores round measurement data locally. This data is then automatically downloaded by the software as it becomes available, resulting in one of the most robust solutions by ensuring that round measurement data is secure, even if the communication system is offline.
Something For Everyone
Trimble’s monitoring portfolio is continually expanding. The firm’s core products such as total stations, GNSS receivers, office, and field monitoring software, and monitoring controllers have formed the mainstay of mine monitoring in the past. However, support for third-party sensors in the Trimble 4D Control™ monitoring software, as well as partnerships with other significant equipment suppliers, has seen typical mine monitoring programmes include a variety of other sensors. “We build comprehensive systems that may include wireless geotechnical sensors, digital weather stations, vibration and crack sensors, and SAA/inclinometers, not to mention emerging technologies such as visual monitoring processes and terrestrial laser scanning,” Wilson says. “With so many options, we can always deliver the right solution for the situation.”
All Trimble products are manufactured with IP ratings that facilitate use in the harsh climates that are the norm at Australian mines. This includes ambient temperatures of up to 50°,C which can often be higher in a monitoring shelter or mining pit. In addition, some of the equipment and related accessories need to be able to withstand extreme weather events such as cyclones, which are common across many mines. In particular, the S and SX series total stations are extremely robust and there are instruments still in use after more than 10 years of service, running continuously under harsh conditions.
Most mine monitoring systems benefit from combining different sensor types to build a multidisciplinary approach. Complementary data improves the likelihood of identifying problems with early warning to avoid damage and injury. Legislative mandates and individual company goals for worker and public safety influence the distribution and type of sensors selected from the myriad options available today.