Open pit mines are getting bigger, and as they get deeper, the importance of understanding and controlling slope stability increases. A wall failure can not only lead to safety issues, but also to significant losses due to production interruption and rehabilitation work.

An effective slope monitoring system aimed at managing potential large-scale instabilities as well as local scale movements is a critical component for risk management practices in modern open pits. Slope monitoring radar have been extensively exploited for displacement monitoring and alert generation in natural and engineered slopes thanks to the high accuracy, long range capabilities, wide area coverage and opportunistic character of the system (no need for artificial reflectors to be installed on the walls).

The Italian radar manufacturer, Ingegneria dei Sistemi IDS, with more than 90 installations in mines all around the world, is helping to define a new standard in safety-critical slope monitoring. The company says its “long record of successfully tracked failures has been possible by the innovative radar technology employed by the IDS IBIS radar. The IBIS system is based on a Synthetic Aperture Radar (SAR) technology which is able to provide the highest spatial resolution at the longest range distance

available on the market, along with the fastest acquisition time.“IBIS-FM is able to measure the entire range of spatial scales of the typical slope instabilities within a pit, from bench scale to overall slope failures passing through multi-bench and interramp scale failures and the entire temporal scale of the slope instabilities, from fast movements (cm/day), to very slow movements (mm/year), becoming a critical component for risk management practices in modern open pit mines. These features enable [the equipment] to fulfil the needs of both safety critical slope monitoring and background monitoring of the largest mines currently in operation. The integration of those two concurrent aims is made still more effective by the employment of the new FPM360 system recently released by IDS. In fact, it extends the capability of critical safety monitoring collecting and managing data from multiple IBIS-FM systems which are displayed stitched together, providing 360° full pit coverage with still the benefits of monitoring resolution from sub-bench to multi-bench failures.”

A recent clear example of the IBIS effectiveness for safety critical monitoring in open pit mines is described in the IDS press release showing how its radar system helped Kennecott technical staff to increase mine safety and protect the lives of employees. Following the massive slide which occurred on April 10, Kennecott acknowledged the use of slope monitoring radar at the mine as part of their slope-stability monitoring activities.

“According to Kennecott, real-time data received through radar monitoring systems has been used to anticipate areas that have shown movement as well as to assist in short-term and long-term mine planning and to maintain a safe and efficient operation, before and after the slide.”

“The radars scan the entire wall constantly, capturing over 380,000 images every four minutes” Ted Himebaugh, General Manager of Integrated Operations at Kennecott told ABC 4 News.

IDS is pleased to recognise that these capabilities, unique to the IBIS radar system, have been openly acknowledged by Kennecott for the safety-critical monitoring of the northeast wall in the Bingham Canyon mine. The company says “geotechnical engineers can benefit greatly from the capabilities of modern slope monitoring radar, such as the aforementioned IBIS system, in collecting high resolution images of entire open pit slope faces over a short scanning period and at a long range, far removed from the areas at risk within the mine. These capabilities allow the radar to track the movement history of a mine wall from start to finish, by first detecting initial small movements and accelerations and then detecting the large movements immediately preceding a slope failure. Additionally, this type of system can also provide relevant alerts and alarms based on user defined velocity, acceleration or inverse velocity thresholds.”

“Due to their wide area of coverage, two of the three IBIS radar units installed in the pit at Bingham included the northeast wall where the slide occurred and supported the local geotechnical engineers in first detecting the movement in early February. The radar units measured the accelerating trend of the slide in March, indicating the progressive nature of the movement, which, according to Kennecott, reached a velocity value of 2 in/d on April 10, the day of the failure.”

Kennecott was aware of the slope movement and had been monitoring this movement for months in advance through a combination of radar, prisms, and geotechnical sensors. By the morning of April 10, all mine personnel had been evacuated from the area surrounding and below the slope that was predicted to fail. The slide occurred at approximately 9:30 pm that evening.

 This is an excellent example of how a modern slope monitoring program that integrates the most advanced technologies, such as slope monitoring radar, can support the decisionmaking process in relation to an impending slope failure at a large open pit mine such as Bingham Canyon.

GroundProbe cites another very interesting example of slope stability monitoring from Indonesia where the geotechnical team at PT Bayan Resources knew there was potential for improved coal recovery at a number of its mines. The location of the coal seams and the adverse geotechnical condition of the open-pit slopes meant that in areas adjacent to unstable sections of the pit the cost of additional overburden removal and the risks of coal extraction outweighed the benefits to production.

With declining global coal prices, PT Bayan developed a strategy to address these challenges. The mine undertook a number of pit design changes to economically optimise the coal seam reserves. Ground control systems were installed to enhance mine safety and provide reliable and accurate slope movement data to the geotechnical, mine operations and coal production teams. An upgrade of slope monitoring and reporting systems was carried out at four key mine sites. To maximise coal recovery in unstable pit areas, the GroundProbe Slope Stability Radar (SSR™XT) was deployed.

“The deployment of the slope stability systems at our key mine sites has empowered our geotechnical staff to be proactive in the communication of timely, accurate and reliable slide movement information to our mine safety, operations and production teams.” – Warren Tamblyn, Manager Mine Geotechnical Services, PT Bayan.

At the Wahana open pit, more than 8,000 t of coal were recovered from the low wall toe area, prior to the cracking, break-up and destruction of the coal seams in the slide mass. 24/7 monitoring with SSR-XT, in combination with Bayan best practice safety procedures, made the coal recovery possible with no injuries or loss of equipment – coal recovery value $1 million

Through a remote monitoring service, GroundProbe’s Geotechnical Support Services team notified PT Bayan of potential movement on a coal seam floor area. Equipment and personnel were removed from the site and SSRXT was left to monitor. Once the slide movement had stopped, PT Bayan, utilizing best practice mining and safety procedures recovered an additional 45,000 t of coal from the area below the slide mass – coal recovery value $4-5 million.

In the highwall area, Melak project in June last year, initial geotechnical assessment showed limited access for mining below the unstable highwall slope. A safety exclusion zone of 30-40 m was recommended, thus restricting coal recovery. The deployment of SSR-XT, allowed mining of the coal seam to continue down to another bench. An additional 12,000-14,000 t in this area of the open cut was recovered – coal recovery value $1-2 million.

The new RIEGL VZ-6000 is a high speed, high resolution terrestrial 3D Laser Scanner that offers an extremely long measurement range of more than 6,000 m for topographic (static) applications. It operates well in poor visibility and demanding multi-target situations caused by dust, haze, rain or snow. Being the Laser Class 3B companion to the VZ-4000, it is, due to its laser wavelength, exceptionally well suited for measuring snowy and icy terrain in glacier mapping and monitoring applications in mountainous regions.

The VZ-6000 is compatible with the wellproven RIEGL software package RiSCAN PRO for terrestrial laser scanning, RIEGL’s interface library RiVLiB, as well as the workflowoptimising software packages RiMONITOR and RiMINING. The software plugin RiMTA-3D provides automatic assignment of the correct MTA zones in multiple time around processing. RIEGL has also introduced a new airborne laser mapping system – the LMS-Q1560. This, it says “introduces a new era in high altitude airborne mapping. This new ultra high performance, fully integrated airborne laser scanner system within a single, self-contained unit features dual highpowered laser sources, dual optical receivers, and a common mirror built into the system, creating precise and effective data coverage on the ground.” The system has numerous potential applications in both the mineral exploration and brownfield mine arenas.”

The LMS-Q1560 can be operated at a maximum pulse repetition rate of 800 kHz providing an effective rate of 530,000 measurements/s on the ground, while operating at the demanding altitudes of such projects.  Range ambiguities due to regularly occurring and sometimes even dramatic terrain elevation changes are automatically resolved by RIEGL’s multiple time around processing software, RiMTA. The software manages up to 10 pulses in the air, simultaneously. This enables the user to do simple flight planning, even for difficult terrain. “The result is safe flight planning and flying, faster project processing and exceptional data quality”, says RIEGL.

Using a unique dual channel design – RIEGL has provided “an innovative forward, backward and nadir looking capability in this instrument.” This enables more effective and more accurate high point density data capture from different angles producing the best point spacing on the ground, even in challenging terrain. The LMS-Q1560 system design and calibration provides seamless integration of additional sensors and unprecedented customisation options to the user.”

Optionally, other sensors may be easily integrated; an IMU, a medium format aerial camera and the capability for a secondary IR camera to complete the system. With all these individual components integrated into one single instrument of compact design, suited for gyro-stabilised levelling mounts, the system installation is “simple and straight-forward.”

For 20 years, Soldata, a French company with subsidiaries around the globe, has pioneered sensor-based monitoring systems for use in tunnelling, beginning with work on the London Underground Jubilee line. Since Soldata first began demonstrating the value of real-time monitoring in tunnel construction, its importance has become very widely recognised – by insurance companies as well as the contractors actually doing the construction work.

But there’s another important innovation that has helped bring the 40 major tunnel construction projects Soldata have monitored to completion without incident: integration. The company believes using an integrated sensor data management platform significantly increases the effectiveness of all monitoring systems, delivers more reliable information and leads to better and timelier decisions.

Soldata says that in slope-stability monitoring “only a combination of different technologies can provide a global understanding of the situation. However, data from these monitoring systems, their analysis and alarms are often managed on an individual basis. Those multiple isolated systems with less than optimal data storage or management could create inefficient and possibly ineffective analysis of data. This often results in a system of multiple non-interfaced alarm criteria.”

At Codelco’s Chuquicamata copper mine in Chile, by effectively transforming the slopestability monitoring of one of the world’s largest open-pit mines on the planet, Soldata’s integrated sensor data management system, Geoscope™, has proved its value after being adapted from its application in tunnelling to play an equally crucial role in mining.

Whereas Codelco had previously used a combination of independent monitoring systems that generated data in a number of different forms from around the site, Geoscope has streamlined the whole process.  As Eric Audigé, the MD of Soldata Oceania, explains, “We translate raw data into useable information that allows operators to take decisive action when it’s needed. Our system cross-analyses geotechnical, surface or structural and environmental data from any type of sensors in real-time and provides unequalled situation awareness and insights.”

One of the key differences of the Geoscope system Soldata set up for Chuqui compared to those used in other industries is that it includes slope stability radar in the same platform as geotechnical sensor data (prisms, piezometer, extensometer, visual inspections…) and crossanalyses the whole package.  Generating the bulk of data, radars are notoriously hard to integrate with other sensors and manage efficiently, so its incorporation represents a real breakthrough.

The integration of data from such diverse sources means that all findings can be instantly cross-correlated, massively reducing the risk of false alarms. Also virtual sensors are created to take into account mine-specific factors or provide better insights.

Under the previous complex of individual systems, a reading from a single sensor could trigger an alarm. The Geoscope system gathering and processing all data on a single platform not only streamlines the operations but most of all allows for developing alarm strategies based on multiple technologies with cross correlation of alarm validity. If there is a potential problem, its location can also be pinpointed more precisely by comparing data from multiple sources from the same vicinity before confirming critical movement, Soldata says.

Easy standardisation of procedures, data security and accuracy are also the benefits of an integrated approach, allowing users to focus on investigation and remediation.

“Now that the Chuqui example has shown the way, similar off-the-shelf integrations are on their way to increase the safety and efficiency of mining operations in Australia and the rest of the world,” Audigé explains.  “By drawing on new technologies that have already been ‘road-tested’ in other, comparable industries, miners can avoid the possible teething troubles associated with introducing new technologies in critical areas.”

Reutech recently delivered the first (Movement and Surveying Radar) MSR 060 series in South America. The system was received by the local distributor CLONSA, and is being demonstrated to a number of prominent clients mining in the Andean region prior to delivery to the first client.  Reutech says “the highly mobile and adaptable modular MSR 060 series affords the user the option to customise their optimum solution for their specific conditions. The compact MSR 060 with its operating range of up to 600 m is ideally suited for mines which require close-range observations with critical real-time monitoring.

“When fitted to the back of a vehicle, the high mobility combined with the reliability and accuracy of MSR technology will allow this model to fill an essential requirement, indicated by various mining set-ups globally. The system is extremely robust and a valuable addition to the existing MSR series.  With these new specifications as well as a plethora of customisable options, the MSR 060 still has all the features, functionality and high reliability that the global Reutech Mining family has grown accustomed to.”

The MSR product range is designed to operate in harsh mining environments. The systems provide highly accurate, real-time, all weather surveying and slope movement measurements using state-of-the-art radar and surveying technology.  Measurements are fully geo-referenced to an accuracy that allows seamless integration with standard Digital Terrain Mapping (DTM) tools.  The simultaneous execution of stability and surveying measurements, combined with the high-speed external data links for remote operation, and extremely high reliability, makes the MSR range of products extremely useful as an essential real-time mining safety, planning and productivity improvement tool.

Elexon Mining, a world leader in tracking ore movement in underground mining, is now exploring a next-generation of Networked Smart Markers that has potential to be used in open pit mining, to measure in-ground deformation in slopes.  Elexon says: “Currently, available systems do not give the full picture of what is happening in the depth of the walls in an open pit mine, which is where structural failures could be developing. Elexon’s new solution will target inground deformation monitoring with the Networked Smart Marker System. This solution will enable open pit mines to achieve greater control over slope stability, and therefore mine in a safer and more efficient manner.”

For many years DMT has contributed significantly to geodetic, geotechnical and geophysical monitoring in hazardous environments through its numerous geomonitoring projects. To process and analyse the extensive measurement data from various measuring instruments and sensors, the company has developed a hardware and software solution which stores and analyses all gathered data in such a way that it’s available for sharing.

DMT SAFEGUARD is a modular system for safe and reliable risk assessment of slope stability in mining as well as the monitoring of subsidence and sinkholes in former mining areas. It includes the following functions:

• Data collection (data port module): Integration of heterogeneous data from a variety of sources (geodesy, geophysics,geotechnical engineering, hydrology, integration of image and video data)
• Data management (core server module): Central database on high-performance servers for good data accessibility and security
• Data visualisation (web-view module):  Online user portal for data presentation with interactive web GIS maps 
• Document management
• Data analysis (evaluation & alarm module): Notification by SMS or e-mail, as well as on site signals.

“The data from the complex monitoring network is consistently merged, saved centrally and securely managed, while simultaneously displaying up-to-date results to numerous users via web-view”, says Project Manager Karsten Zimmermann. DMT SAFEGUARD is designed as a SaaS solution (software as a service). DMT says it “will gradually be enhanced with additional project-specific functions.”

Mine planning

Mine planners can now benefit from the newly released MineSight Atlas from Mintec. This is a complete package for manual scheduling and stockpile management. It provides a resourcebased, true calendar approach to scheduling, and manages all material movement and reclaim. It works with multiple block models and makes mine areas for open pit and underground mining easy to manage. It integrates seamlessly with MineSight 3D, MineSight Reserve and MineSight Haulage and has profound implications for both open pit and underground operations, the company reports.

“It has been two years in the making, but Atlas’s impact will be felt for far longer,” said Mintec Vice President-Technical, Glenn Wylde.  “There’s nothing else like it on the market.  Everything is new, and we’ve built it with functionality and usability in mind.” 

Mine planning engineers can use Atlas for the following:  Manual scheduling for short to long-term schedules; Resource-based scheduling; Multiple activity types; Calendar-based schedule with Gantt representation; Direct 3D design of polygons and solids.   Atlas has already made an impression on MineSight clients in previews at Mintec’s MineQuest seminar series.

“MineSight Atlas looks like a fantastic tool,” said Justin Watson of Australia’s Xstract Mining Consultants. “The culmination of a number of separate engineering tools into a single userfriendly package is a great enhancement.”

Abel Puerta of Peruvian company Hochschild Mining agrees. “Atlas seems to me like a necessity,” said Puerta. “Integrating the different parts … or programs into just one to make it more robust, reduces training time and makes the product more complete because you have all of those tools at your fingertips.”

MineSight clients interested in the new product can now shorten their learning curve with QuickStart MineSight Atlas, a streamlined approach to training. The service includes the following:

•  Training with Mintec data:  Leave with a workbook and data for future reference
•  One-on-One:  A session with a MineSight expert, using your data to develop a tangible model that you can continue to build post QuickStart
•  Follow ups:  Mintec will guide you through additional workflows and make sure Atlas is delivering early results on site.

Pit optimisation

At Austmine 2013 in May, Gavin Yeates, Vice President Mine Optimisation, Group Resource and Business Optimisation, spoke about BHP Billiton’s Next Generation Mining (NGM). He explained the visions is that “our large open-pit mining assets, will be running standard processes and systems for production management (drill-hole to port), utilising autonomous mining equipment, operated from integrated remote operations centres, using the most efficient mining methods.”

Caterpillar automated mining trucks are arriving in Western Australia, with six of Fortescue Metals Group’s first 12 793Fs delivered to the Solomon mine and 12 trucks set to arrive at BHP Billiton’s (BHPB) new Jimblebar iron ore mine.

Yeates says autonomy will lift productivity through, higher utilisation, reduction of labour, greater predictability and less variability. BHPB has had autonomous haul trucks operating at New Mexico Coal for two years. Jimblebar commenced in August 2013 with six such trucks and is moving to a fleet of 12 trucks in 2014.

He also discussed Mass Mining Methods – “designing our mines for scalability and simplicity by identifying alternate mining methods for our large open pit operations.” The opportunities include increasing mining intensity by removing bottlenecks and haulage congestion. Reduce overburden with fewer ramps. Such planning will also reduce energy consumption.  The approach is to use fully mobile crushers and conveyors, gravity-convey technology, and under-pit infrastructure.

Like Rio Tinto, BHPB has a remote operations centre in Perth, Western Australia. The Iron Ore Integrated Remote Operations Centre (IROC) provides real-time management of the supply chain (pit to port) to reduce supply chain variability. Optimised scheduling (production and maintenance) is improving productivity. Colocation of controllers, schedulers and planners improves collaboration, decision making and  role consolidation.

Yeates’s key messages were that BHPB is “striving for a step change in productivity through the systematic introduction of autonomy, remote operations, and standard processes and systems.” It is “replicating technology implementations across our organisation (made possible by our common organisation design, processes and systems).”  This enables “a planned, controlled and safe work environment for our people.

“Why are we doing it?:

• Higher productivity to be achieved through better planning, compliance to plan and transparency of performance
• Reduced operating variability, higher proportion of planned work leads to safer work.”

Also at the Austmine meeting John McGagh, Rio Tinto’s Head of Technology and Innovation, explained that Rio is “in the process of deploying the world’s largest autonomous haulage platform. We have two mines operating today on the autonomous haulage platform and will commission a third before the end of 2013.

“We have moved 100 Mt with our autonomous haul fleets since we started the trials in late 2008, in addition close to 300 operational people have been trained on the technology. At current rates we should move our next 100 Mt during Q4 2014, depending upon new mine commissioning schedule this could be much sooner.

From its purpose built operations centre located adjacent to Perth Airport Rio operates some 14 mines, all rail and port infrastructure plus power and water distribution systems.

“Rio Tinto Iron Ore now possess unsurpassed experience on how to operate this type of facility. We have not rested on our laurels with the operations centre, we have turned our minds to increasing the efficiency and productivity that we can gain from these facilities, importantly, we have built into our operations centre many of the philosophies of human systems engineering.

“We believe the next generation of operations centre efficiencies will come from the seamless integration of the people who oversee and command these facilities with innovative systems design that makes the human interaction seamless. Our operations centre experience is going from strength to strength providing a capability that grows to support our expanding business needs.”

McGagh then introduced Rio Tinto’s new excellence centre. “The excellence centre facility went live this year and we are now able to interconnect, in near real-time, operational data on from large complex facilities; using this we model, analyse and optimise the performance of chosen processes irrespective of where they are situated anywhere on the globe.

“The excellence centre brings together hundreds if not thousands of man years of discrete process expertise by way of embedded computer models; it houses experts into one place and links these assets with the operations in real-time. It is also a critical training engine for our technical people.”

Another Austmine speaker was Mark Rexin, Production Systems Manager, Leighton Contractors, who discussed his company’s use of iVolve technology to gather real-time data. He recommended talking to “all levels of your team to find out what they really want and determine what they really need. Try your best to deliver both.”

Leighton has established real-time dig rate feedback in supervisor vehicles. This uses a Trimble Supervisor Tablet or ruggedised PC, with several iVolve dashboards to choose from. The system allows supervisors to see true rates based upon truck weights. One Senior Supervisor commented: “It’s great to be able to see the real time dig rates and be able to change the digging area, dig procedure, or process and watch the result that you have just implemented.”

Recovering the satellites

Neptec Technologies, a spin-out of Neptec Design Group, an award-winning space flight technology company and NASA Prime Contractor, has introduced its new OPAL-360 series of obscurant-penetrating 3D laser scanners to the industry.

“OPAL-360 represents the first step in Neptec’s broader strategy to adapt over 20 years of technology innovation for clients such as NASA and the Canadian Space Agency for commercial use on Earth,” said Paul Nephin, Chairman and Founder of Neptec. “It clearly demonstrates the value of government investment in space innovations that can be adapted successfully to commercial markets such as mining.”

Neptec Technologies says “its rugged, multipurpose 360 LiDar sensors are uniquely suited for autonomous off-road vehicles and robotics applications in harsh environments, as well as more conventional survey, mapping and monitoring tasks. Unlike conventional laser scanners, OPAL scanners can see through obscurants such as dust, smoke or fog and are packaged to withstand the physical abuse they will be subjected to in applications in mining.”

The OPAL-360 is environmentally sealed (IP67) with no externally moving parts, has a – 40 to +65 degree (celcius) operating temperature range, and is ruggedised to withstand significant vibration and shock levels. “It delivers an unprecedented combination of range, data density, acquisition  speed and obscurant penetrating capability.  Different versions in the OPAL-360 series support ranges of 400 m out to 3 km at accuracies of 1 cm and data acquisition rates of up to 200,000 points/s.

In real-time applications such as autonomous navigation or monitoring, it’s not about collecting and processing millions of data points per second but about collecting the right amount of 3D data that contains the actionable information you really need.

The company says “OPAL sensors collect 3D data in 360o in seconds using a unique, nonoverlapping scan pattern and can adjust the amount of data being collected in real-time under software control – from sparse to high resolution – without relying on vehicle movement to fill in those ‘data gaps’. They are compatible with Neptec’s 3DRi (3D Real-time intelligence) software toolkit, which includes ‘out-of-the-box’ features such as automatic change detection, automatic scan alignment, and object recognition and tracking. OPAL and 3DRi products make it easy to integrate optimised 3D machine vision solutions and reduce development and life cycle costs.”

Mike Sekerka, Chief Operating Officer at Neptec Technologies consider full machine automation to be the long-term goal in mining, but “there are many immediate opportunities to improve safety and productivity with intelligent 3D vision applications that assist the operator and reduce workload. We’re already working with clients in the mining sector to define such applications for excavators and haul trucks using our OPAL and 3DRi ‘building blocks’ to provide practical solutions for the industry.”

Dave Goddard, Portfolio Manager, Intelligent Machine Solutions, Leica Geosystems Mining explains that the satellite problem with machine guidance systems that require high precision GNSS positioning to provide robust 3D positioning is being solved. The problem is that the machines need at least four satellites and good DOP (Dilution of Precision) for X, Y, Z axes resolution and time. Augmentation systems can solve the problem. Leica Geosystems has partnered with Locata to deliver augmentation products exclusively to the mining industry to at least October 2014.

Locata has invented a ground-breaking radio positioning system that is equivalent to a GNSS positioning constellation but is ground-based instead of satellite-based. It is believed to be the world’s first radiolocation technology which replicates GPS in a ‘local’, rather than a ‘global’, area and has been granted 94 patents around Locata’s core IP – TimeLoc™. This allows localarea ultra high-precision time synchronisation of LocataLite transceivers to within ±3 nanoseconds.

This delivers a new and previously unattainable level of positioning reliability in areas where GNSS-only positioning is unreliable, Goddard explains. This has resulted in improvements from 75.3% to 98.7% in availability over a GNSS-only systems (maintaining RTK accuracy).

So, LocataLite networks are established in areas with GPS availability issues. The signals must be line of sight, so the shape of the pit needs to be considered, and edge obstructions avoided. The LocataLites need to be above the receivers. 

Leica’s Jps receiver is the world’s first GNSS and Locata rover. The system was described in detail in IM, September 2012, pp68-79.  One result has been a 6.5% improvement in daily drill positioning daily (almost an extra two hours). In two months on two drills, this equated to 4.7 days or nearly 113 hours of additional guidance – worth a lot of operating profit.  One of Goddard’s conclusions is that Leica Jps “has tremendous potential to improve positioning availability and safety for autonomous vehicles, during solar storms, etc.”

Thiess and Automated Positioning Systems (APS) say they “have set a new world standard for machine guidance system application, working together to place one of the most advanced GNSS based Machine Guidance Systems available on one of the world’s largest hydraulic excavators, the Leibherr 9800, at Thiess’ Lake Vermont operations in Queensland, Australia.

Thiess worked with Leibherr to develop the 9800 hydraulic excavator to further improve its production capabilities.  “Thiess has been working with APS solutions on a number of our Australian mine sites. We first used APS software guidance systems in 2003 on machines at our Collinsville mine operations and since then its sophistication has evolved significantly.  When we collaborated with Leibherr to develop the 9800 to meet our production needs, we knew the APS mineAPS™ Excavator system was the best guidance solution for it,” explains Michael Wright, Executive General Manager Australian Mining, Thiess.

APS develops its systems to be both flexible and scalable, ensuring they are providing the next generation of mine operations and production management solutions. The open configuration of the mineAPS Excavator system installed on the 9800 ensured the exact geometry of the machine could be put into the mineAPS software, enabling accurate modelling of the machine. The high precision capabilities of the system provide improved mining productivity through accurate measurement of the bucket position relative to the target cutting point. The movement and exact position of the excavator and bucket is made visible to the operator via a high quality LCD screen. The safety of the operator is also increased with the built in Proximity Warnings and Fixed Hazard Warnings, vastly improving the situational awareness. The current operator activity, machine status and the geo location of the machine is visible to site manager or supervisor for better management of the machine utilisation.

“The application is a great example of the scalability of our mineAPS systems to new machines types and sizes. We strive to ensure our systems and our support are second to none and we will continue developing our solutions to take mine operations and production management to the next level,” explains Dush Wimal, CEO, APS.

Traffic control

SolarOne designs and manufactures sustainable safety guidance systems that are used to delineate haul roads to minimise the risk of collisions. The original request for the products came from BHP Billiton for its West Australian open-pit mines.  SolarOne eliminates safety and health issues to do with the recent needs of some open pits to operate after dark to help raise productivity.  Those mines are characterised by their remoteness, extreme temperatures, presence of toxic chemicals and, often, stressful operating conditions, such that roadways that are continually being recreated. So, it is difficult to provide safety guidance, or delineation, particularly using conventional technology.

The result is FrontLiner and SolarOne’s Hugh Mitchell explains “the issues that we sought to overcome include durability, functionality, sustainability and reliability. To meet these challenges, the core-technology uses highly efficient, easily installed, industrial quality, photovoltaic-sustained, high-power LED, encased in extremely durable, advanced nylon plastic housingthat are so tough that they are unbreakable with a sledge hammer. Super capacitors that outlast batteries by many years result in a product that requires virtually zero maintenance for over ten years. The lights are visible for over 500 m from a 5 m high ore carrier’s cabin and format and functionality are selected to suit the placement indicating; hazards, roadway conditions and roadway directions.

There was a trial of the SAFEmine traffic awareness and collision avoidance system on surface mining machines and light vehicles at Teck’s Line Creek Operations in British Columbia in 2012. A six-week trial was designed to evaluate the effectiveness of SAFEmine in increasing traffic safety. Online real-time tracking of vehicles along with vehicle status reports were also demonstrated. Data was analysed regarding alarms associated with speeding, close vehicle interactions and potential collisions. The performance of customised alarming schemes for specific interactions, e.g., trucks with loaders, was also analysed.

Teck’s feedback, reported by Tarn Medinski, Teck ART (Applied Research and Technology) Engineer at the Haulage and Loading 2013 conference, Phoenix, May 2013:

• Useful tool to increase operator awareness in poor weather, at night, or in the fog
• Operators found SAFEmine was very helpful in keeping track of light vehicles around heavy equipment
• Speeding events were drastically reduced due to SAFEmine speeding alarms
• Early training and operator involvement is essential and a strong site commitment is needed.

  

In the same presentation, Todd Ruff, Business Development manager – North America, SAFEmine Technology USA reported:

• Extremely importatn to minimise nuisance alarms –intelligent alarming based on context and risk is critical
• Dynamic safety zones based on vehicle speed and type further limit alarms to just those that require action
• Operators will change their driving behavour to avoid dangerous situations
• Real-time tracking and reporting increases value
• Trial was successful and an additional trial is in progress at Teck’s Carmen de Andacollo mine in Chile.

With more than 15,000 units installed worldwide in more than 45 mines, “SAFEmine’s traffic awareness and collision avoidance system has become a standard as one of the best proven,” says the company’s Peter Stegmaier.  SAFEmine uses GPS to determine vehicle location, speed and direction of travel and broadcasts this information to other nearby vehicles to increase operator awareness of nearby traffic and potential collisions. It can also operate boom gates and features further options such as voice annunciations, obstacle and overhead power line warnings, and operator identification.

“Recently concluded large sales include Albian Oil Sands in Canada, Samarco in Brasil, and Mina Sur in Chile, with major trials underway at large coal, iron ore, gold, and diamond mines, leveraging SAFEmine’s local support in many countries.”

At Premier coal mine in Australia where the SAFEmine traffic awareness system has been installed for more than four years, Dean McAllister, Maintenance Superintendent said: “Premier had a more than 50% reduction in metal-to metal contacts within the year following SAFEmine full implementation.” Moreover, McAllister said that the operators trust the system, the maintenance team has found it to be reliable, and the technology has not caused any downtime.

One of the challenges seen in the modern cab involves the number of displays and alarm sources that require the attention of the operator. At Haulage and Loading 2013, Todd Ruff of SAFEmine USA also described the SafetyCentre System (SCS) that integrates multiple safety technologies into a single, simplified operator interface, de-cluttering the cabin.

A single touchscreen colour monitor displays a top view of all surrounding equipment locations with respective identifiers. Multiple camera views are displayed and automatically selected based on direction of motion. Radar detection alarms are digitally integrated into the top view display and on the corresponding camera view and indicate the area where detection occurred. The SCS can also detect motion on camera images. This development has been a co-operation with Kumba Iron Ore’s Sishen mine and Trysome in South Africa and is currently being rolled out on more than 300 haul trucks and 25 shovels at Sishen and Albian Sands, with further mines trialling the SCS.

Fatigue management

The area of fatigue detection and management has become increasingly important as research suggests more than 30% of road fatalities are caused by fatigue, and some reports have suggested fatigue causes more incidents than alcohol. SAFEmine also offers a Personnel Protection System which has shown very good results in a trial of a major tyre handling company and is now being rolled out.

SAFEmine is currently testing a predictive fatigue monitoring system which is based on multiple technologies featuring live estimation of an individual fatigue score and integrates with SAFEmine installations into a traffic safety system with consistent interfaces – for the operators in the vehicles as well as in the control room. This Fatigue Monitoring system works on three levels:

• Continuous reporting on overall fatigue situation
• Individual operator fatigue score in control room and on in-cab display
• Alerts in control room, in cab, through text message (SMS).

  

Guardvant’s John Capehart explains that the mining industry has “become much more focused on the issue of fatigue.” Consideration is being given to the problems of 12 hour, rotating shifts; working against the Circadian Rhythm and significant commute times to remote locations.

Guardvant’s operator fatigue monitoring and collision avoidance systems uses advanced technologies to help improve operator performance, create a more productive working environment, and protect assets. The company adopts a customer-centric approach to deliver operator fatigue monitoring and collision avoidance systems for specific applications.

OpGuard is a non-intrusive operator fatigue and distracted driver monitoring system that can integrate with ProxGuard, a collision avoidance system that uses radar, cameras, and GPS for proximity awareness and object detection.  Integrating OpGuard and ProxGuard addresses two leading causes of accidents: operator fatigue and blind spots.

Both systems can be integrated on a reliable, multi-functional mobile hardware platform which can accommodate other mining technologies, such as fleet management or equipment health monitoring.  SecurityGuard is security monitoring network with remote access and alerts. All three can be combined for comprehensive safety and security solutions.

In the case of mobile equipment, he suggests watching for bent ladders, scraped paint, broken mirrors and cut tyres – they can be strong signs of the results of fatigue.  In southern Africa, he says, “GuardVant has just installed the first ever integrated fatigue monitoring and proximity detection system.” It features:

• OpGuard – operator fatigue and distraction monitoring
• ProxGuard – proximity awareness and object detection
• Central analytics server with common systems database

  

The Guardvant Mobile Server (GMS) – onboard computer – supports OpGuard, ProxGuard and pulls in data from other applications, like machine health, biometric systems and fire suppression systems.  Capehart summarises:

• Fatigue is a major safety and performance issue
• Symptoms of fatigue manifest themselves in many forms: drowsiness, slow reaction times, inability to evaluate risk
• Academic sleep research shows strong relationship between fatigue and performance
• Guardvant has developed technology to assist drivers with both fatigue and proximity
• Technology has the ability to record in a single database the events for both fatigue and proximity and determine correlation.

Optalert recently received validation for its real-time operator alertness monitoring system by academics from one of the most prestigious research institutions, Harvard in the US.  Optalert CEO Scott Coles said Professor Czeisler of Harvard Medical School was part of a cross-institutional study concluding the Optalert fatigue detection product as setting the ‘gold standard’ in early fatigue detection – a key component of workplace safety.

“Recognition as holding the ‘gold standard’ in safety is an extremely significant reference,” Coles said. “The term goes beyond recognising we are worldclass, and asserts our wearable technology products as setting the benchmark for early fatigue detection and risk reduction. This then translates into real benefits for the many places in which we are currently operating across the world.”

Optalert’s fatigue detection products have been developed with more than 20 years of research by a team including current General Manager of Scientific Research Dr Andrew Tucker. Tucker said over the years the team developed new methods of measuring eye and eyelid movements. This then led to the world’s first validated scale of drowsiness – the Johns Drowsiness Scale – after Optalert founder and Chief Scientist Dr Murray Johns.

“From there we developed products to measure an operator’s fatigue levels in real time with the levels provided immediately to operators and their supervisor. This information enabled both the operator and supervisor to simply determine if their fatigue posed a potential risk to their safety and the safety of others,” Tucker said. “We are now on version eight of the product, and our results combined with the recent academic validation, demonstrating drowsiness can be predicted by ocular movements, means the Optalert product is the only scientifically-proven real-time alertness monitoring system.”

Tucker said while the academic validation was reassuring, the results out in the field of the many companies in which their products had been installed were most fulfilling. “We are thrilled with the results we have received from the constant flow of incoming data we are obtaining from work sites all over the world. Not only are we helping prevent fatigue-related incidents but we are also effecting real behavioural change in our operators. Once operators see the daily information about their fatigue levels, it has been shown they are becoming more alert over time, meaning they are better managing their fatigue levels.”

The full Harvard research paper about Optalert will appear in an upcoming issue of the Journal of Clinical Sleep Medicine and can be found at http://www.aasmnet.org/jcsm/AcceptedPapers

Rhonda Locke, General Manager Marketing, explains that Optalert “also provides fatigue management and education advice based on the most solid set of data you could imagine. Indeed a number of customers have changed their shift allocation and rostering systems based on the results of our 24 hour global data collection which provides a detailed analysis of each driver and operator who has been using the Optalert technology.”

Seeing Machines has signed a strategic agreement with Caterpillar Global Mining for DSS in-cab Fatigue Monitoring Systems for use in mining machines. The agreement covers a multiple-phase approach that commences with a supply and support agreement of the systems through the global Cat® dealer network and progresses to further phases that include joint product development and technology licensing agreements.

Rio Tinto’s focus on managing fatigue has led to truck drivers at Coal & Allied’s Hunter Valley coal operations wearing an innovative hi-tech cap to better manage their fatigue levels and reduce the risk of accidents.  The SmartCap looks like a standard cap but holds sensors across the wearer’s forehead to monitor signs of fatigue and assess their level of alertness (IM, April 2013, p76).  Hunter Valley Operations General Manager Operations Tom Lukeman said: “Safety is our number one focus and we’re excited about using an innovative technology like SmartCap to continue making our workplace safer. Fatigue is one of the main factors in accidents involving heavy mobile equipment, so SmartCap will help to make sure our workers go home safe and healthy to their families and friends at the end of each shift. Providing operators with real time information on their alertness levels allows them to better understand and manage their own fatigue.

“The operator is notified if their fatigue levels begin to rise so they can stop for a break or take other steps like moving to a different task or using the fatigue hut, a purpose built sleep room. An alarm is sounded in the operator’s cabin if they get to the point of sustained tiredness or are at risk of a micro-sleep. As a final precaution, in the event the operator’s fatigue levels continue to rise an alarm is then sent to the mine’s dispatch centre so that supervisors can intervene.

“The decision to use SmartCap was made after a successful trial at Hunter Valley last year which involved 48 operators and captured more than 4,200 hours of data. SmartCap adds to a number of fatigue management measures we have on site including soft controls such as diet, healthy lifestyle and training.”

Hunter Valley Operator Anne-Marie Henry said: “SmartCap is a great use of technology that helps people understand personal fatigue.  It is difficult to assess your own fatigue levels but SmartCap allows me to work out different techniques over the shift changes to help reduce my fatigue risk to both myself and others.  Since using SmartCap my fatigue levels have decreased as I am proactively trying to change the way I do things. I have more energy now during dayshifts which is where I struggle most with fatigue. This user-friendly tool helps me to reduce my fatigue risk and improves safety on site.”

Surface miners

Surface miners cut, crush and sometimes load rock in a single operation – a single machine completes the job of various different pieces of equipment. Drilling and blasting is not required.  Vermeer’s Mark Cooper points out that his machines do not load – “Loading is more efficient as a secondary operation.  With that being said, surface miners have a very bright future. They have the potential for autonomous mining.

Vermeer is on a product development path heading toward autonomous surface miners.  Surface miners produce a consistent, predictable uniform product size that is required for autonomous mining. Vermeer will be releasing new features each year for our products that will add value as standalone products, but when put together as a complete package will have the ability to create an autonomous mining machine.”

Additional primary crushing is eliminated. The material can be either directly loaded (only some machines) onto trucks via a conveyor system or, alternatively, deposited as a windrow right behind the machine.

The cutting depth of the surface miners can be adjusted to allow thin seams of material to be mined selectively and with a high degree of purity, thus maximising recovery of a deposit. AMC Mining Consultants noted in last month’s Advancing Australia article surface miner technology is particularly applicable to semi-hard material—where the ore lenses are thin and conventional excavation methods result in excessive dilution—and to flat lying orebodies.

Last year Fortescue Metals Group took delivery of 14 Vermeer® Terrain Leveler® surface excavation machines (SEMs) to be used in Fortesque’s vast iron ore mining operation in Western Australia.  Vermeer said at the time of the order that its SEMs allow mines to use precision surface mining — “meaning mine operators can selectively extract mineral seams. Operators can also control material sizing — producing small-sized material in a uniform configuration so minerals can be handled more efficiently than product produced by drilling and blasting.  The uniform product size allows more efficient settings on secondary and tertiary crushing systems; savings that can continue well past the primary crushing stage.”

Shenhua Beidian Energy became a shining example in China for the environmentally friendly mining of coal using surface miners. “We have been very interested in the innovative surface mining technology right from the start. What convinced us in the end was a visit to coal mines in India that were operated solely by means of surface miners. We were very impressed by the efficiency of the machines,” said Mr Liu, President of Shenhua Beidian Shengli Energy Branch.

A Wirtgen 2200 SM equipped with a 3.80 m wide cutting drum has been a great success in the Shenhua mine, demonstrating very ably, how highquality material can be mined without the environmental stress of drilling and blasting operations.  The 2200 SM has been in operation in the Shenhua mine since the spring of 2009. It is cutting coal seams up to 250 mm thick. The cut material is deposited as a windrow behind the machine and once the machine has moved onto another mining area, the coal cut in the first is loaded onto trucks by wheel loaders.

More than 150 Wirtgen type 2200 SM miners are in operation around the world. The standard 2200 SM model is equipped with a 2.20 m wide cutting drum. The optionally available 3.80 m cutting drum enables productivity rates in soft rock to be increased significantly.  Some 40 of the 2200 SM miners currently in operation are fitted with the 3.80 m drum. The Shenhua example cuts up to 5,000 t of coal in an eighthour shift. A 1,500-litre fuel tank enables operating times to be maximised while keeping breaks in operation as brief as possible. In addition, the miner has been designed so as to minimise the time required for maintenance procedures. Vital machine components, such as the cutting drum, are readily accessible, allowing the quick replacement of wear parts, such as the cutting tools.

Conveyors advance

As noted on Sandvik’s new website Minestories.com, Craig Wheeler, Associate Professor in the School of Engineering at the University of Newcastle in Australia, sees a growing future for conveyors. He began a career with BHP Billiton in 1989 as a cadet mechanical engineer and earned extensive belt conveying experience working in maintenance, operations and design positions at BHP’s Newcastle steelworks for more than a decade and says “the scales of new mining operations are resulting in unprecedented demands for greater haulage lengths, lifts and, of course, capacity.”

Today Sandvik designs, manufactures and installs complete conveyor systems in mining operations around the globe. “Many mines investigate how quickly they can introduce conveyors toreplace some of their expensive trucks,” Thomes Jabs, Vice President Product Lines, Sandvik Mining Systems, says. “We have a mine planning group to help operators determine at what point it becomes feasible to make the investment to replace trucks with conveyors.”

Important factors to consider include mine life, geology and deposit shape, scheduled material tonnage rates and the price of diesel fuel versus electricity.  “Every mass mining operation will eventually ask those questions, especially new mines,” Jabs says.

In addition to popular overland and in-plant systems, Sandvik offers innovative mine conveyors, compact-type conveyors, apron feeders and special conveyors that overcome differences in elevation.  Solutions for open pits also include semimobile, shiftable and fully mobile trackmounted systems tailored to operator needs.

Jabs also notes the ever-increasing popularity of in-pit crushing and conveying (IPCC), which IM covers extensively through its annual conference and regular articles.  “It’s an efficient way to move part of the processing plant into the mine, bringing it closer to the shovel, to the face, so that trucks don’t have to travel a long distance to a processing plant outside a mine,” he says. “Conveyors are an integral part of each IPCC system, and they’re the crucial link between primary crushers and spreaders.”

Today, single flight conveyors tens of kilometres long can move up to 20,000 t/h at speeds of more than 9 m/s.  Today’s intelligent conveyor designs drastically reduce friction and rolling energy losses. Optimised trough shapes and pronounced curvatures are now common. Higher-quality materials have improved operability and increased the life expectancies of today’s overland conveyors to more than 30 years in some cases, reducing capital and operating costs even further in new mines.

Wheeler says conveyor systems offer distinct advantages over truck haulage in efficiency and environment. “Belt conveyors being continuous, rather than a batch transportation system, are used wherever they are technically and economically feasible. With the demand for more and more automated mining operations, belt conveyors have clear advantages.”

Overland conveyors can be routed more directly than haulage roads and can effectively traverse grades of up to 20o, while haulage road systems are often limited to less than 5o.  Conveyors carry more material per hour, further and at higher speeds, increasing efficiency and reducing operating costs.

Conveyors also offer distinct environmental advantages over trucks. A conveyor belt in the average mine uses one-fifth as much energy as a heavy truck, reducing carbon dioxide emissions. Trucks burn diesel on empty return hauls, while conveyors haul material continuously. Conveyors are also quieter, generate less dust and occupy less land.  Each mine’s operational needs are unique, and Wheeler says different factors should be analysed to determine whether ore might best be transported using belt conveyors, trucks or a combination of the two.

Conveyors carry a high cost per metre, and many operations that lack fixed haulage distances will always require the mobility of trucks, he says. Some mines have learned to combine the flexibility of trucks conducting level haulage with the lower operating costs of conveyors for primary haul out of a pit.  “Choosing the appropriate bulk handling system depends on transportation distance, throughput and terrain, among other things,” Wheeler says. “Research has shown belt conveyors are generally more cost-effective on a life-cycle cost basis than both road and rail transport for throughputs up to 5 Mt/y over horizontal conveying distances up to 40 km.”

Pit mobility

Equipment mobility is crucial to squeezing that additional 1%-2% of productivity out of a mine operation. This is especially true with selective mining. Chris Friedel, International Sales Manager for TowHaul Corp explains that “nearly 200 TowHaul customers around the globe have achieved this mobility with a TowHaul Lowboy.”

“TowHaul pioneered the use of heavy-duty, off-road lowboys for mining more than 20 years ago and so the use of lowboys for improved equipment mobility is nothing new. However, the way lowboys are perceived today has changed greatly. Lowboys used to be seen as a ‘nice to have’ maintenance tool. In the last decade however, more and more clients report that their TowHaul lowboy is a priority one machine onsite for both production and maintenance. This distinction is backed up by the fact that numerous mines have more than one TowHaul lowboy and many are installing the equipment on lower hour and sometimes brand new trucks. Improved equipment availability is at the heart of this shift in perception.

“Equipment availability is the crucial aspect of productivity. Having the ability to move a machine from point A to point B in an efficient manner not only increases availability (and therefore productivity) but also reduces the wear and tear on the machine. Mining equipment is designed to move material, not commute.”

Equipment mobility is not just limited to moving tracked equipment on a lowboy.  TowHaul features a front loading lowboy that quickly and easily disconnects from the gooseneck so the unit can be used in multiple other configurations. The most popular of these configurations is the TowHaul TowHook Conversion Package, Friedel explains. With this option, mines are able to recover disabled haul trucks for transport back to the shop reducing traffic disruptions, field repairs and overall truck downtime. The gooseneck can be reconfigured for this task at the push of a button. The versatile TowHaul Gooseneck allows a mine operation to convert a single haul truck into a machine that accomplishes many critical onsite tasks safely and efficiently.

A front loading trailer itself is simple and effective. With this type of trailer, the full width of the lowboy rests on the ground while loading equipment, providing a wide and stable loading platform for heavy mining machinery, such as a blasthole drill. Coupled with the TowHaul Low Profile Front end, equipment loading is safe and secure while also taking into account the need to have as flat a surface as possible to avoid interference with the drill’s levelling jacks. The single axle design allows the lowboy to turn around in the middle of the haul road without ‘skidding’ the tyres.

TowHaul has introduced the first modular offroad lowboy for the industry, he claims. “Shipping costs are a factor when purchasing such a large piece of equipment, as are on-site erection times. The TowHaul Low Profile Modular lowboy eliminates the logistical concerns of getting a lowboy to site while keeping onsite erection times to a minimum. More recently, TowHaul has developed the ‘Oil Sands Configuration’, a lowboy trailer specifically designed to better handle the challenging conditions found in Alberta’s oil sands region.”

Specialist manufacturer Philippi-Hagenbuch offers lowboy trailers for moving large machines around large pits but warns that when considering such a purchase “it’s important to forecast what your mine site environment will look like in 15-20 years.  How large will the haul trucks be at that time? What’s the footprint of the mine and the approximate number of equipment you will have in your mobile fleet?  Below is a checklist of the top things to take into consideration when looking to purchase a lowboy trailer:

1. What is the maximum sized piece of equipment you may need to transport? Does this size differ when you forecast equipment sizes in the next 15-20 years?

2. How far will the longest haul be within the mine? (Make sure to take into consideration the size it will be in 15-20 years)

3. Will you be transporting tracked vehicles?

4. How does the loading of tracked vehicles on the lowboy trailer impact undercarriage maintenance?

5. How long does it take to load a piece of equipment and start the transport?

6.What modifications are needed to the prime mover?

7. What’s involved in the installation?

8. Which trailer will offer the most versatility, capacity and strength as well as the quickest return on investment?”

PHIL notes its new trailer has multiple patents pending, and “we believe it to be substantial enough to change the face of mining.” It features ultra-capacity rear loading.  The trailer gooseneck is firmly attached to the towing tractor, whereas during the loading process the trailer is firmly and positively anchored and does not pose a risk of sliding out from under a piece of equipment while being loaded.

The deck angles up as it moves forward towards the towing tractor, defining a very deep section which maximises the ‘beam’ strength of the trailer deck and minimises the lowboy trailer deck weight.

The axle up/down mechanism is locked in an ‘over centre’ position while in the transport mode. This technology enables the hydraulic cylinders to have no hydraulic pressure on them during transport, eliminating the concern about the hydraulic cylinders ‘drifting down’.

This trailer consists of two completely independent axles each with four tyres. Each axle arrangement will oscillate vertically independent of the other insuring uniform ground contact at all times by all eight trailer tyres. Trailer axles rise up (lowering the deck) and swing outward so that the trailer can be loaded.

The width of the lowboy trailer in the transport mode is substantially wider than either the trailer deck or the piece of equipment being transported, which results in much more stable and safe operation. (The width is typically considerably less than normal mine haul road widths).   IM