Anglo American Los Bronces

IM Editorial Director Paul Moore recently had the chance to visit Anglo American’s Los Bronces Integrated Remote Operations Centre in downtown Santiago, meeting with Cristobal Mimica, Autonomy Project Manager, Los Bronces along with Victoria Madrid-Salvador, IROC Superintendent and Andres Reyes, IROC Specialist.

The IROC was opened in April 2021 and takes up half of the 48th floor of part of the large Titanium Building. Andres Reyes told IM: “From here we are able to control the full value chain of the Los Bronces operation independently of any control rooms at the minesite. The IROC layout was designed according to the mine copper production process.” The IROC and the mine crews operate on the same four days on four days off work schedule, within which there are two daily 12 hour shifts.

Left to right: Cristobal Mimica, Autonomy Project Manager, Los Bronces; Andres Reyes IROC Specialist; Victoria Madrid-Salvador, IROC Superintendent and IM Editorial Director Paul Moore

The first stations are concerned with geotechnical monitoring and geology – the former measuring pit wall displacements and slope stability using radar and other technologies – at its highest there is over 1 km from the top of the operation to the bottom looking north to south. Next are the geology stations which perform several roles – but first and foremost managing sampling and grade control to manage the waste and ore block model at a short term and detailed level.

Next in line is the drill bay which carries out operation and control of five Epiroc Pit Viper 351 autonomous drills. Anglo American operates up to three drills per station, with teleoperation also possible. The controller makes sure drills are following the patterns correctly – these are multipass on double benches. It represents a huge improvement in the mining process in terms of efficiency and already there have been over two years of good results. The mine is also working on the incorporation of autonomy of the smaller Epiroc pre-split SmartROC drills – during the IM visit, the operator station for these drills was already established in anticipation of this function moving to the IROC by end-2023.

On to the load and haul processes; first up being the FMS specialists – the mine using the latest version of DISPATCH from Modular, and the team making sure the mine’s daily production plan is being fulfilled from an equipment scheduling, positioning, payload and availability point of view. Los Bronces also uses ProVision, Modular’s high precision machine guidance system for loading tools which helps to increase the total tonnes moved, improves the accuracy of material movement, and decreases costs associated with working outside of the mine plan.

Also in the area of the IROC is a controller to monitor the mine’s fatigue management system, which has been operating across the site since mid-2022. Victoria Madrid-Salvador told IM that Los Bronces chose to use the Optalert glasses-based iris-dilation monitoring system. This is integrated with the FMS, with any fatigue alerts then managed through that, such as switching that operator out of the shift early for a rest stop. Optalert was actually the worker union’s preference versus other systems based on in-cab cameras – Anglo American agreed to test the glasses, which was successful and led to a full rollout. Taking the workers opinions and inputs into account is crucial to get buy-in with these types of technologies.

On autonomous trucks, since the start of that project the controllers were positioned at the minesite as the first trucks were brought online in May 2022 and since that time a lot of training was taking place. As of mid-2023 the latest Frontrunner licence allows closer integration with the DISPATCH FMS – optimising the mixed AHS truck and manned truck fleet that is already operating. In time the Frontrunner controllers will then also move down to the IROC in Santiago to the same area as the FMS specialists.

Autonomous Komatsu 930E truck, Los Bronces

Next is the mine short interval control which a enables the mine to monitor key performance indicators (KPIs) in real-time for the daily 400,000 t of material mined (ore plus waste), with about 160,000 t/d going to one of two primary gyratory crushers. Madrid-Salvador says that the SIC lets the mine identify any issues quickly and make fast adjustments as needed, such as if there is an issue with throughput in one of the main SAG mills – the mills have an additional expert system.

Each crusher marks the start of two distinct production lines – one utilising the older Los Bronces mill which handles about 60,000 t/d and the other larger and newer Confluencia mill handling 100,000 t/d. The plants are about 7 km apart from each other, with Confluencia also about 500 m lower than the minesite – it received ore via a conveyor system that includes a 4.4 km tunnel. The plants still have their own control rooms but today these function more like a backup, so that primary control could be switched there in the event of an earthquake for example, if the IROC building had to be evacuated.

There have also been some unexpected wins as a result of remote operation. At the IROC start, meetings were held between the FMS dispatchers and the primary crusher operators. This coincided with a camera being set up at the crushers and has led to regular interaction between these two teams to a greater extent than before which has really boosted communication for example if you have loaded trucks queuing or a crusher delay due to oversize.

In the middle of the IROC is the central bay – this is an overview of the whole operation and seats the IROC Chief responsible for the overall running of the operation, supported by the mine planning and metallurgical supervisors either in person or remotely. Essentially the IROC Chief is looking to optimise the full copper value chain and achieve fine copper production targets – looking at trends, any problems or alerts and having the ability to go to any of 700 cameras across the operation. Communication low latency thanks to a new Nokia 4G LTE network has really improved the resolution and removed delays. Overall comms redundancy is provided by an optic fibre cable connection between the IROC and the mine.

What about return on investment? Clearly the IROC represents a huge safety and quality of life benefit for many workers and operators that no longer have to travel to the mine. But what tangible productivity improvements have been seen? Madrid-Salvador said: “A major improvement has been around solving communication problems – we are able to make decisions in a much more agile way – because many of the senior operators and managers are all in one place and not spread out across a huge minesite. This translates into greater efficiency which we have proven and measured. We have also seen much more consistency in stockpile levels, thanks to measurement from the IROC; and we are now able to work with less process plant water reserves due to the level of 24/7 supervision of water levels now in place.”

The IROC uses a near real time 3D model of the mine, which integrates a lot of other systems from dispatch to surveying to output planning. This model makes it possible to check compliance to plan as well as monitoring key KPIs. The mentioned stockpile LiDAR monitoring is an important part of this which using point clouds makes it possible to accurately estimate stockpile levels and volumes using six Ronin LiDARs to map the entire surface. The mine needs to have enough of a buffer tonnage to guarantee production. Before the system was installed, people had to estimate the stockpile levels using data from the conveyors combined with algorithms.

Then there is a complete model of the two milling plants including all key parameters – this functions almost like a digital twin with all of these processes almost monitored in real time. Lower grade ore is processed into cathodes at the minesite SX-EW plant close to Confluencia which accounts for about 10-15% of the mine’s fine copper production. For the high grade ore the IROC focus moves from the mine down the valley and the transport of ore slurry by pipeline 56 km to the Las Tortolas I and II flotation plants with the concentrates either sold to customers or processed into copper anode at Anglo American’s Chagres smelter. All the ore slurry pumping and flotation processes are also monitored at the IROC plus it has a tailings station to monitor the tailings dam operations at Las Tortolas.

Finally, the IROC has stations relating to operational support – notably power supply and the power grid – today this is all renewable power; as well as external water supply. This area of the IROC also includes the logistical teams tasked with the transport of the final products – mainly by truck – including cathodes, copper concentrates and anode copper. And the production accounting team to validate the finalised numbers for fine copper production.

Autonomy and innovation to the fore

Looking in more detail, both autonomous drilling and autonomous haulage are well established technologies at Los Bronces, but as at other mines the drivers and actual technology are quite mine specific. Cristobal Mimica told IM: “From our point of view in operations, what we are looking for is the precision of the process, which in drilling still depends a lot on the human factor. But before this depended on an operator in the cabin who is exposed to risk – they are often close to the highwall, or close to bench edges or ore faces. So to remove the operator from the cabin and put them in the IROC actually improves the utilisation of the fleet while also improving the quality of life of the operator – no exposure to noise, vibration or climate extremes like cold. But it is also more efficient – for example at site the operator has a one hour lunch break, but in addition to that time they come out of the cabin, travel for maybe 30 minutes to the canteen and then the same back again. So there is unavoidable underutilisation of the drill asset. Here, the autonomous drill operator still has a lunch break but eliminates all that site related extra time plus the climate extremes and high altitude of being at the site. Plus the machine continues to drill anyway during lunch breaks and shift changes.”

Anglo American is now also applying this principle to remote dozing at Los Bronces – while some remote dozing was carried out in the past – today it is becoming much more intensive because of the reality of the mine. The machines are using Caterpillar’s MineStar™ Command for Dozing. “In this case we are doing this for the same operational and safety reasons but also we have areas of the mine requiring this work that we are not able to access with personnel. Safety is non-negotiable – we had an incident at the end of 2021 where a dozer fell from the edge of a waste pile. We have also agreed with the Chilean authorities that no human operators will go into that area. With remote dozing as with the drills we can increase utilisation while maximising safety.”

Aside from drills and dozers, Anglo American is also looking at remote control shovel operation, where it is working closely with Komatsu as the machine intended for use is a PC7000 hydraulic excavator. This will load the Los Bronces autonomous Komatsu 930E trucks, which are already running on the Komatsu FrontRunner AHS. “The issue we have with this technology is that we will be one of the first commercial deployments so a lot of testing and trialling has to happen to prove it out – as we don’t have examples from other sites within Anglo American or even within mining to show learnings and experience.”

Komatsu is well advanced with testing at its Arizona Proving Ground (AZPG) and has released the software platform for operation of remote control shovels. However, the testing and software to date related to a face shovel – now at AZPG the boom configuration has been changed to a backhoe, which is what will be used at Los Bronces.

Remote control Komatsu PC7000 being testing at AZPG in Arizona

On the trucks, Los Bronces has 34 autonomous 930E trucks at last count – 28 of these were new trucks – and of these half came with sensors factory fitted, with the rest on top of this figure being retrofitted, in addition to the non-new machines. Los Bronces is very experienced with Komatsu trucks but there is an agreement in place where Komatsu provides support in terms of retrofit and maintenance of the AHS technology during the fleet ramp up phase. In terms of actual truck performance – the autonomous trucks at the mine are already exceeding manned figures, with any shortfalls more down to operational issues causing some lack of utilisation related to non-autonomous operations or equipment. Los Bronces also stands out in that it is already operating autonomous and manned trucks in a mixed fleet environment – one of a handful of mines that have achieved this.

“We are mixing the fleet as we need to introduce the autonomous trucks as fast as we can over time and also because we have quite a complex haulage circuit at the mine that would make it too difficult to be running two separate and distinct fleets. To get 100% autonomous we need 82 trucks to be converted so we still have a long way to go. Simply speaking, the way it is set up, the autonomous trucks recognise and treat the non-autonomous trucks as autonomous for the purposes of the system.”

The teams at Los Bronces and Quellaveco are also part of a knowledge sharing partnership protected by NDA between Anglo American and Teck, which has included visits to Highland Valley Copper, a Cat AHS mine and Elkview, which uses Komatsu AHS. “We share experiences and best practices, especially related to safety and reaching the maturity curve related to safety as soon as possible.”

In terms of training for autonomy, Los Bronces is a so called assisted operation – this includes some staff from Komatsu who are well experienced with the technology, and work with the Anglo American technical team – this technical team and the new Central Controllers from Anglo American who will ultimately manage the AHS fleet along with the Pit Patrollers out in the mine, who verify any obstacles that have caused one of the trucks to stop or slow down.

Los Bronces also has the unique position of being able to share experiences with the Quellaveco mine over in Peru, which operates the Cat Command for hauling system. And the El Sodado mine will be able to use learnings from Los Bronces when it comes to automate the fleet there.

And knowledge will flow the other ways – such as learnings from Coarse Particle Recovery using flotation at El Soldado being applied at Los Bronces. Los Bronces has also started up a bulk ore sorting project in the main part of the pit based on the set up at El Soldado which has been running for several years which in both cases use a grizzly, feeder, sizer, conveyors & associated equipment from MMD, used in conjunction with an ore scanning system equipped with scanners using PGNAA and/or PTFNA technology.

Of course the shovel operator also plays a key role in the AHS operations, and Los Bronces has a highly experienced shovel team, which has been further boosted by a retraining and continuous improvement approach and its ongoing P101 transformational asset productivity program. Shovel operations moved from 21 Mt/y to 37 Mt/y – achieved mainly through training and best practices. This focus on improvement has really helped in getting shovel operators ready to interact with the AHS trucks using an autonomous touch panel – such as calling in the trucks to their desired spot point for loading and then kicking out the truck at the end when loading is complete.

What about the potential for the nuGen™ zero emissions FCEV truck in Chile, which was developed by Anglo American and First Mode? It is widely accepted that ultimately, zero emissions trucks at a fleet scale will have to be autonomous anyway. “Everything is possible and is on the table. Certainly, hydrogen does look attractive for Chile and that is why there is a lot of focus on it here. We are going with automation first before zero emissions because the technology is ready and we can achieve the benefits quickly.”

Los Bronces Integrated Project

As a footnote, along with innovation in the open pit mine, in April 2023, Anglo American welcomed a decision in Chile by the Committee of Ministers to approve the environmental permit application for the Los Bronces Integrated Project (LBIP), setting up the next phase of development there. The underground mine ore will supply an extra 150,000 t/y of fine copper, with a $3.3 billion investment estimate – subject to a final Anglo American board approval.

Ruben Fernandes, Anglo American’s Regional Director of Americas, said: “We welcome the decision from the Committee of Ministers in support of our ongoing investment in Los Bronces – securing the long term future of one of the world’s largest copper mines. We have designed the Los Bronces Integrated Project as an example of the very best of modern mining, bringing not only investment and jobs, but extensive protection for the environment and a considerable improvement in air quality for the broader region of Santiago.”

LBIP is a multi-billion dollar project to develop the next phase of the existing open pit within Los Bronces’ operating site and replace future lower grade ore by accessing higher grade ore from a new underground section of the mine. The project uses the mine’s existing processing facilities, optimises water efficiency, has no impact on glaciers and requires no additional fresh water or tailings facilities.

The project will use sub-level open stoping, an established method globally such as at Boliden Garpenberg, MATSA Magdalena and various Sudbury area mines, with a lower ore extraction (50 to 70% of ore extracted) but with no surface impact.

The project comprises a new underground mining sector, 5 km southeast of the current pit under the north side of Yerba Loca, with operational continuity of the current open pit along with boosting the water recirculation system. It also entails replacing some ore currently extracted from the pit with higher-grade ore. Importantly, the underground Los Bronces mine will use cutting-edge technology including autonomous and electric underground vehicles, meaning lower risks for people and elimination of greenhouse gas emissions.