Chile’s mining explosives & blasting tech major Enaex is increasingly becoming a global player through ventures like its new explosives JV Enaex Africa with Sasol and its recent agreement to buy Downer Blasting Services in Australia. During the virtual MassMin 2020 conference opening day on December 9, Danko Morales, Enaex Manager, Underground Mining talked on Past, present and future of blasting technologies for Mass Mining.
One notable change in underground mining to which Enaex has responded has been the rapid replacement of manual charging using ANFO – the standard in Chilean mines for many years – with mechanised operations using pumpable emulsions. The mechanised pumping of the explosive charge has become an important area for development because it requires specialised equipment. Between 2000 and 2015, Enaex launched three key units for decreasing charging times: feeder trucks to feed UBT and UBS trucks with emulsion components; UBT trucks to charge emulsion in horizontal and downward blastholes and UBS trucks to charge emulsion in upward blastholes.
UBT trucks have been used in El Teniente since 2018 and in Chuquicamata underground mine since 2013. In the case of El Teniente, today there are eight UBT trucks for loading emulsion, replacing more than a century of ANFO usage. In the case of Chuquicamata’s underground operations (UG), these units have been utilised since the first tunnel development blasts. UBT trucks are equipped with an independent power supply and separate tanks to transport components; these can work for 12 continuous hours or more and permit the on-site gasification of the explosive.
UBS trucks are also present in Chuquicamata UG. In 2018, tests were carried out to evaluate the feasibility of a single-phase draw bell excavation. With these tests, theoretical assumptions about Particle Peak Velocity, Powder Factor and Explosive selection were adopted. Duoblast-V® was used as the explosive and the UBS Truck was used as the charging unit. Duoblast-V® features include high strength, good adherence and high velocity of detonation, while UBS truck features include full mechanisation and a telescopic boom to prime, load, and install the stemming, as well as separate tanks for component transport and independent power supply, like UBT trucks. The single-phase blasting tests were successfully carried out, and the know-how acquired during the study made it possible to consider gains such including the decrease on the number of drillholes, which also reduced total charging time and explosive consumption.
In 2018, Ubex One® trucks were launched in an effort to unify the charging process (pumping emulsion inside any direction blastholes). Ubex One® trucks are underground trucks with special bodyworks for holding emulsion components and also for on-site explosive manufacturing. Ubex One® trucks have the advantages of permitting remote control, emulsion preparation and loading by just two operators, and reducing the charging times up to 40% compared with conventional methods.
Since March 2019, Ubex One® Trucks have been working in Chuquicamata underground mine. These units participated in the first undercutting blasting on May 15 2019, and they have made it possible to incorporate at least 6,000 square metres of area per month. Up to early 2020, these units had actually achieved more than 9,000 square metres and 21 drawbells per month.
Enaex also provides preconditioning alternatives for dynamic weakening with explosives. This technique offers several advantages over hydraulic fracturing, for example, from the point of view of the resultant fragmentation. In 2017, Enaex introduced its family of products for preconditioning which include an Emulsion called Preblast® and a special unit for its manufacturing and loading called the Preblast® Truck. Preblast® has a velocity of detonation of 5,500 (m/s). It is water resistant, and its high hydraulic pressure resistance allows drillholes to be charged up to 200 m.
The Preblast® Truck is an underground truck similar to the Ubex One®, but it is adapted to load emulsions in very long holes, and it is also energy autonomous. This innovative pack of truck and product was successfully used in the Andina Río Blanco block cave mine in 2018. In that operation, the technology enabled total charging time to be reduced from two months to a few weeks and the undercutting process to be initiated earlier than expected.
Morales stated: “In the near future, Chilean underground mining will witness the massive application of emulsions or other water-based explosives to the blasting process. Also, all operations will be mechanised, and explosives will become completely on-site manufactured. After the massive application of water-based explosives, the industry’s next step will be the full automation of the rock blasting sequence, including priming, manufacturing, charging and initiation.”
This is important since rock blasting is the one activity in the development cycle that is still realised by manual procedures in many underground mines. In 2019, simulation studies were carried out to evaluate the potential performance of an autonomous charging process in an important block caving mine in central Chile. With the incorporation of autonomous equipment and emulsion, the hours of exposure for personnel could be reduced from more than 25,000 to zero, and six additional effective hours could be added to the available daily time. Given the number of metres to develop, autonomous charging would allow preparation time to be reduced from 90 to 82 months (10% less), and without interference it could be achieved in just 41 months (55% less).
Beyond the use of autonomous activities and emulsions, further developments in robotics are projected in underground mines in the short term. These advances will transform many high-risk human activities into more secure, remote, autonomous and robotised tasks says Enaex.
Moving to open pit mines, they have been able to increase production, and high capacity Manufacturing Trucks from different providers have been essential for this rising trend. In 2011, Enaex launched its modern units, Milodón® Trucks, which have the advantage of including pumping technologies and safety controls. Milodón® Trucks are currently in use in several Chilean open pit mines such as Collahuasi, Los Bronces, Chuquicamata (previous open pit), Andina Sur and Los Pelambres, and operations in other countries including Brazil in the Serrote mine and Peru in the Constancia mine. These trucks have allowed productivity to increase by 50% (due to their high capacity and pumping systems) while reducing the required personnel by 33%.
Safety has become the number one priority in the mining industry. Many risks are associated with zones that have difficult access. To manage this problem, Enaex has launched robotic solutions, which include RoboMiner®, Mine-iTruck® and Stemming-iTruck® which form a complete family of equipment for performing full remote blasting. RoboMiner® is a humanoid unit mounted on four wheels that can moor and prime the blastholes. Mine-iTruck® is a sophisticated truck, which can transport raw materials, manufacture explosives on-site, and load them. Stemming-iTruck® can plug the blastholes with gravel.
“Mine -iTruck® was first used in 2018 for the first teleoperated charging of ANFO in the world carried out in a large Chilean open pit mine. Mine-iTruck® together with Stemming-iTruck® and RoboMiner® were used for the first full remote blasting in mining history. Today, this package that includes the full set of robotic solutions is the only one of its kind in the market, and it is being successfully implemented in an important operation in northern Chile.”
“From the point of view of open pit mines, teleoperated, robotic and autonomous activities will increasingly define the future. Teleoperation and robotics are technologies already in use by Enaex, and they have helped gain access to places that are difficult and/or dangerous to reach. Since 2019, Enaex has demonstrated that complete teleoperated and robotised blasting is possible in open pit mines using RoboMiner®, Mine-iTruck® and Stemming-iTruck®. The next step will be to automate all activities.”
Today, Enaex units can drive alone, thanks to Mobius® software, which is part of the partnership between Enaex and ASI (Automated Solutions, Inc), but there are special tasks that still require remote control. As in underground mines, Enaex seeks to go further in open pit mining to achieve fully automated blasting in the short term.
Finally, new 4.0 technologies have spurred the fourth industrial revolution, and from the point of view of Enaex, these technologies are the means to add value for customers. However, Enaex knows that technology associated with a digital transformation is where the future lies.
In this context, Enaex has set itself a digital goal: “We are committed to being the preferred partner for our customers, supporting them in improving their businesses with digital solutions.”
In 2019, Enaex established its four strategic pillars in the framework of new technologies and digital transformation:
- Optimise the result required by the client through customised and value-added blasting services, using global and historic data
- Achieve digital integration with customers, connecting Enaex with their operations and thus supporting their processes to achieve operational excellence
- Humanise mining by reducing risk exposure and improving workers’ quality of life through the use of digital technologies
- Reduce variability in internal processes to improve the quality of service and customer experience
Enaex Bright®, one of the key digital projects of the company, is a digital platform of data management or “cloud” that will provide recommendations according to conditions. Enaex Bright® will use three steps to achieve this objective. First, Enaex Bright® will capture an enormous amount of data or Big Data. This will be realised thanks to on-site digitalisation, moving from paper notes to tablets and mobile units transmitting in real-time. Second, Enaex Bright® will use the Big Data for analysis and modelling through machine learning and artificial intelligence. Third, Enaex Bright® will deliver recommendations about blasting agent types, optimal mixtures and quantities when consulted regarding a new scenario or condition.
“Today, Enaex Bright® is working on step one. It is collecting information from manufacturing trucks, saving design data like blasting geometry and rock type, and also saving operational parameters such as quantities of explosive and depth of the drillholes.”