Showing Blasting’s Sustainability Value

Ralf Hennecke, BME, part of the Omnia Group, South Africa, details how blasting technology can help mines with their long-term contribution to sustainability.

With the mining sector’s long-term vision and focus on sustainability, the strategic contribution of electronic detonators and emulsion explosives in blasting is growing significantly.

The use of electronic detonators and emulsions have been instrumental in supporting the mining industry’s drive towards the mine of the future. In many ways, sustainability today is really the cornerstone of mining’s philosophy and operation. Blasting technology has been evolving in a similar direction to align with the key underlying priorities of customers, and to promote the sustainability agenda.

Emulsion explosives are now the dominant blasting medium in opencast mining in most parts of the world, and are finding their place increasingly in many underground applications also. There are many reasons for this, not least the ability to make mine sites safer and more efficient.

As a key aspect of overall commercial sustainability, safety has never been more important to a mine than it is now. Being inert until sensitised in the blast hole, emulsions provide high levels of safety and ease of transport – unlike Class 1 explosives.

Rather than safety being an added cost or obstacle to productivity, mining today increasingly recognises that safety underpins a streamlined and efficient operation. There is also a safety benefit beyond the mine, as emulsions cannot easily be used to create explosions by

those not authorised to do so. They are therefore less likely to be sought for illegal use, where lives may be placed in danger.

Cleaner explosives

Focusing first on the environmental benefits of emulsion explosives, there are several factors that stand out as the most obvious. This includes the fact, for example, that the dual salt emulsions pioneered by BME are less carbon-reactive, meaning formulations can be adapted to minimise the carbon fumes generated by the explosion. Another advantage is the incorporation of used oil as the fuel agent in emulsions, such as those in BME’s products; this disposes safely of used oil, which is a potential contaminant of water and soil if not responsibly managed.

Emulsions do not dissolve in water like ammonium nitrate/fuel oil (ANFO) does, so emulsions are much less likely to contaminate any water that they encounter. Emulsions also have a high energy factor, allowing for less product to be used to achieve the same rock breakout force.

Where emulsions really contribute to a sustainable environment, however, is in the way they reduce a mine’s downstream energy consumption – and hence its overall carbon footprint. Here, their value is enhanced by the role of electronic detonators and related digital technology.

Figure 1. Dual salt emulsions pioneered by BME are less carbon-reactive.

Figure 2. Blasts are carefully designed and timed to optimise rock fragmentation.

Electronics and energy

The evolution of electronic detonators has transformed the blasting process, making blast timing progressively more precise, reliable, and flexible. This allows blasts to be carefully designed and timed to optimise rock fragmentation – as well as to more clearly separate ore from waste – to make loading, comminution, and extraction functions more efficient. Emulsions themselves also contribute to blast flexibility through the ability to adjust their density, and hence the power they deliver at different levels of the blasthole.

Loading, hauling, crushing, and milling are among mines’ most energy-intensive phases. Therefore, achieving the right fragmentation during blasting means that less energy needs to be consumed downstream, which can have a significant positive impact on the cost of a mine’s energy, as well as its carbon emissions as a result.

There is also the potential for larger surface blasts, as electronic detonation systems facilitate ever larger numbers of detonators being used within a single blast sequence. During every blast, mines must clear all equipment from the blast area and halt operations, so the fewer the blasts, the better. By having fewer blast cycles, mines can reduce their downtime and improve their overall productivity and commercial sustainability.

Paving the digital path

An often-unrecognised aspect of the electronic trajectory of blasting technology is how it has contributed to the more general shift towards digital solutions in mining. Blast planning software, for instance, leverages the power of electronic detonators to be given a digital instruction to ignite at the precise moment required for optimal effect. Such software also allows for complex blast plans that consider the ore body’s detailed geology and the mine’s preferred blast outcomes.

These complex designs can be developed relatively quickly, due to the powerful capabilities of software such as BME’s BLASTMAPTM Surface and BLASTMAP Underground. These blasts can also be simulated before they are applied on the bench, allowing for various checks and improvements.

Much of the progress achieved in mining efficiency is related to the more effective gathering and utilisation of data. In blasting, this means that digital technology plays an important role not just before a blast, but also afterwards – in assessing how well a blast plan was translated into practical performance.

By monitoring more closely the way that on-mine functions are conducted – from blasting to mineral processing – the industry can better assess its performance, and make incremental improvements. Digital systems make for better data generation, collection and analysis, and electronic detonation systems allow mines to track and interrogate their blasts more accurately.

Such measurement techniques range from the real-time tracking of emulsion volumes being pumped into blast holes, to the use of drones, 3D photography, and global positioning

Figure 3. BME's AXXIS TitaniumTM system.

Advancing electronic blasting another step forward

BME recently launched AXXIS TitaniumTM, an advanced electronic blast detonation systems, which aims to raise the bar for safe and efficient blasting across the mining industry.

It is the latest generation of BME’s popular and AXXISTM system, which has achieved regular advances in blast performance, safety, and reliability.

The product builds on the achievements of the company’s AXXIS GIITM model, and improves many of the features that have served its customers well in the past. These include further refinements in safety, accuracy, flexibility, ease of use, and speed in preparing each blast.

Most importantly, the AXXIS Titanium system was built for the blaster and blast engineers who work with the product every day. The robustness of the wire used, the easy-to-use interface and the improved integration, will improve efficiency in terms of time, data, and reporting.

Safety remains the watchword with this new iteration, which incorporates a Swiss-designed application-specific integrated circuit (ASIC) chip in the BME detonators, delivering several added benefits. The ASIC provides the system with more internal safety gates against stray current and lightning, enhancing safety levels and allowing for inherently safe logging and testing.

A unique innovation utilised within the device is the use of dual capacitors and dual voltage, allowing operators to conduct low voltage logging to avoid any chance of detonation. AXXIS Titanium was developed to be resistant to electro-magnetic pulses (EMPs) caused by blasts, which can affect the accuracy of detonators or even cause them to fail.

The ASIC chip boasts more memory and processing speed, facilitating easier timing and centralised programming if the timing needs to be changed after being conducted on the bench. It also achieves lower power consumption with the incorporation of dual capacitors – so more detonators can be initiated per blast. The system can now manage 1000 detonators per blasting box and up to 20 blasting boxes can be linked and synchronised through hard wiring, enabling the possibility of initiating up to 20 000 electronic detonators in a single blast – doubling the capacity of the AXXIS GII generation. systems to profile blast results. The data lends itself to ongoing cost optimisation, and to ensuring that there is no wasting of resources in achieving the optimal blast result. The volume of emulsions used are easily tracked by on-vehicle equipment; for instance, BME’s smart trucks transmit this data through wireless platforms, enhancing the traceability of product.

The closer control that electronic and digital technologies provide to the outcome of a blast has implications beyond the mine and the blast site. The social environment beyond the mine, and even nearby infrastructure, is better protected when aspects such as vibration, dust, and fly-rock can be better controlled.

Going underground

The benefits of emulsions and electronic detonators have so far been reaped mainly by the opencast sector, due to the considerations of volumes and economies of scale. The relatively larger and deeper blast holes drilled for surface mining, for instance, enhances the cost savings achieved in the volumes of emulsion pumped. However, underground mines are increasingly shifting away from ANFO and cartridge explosives, especially where massive mining methods are used.

Using an emulsion explosive in an underground environment improves safety, as it is not a Class 1 explosive demanding special handling procedures. However, its value extends beyond safety; with the right infrastructure, it can help streamline the whole mining operation.

This infrastructure is based on a dedicated closed-loop system for transporting emulsion from the surface to the underground workings, and has already been successfully applied in South Africa and elsewhere. A vertical pipeline transfers the emulsion directly from the surface, so it does not take up any shaft time. It can then be stored underground and transported to the face as required.

Digital integration

To realise their sustainability goals, mining companies are reporting more intensively on all aspects of their operations. At site level, the focus is on efficiency and transparency – so that management can intervene where both commercial and sustainability improvements can be made. This means that all service providers and technology partners must ensure that their technical, monitoring, and data systems speak to the digital platforms chosen by the mine. Only in this way can the large volume of data streaming in from every aspect of the operation be clearly represented and analysed.

This applies as much to the blasting function as it does to milling efficiency and mineral recovery. All blasting indicators therefore need to be digitised and, as far as possible, automated. This requires a growing depth of expertise in the digital space among suppliers to integrate their own technological offerings with each other, as well as with those of the mine.

In conclusion, digital capability is now a core requirement among mining supply partners – ensuring that all solutions provided can be integrated seamlessly with a customer’s own platforms. It is essential to enabling mines to monitor, control, and improve their efficiencies – and subsequently, their long-term contribution to sustainability.