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By Hernan Escalante, Jonathan Alvis, Paulo Alcazar

Constancia Mine, operated by Hudbay Perú and located in the district of Velille, Chumbivilcas province, Cusco, is an open-pit operation characterized by low-grade ore. In this context, operational efficiency and process optimization are essential to ensure long-term profitability. This paper presents an innovative strategy based on the processing of large volumes of data (Big Data), primarily from the drilling and blasting stages. By consolidating approximately 9 million records per month into a georeferenced block model, an analytical platform was developed to directly correlate material fragmentation quality with plant mill throughput. The implemented methodology integrates multiple operational and geometallurgical data sources, enabling dynamic visualization of blasting conditions and their impact on material behavior during crushing and grinding. Through this correlation, operational patterns that maximize plant throughput while minimizing energy consumption and processing costs were identified. Beyond the direct benefits in the plant, this approach significantly improved mine planning by enabling more informed decisions regarding drill pattern design, explosive loading, and blast sequencing. Improved coordination between mine and plant departments was also observed, contributing to better alignment of operational goals and an integrated business perspective. The application of Big Data in this context represents a step toward digital transformation in mining, demonstrating that advanced analytics can be effectively implemented in large-scale, complex operational environments. This solution was validated under real operating conditions and shows high scalability potential for other operations facing similar challenges. In conclusion, this study demonstrates that systematic analysis of drilling and blasting data, when integrated with geological and operational models, can lead to substantial improvements in plant performance. This contributes directly to the competitiveness and sustainability of low-grade mining operations.

Jan 26, 2026

By Jason Wilkinson

Drilling operations are a vital component of surface mining, directly influencing productivity, safety, and cost efficiency. This paper explores a multi-faceted approach to drill optimization, focusing on minimizing delays, and enhancing operational effectiveness. Key areas of inefficiency such as shift changes, fuel and water delays, and time lost between drilling holes are analyzed to identify actionable improvements. Equipment related factors, including the frequency of drill bit and drill steel changes, as well as the condition of deck bushings, are evaluated for their impact on downtime and performance consistency. Additionally, the integration of smooth drives and shock subs is examined for their role in reducing vibration related wear and improving drilling precision. Optimization of pattern approach strategies is highlighted as a means to reduce non-productive movement and align drilling with blast design more effectively. To support continuous improvement and accountability, the implementation of a driller scorecard is proposed. This tool enables the measurement of individual performance based on key operational metrics, fostering a culture of data driven management. Through a combination of field data analysis and best practice recommendations, this study provides a comprehensive framework for enhancing drilling productivity in mining operations. The findings aim to support mine operators in achieving higher efficiency, reducing operational costs, and extending equipment life through targeted optimization strategies.

Jan 26, 2026

By Italo Onederra, Miguel Araos

Most of the current explosives for mining blasting activities rely on voids to become sensitive to initiation, then detonating and finally, sustaining that detonation. The use of voids is known as hot spot sensitisation. Various forms of voids serve as hot spots – gas bubbles (predominantly in bulk explosives), glass (or plastic microballoons, for packaged products), or expanded polystyrene (bulk explosives). Gas bubble sensitisation uses the decomposition of sodium nitrite to produce nitrogen gas bubbles, which are dispersed throughout the bulk explosion. These gas bubbles, when hit by a shock wave (such as from a booster), compress and heat up, subsequently decomposing the explosive and releasing energy to sustain the detonation. It has been suggested that the use of different types of gases to create voids in non-ideal explosives could offer some alternatives to the sensitisation process, which could be reflected in the change of the detonation properties of the explosive. The reason would be that each gas has a different ratio of specific heats (=/), and when these gas bubbles are compressed, they will heat up to different temperature, affecting the decomposition of the explosive and thus, the VOD.

Jan 26, 2026

By Evan Smart, Andrew Palangio, David Klingspor, Blessing Taiwo

This study presents a DMAIC-based approach to optimize blasting performance and achieve crusher-compatible fragmentation at the Walker-Severn Quarry in Ontario, Canada. By applying the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) framework, the study aims to enhance the integration between blasting and primary crushing operations. Several representative blasts will be simulated and evaluated using both aerial and terrestrial image analysis technologies to assess fragmentation characteristics. The investigation was guided by quarry-specific Key Performance Indicators (KPIs), ensuring that blast design modifications were both practical and operationally relevant. Through structured analysis and data-driven refinement of blast parameters, the study reveals how this framework was used to address the quarry production demand for increased crusher throughput, and reduced processing costs. The existing quarry blast design was assessed as a baseline and compared against the crusher's inlet requirements and the acceptable fines level specified by the quarry. This evaluation aimed to identify and implement modifications to enhance blast performance. A drone (UAV) was employed to capture post-blast images and monitor blast pile displacement. These UAV images were used to generate an orthomosaic image, which was analyzed to assess fragmentation. The orthomosaic was overlaid onto a GIS platform using a 10m-by-10m grid to evaluate fragmentation distribution across the bench and identify areas requiring optimization. Additionally, drone imagery was utilized to monitor the impact of each blast on the subsequent blast's free face and to assess energy utilization for optimizing front-row holes to achieve improved fragmentation. The outcomes of this research offer a replicable methodology for continuous improvement in quarry blasting practices, with a focus on producing fragmentation that aligns with primary crusher requirements.

Jan 26, 2026

By Iván E, Alex Araya Jofre, Jean Guiroux Toro, Eduardo Valdés Guerra

Currently, it is important for companies to have controlled mining operations and adhere to production schedules. To achieve this, one of the key factors is maintaining high reliability in the P&T process, primarily the opening of ore stope, which could be delayed due to any unplanned or uncontrolled problem. These ore stope opening processes, whose main activity is generating free face, are a very important pillar for future mine planning. The possibility of ensuring their opening brings a series of downstream benefits: safety, economics, productivity, and compliance and adherence to plans. The process under discussion consists of developing free faces in a single blasting event. This will help us leverage greater reliability for overall production operation plans, reduce construction times, and open up opportunities for downstream improvements in the production process, considering technical factors in P&T designs. This study presents a developed methodology and shows the results of its implementation in ten (18) single-event free face blasts. The analysis includes cavity geometry, geology, rock qualities, drilling deviations, and the blasting strategy implemented for each event. The methodology used considered material fluffing processes, the actual drilling trajectory, the initiation sequence, QA/QC during explosive loading, monitoring instrumentation (vibrations), and VOD recording, among others. As a result, out of a total of 18 free-face events blasts in a single event, 16 were successful and two achieved 90% efficiency, reducing the stope's production start-up time by 50% compared to current operations. By implementing free face blasting in a single event, there are savings in operating costs, increased productivity of the mining equipment, and improved adherence to production plans. For applications with greater heights of free faces, where blasting cannot be carried out in a single event, we should consider performing them in two stages using wireless detonators already available on the market for mining operations.

Jan 26, 2026

By Hector O. Romero, Paulo C. Fernández A, Christian Rees Prado, Claudio C. Gajardo

In open-pit mining, estimating post blasting displacement and spillage accurately is essential to guarantee operational efficiency, ensure alignment with production plans and their associated key performance indicators. The absence of predictive modeling tools on blasting operations results in several critical challenges, including operational reworks due to deviations in material displacement, significant discrepancies between mine and plant (ore grade dilution included), misalignment with the reported production plan, and increased operational costs due to inefficient use of resources. This study, conducted at Los Bronces Mine operated by Angloamerican, Chile, addresses the application of a three-dimensional simulation tool that, through numerical modeling, is capable of predicting post blast rock displacement. The implementation was carried out in a pit phase characterized by blasts near the pit boundaries, with a high risk of material spillage and potential blockage of the only access ramp to the extraction levels. By the integration of key design parameters, such as blast pattern geometry, detonating time, explosive charge distribution and pre and post blast survey, an optimal calibration was achieved and validated in seven blasting events to date, reaching an accuracy greater than 80% in estimating post-blast rock displacement and spillage volumes. Furthermore, this study allowed the evaluation of different pattern alternatives with and without spillage mitigation measures (use of air decks near the free face), obtaining a high correlation and accuracy exceeding 95% in predicting the selected design outcome, supporting optimal design selections. The result highlights the usefulness of the model as a decision-support tool for blasting engineers and short-term planning, by reducing the need for unnecessary operational reworks, improving geological and operational reconciliation, and ensuring the alignment of the extracting plan with production targets. The current average deviation is 15%, with higher deviations observed in blasts with smaller volumes of spill or where the simulated sequence was changed before blasting. The use of this type of three-dimensional numerical modeling represents a significant advancement for blast engineering and the optimization of key performance indicators in open-pit mining operations.

Jan 26, 2026

By A. S. Romphf, C. K. McKenzie

Recent full-scale field studies involving single-hole charges fired to free faces under a wide range of operating conditions have delivered precious insights into airblast characteristics and propagation. The field tests involved production blasthole diameters in the range 89 to 406 mm (3 ½ to 16 in), bench heights in the range 9 to 24 metres (30 to 79 ft), burden ratios (burden/hole diameter) in the range 14 to 51, stemming ratios (stem height/hole diameter) in the range 11 to 36, explosive types of ANFO, heavy ANFO and pumped emulsion, and both solid-column and double-decked charge configurations. Around 700 measurements of peak amplitude and wave shape were made in all directions (0 to 360 deg) from the free face, from 38 single-hole tests in nine North American operating quarry/mine environments. The most striking observations were the strong dependence on directionality of the wave propagation parameters and wave frequency, the consistency of wave shape which resembled the modified Heelan wavelet, and the occasional appearance of distinct, multiple pulses from single events, shown to be echoes/reflections from quarry faces. In-hole deck charging failed in this study to achieve expected peak overpressure reductions, with the peak overpressure levels in Pascals/psi/millibars being approximately 40% higher than the as-charged weights. Inter-deck delay times in excess of around 25 ms are required for effective reduction of peak overpressure levels from front-row holes. Simple linear-superposition models based on synthetic wavelets applied to large production blasts produce composite waveforms which capture the important features of the actual pressure-time history, and correlate well with measured waveforms.

Jan 26, 2026

By Blenda Lopes, Rodolfo Matias, Vagner Paixão, Vinicius Leão VALE, Edivarde Sousa

Seismography is an extremely important subject in the context of rock blasting, especially in the current scenario, which involves the need for increased controls due to the growth of urban areas near open-pit mining operations. Worldwide, communities are becoming increasingly aware of the environmental and social impacts associated with mining activities. Therefore, maintaining good relationships with these stakeholders is essential to preserve the social license to operate and to comply with current legislation. This situation is exemplified in an open-pit iron mine near the capital of Minas Gerais, Brazil, where the community is located less than 40 meters from the pit boundaries. Blasting activities within the mining area occur at distances less than 500 meters from the nearest community, making continuous seismograph monitoring necessary to ensure that operational conditions are maintained without compromising exploitation efficiency. The threshold for peak particle velocity, according to Brazilian Standard 9653:2018 by ABNT, is 15 mm/s at frequencies around 4 Hz. However, even though the peak particle velocity commonly registered was inferior to 3 mm/s, there were still complaints from nearby residents regarding human discomfort. To further reduce vibration levels, a study was conducted to implement a new blast design, considering factors such as reducing bench height, altering the hole delays, maintaining the maximum charge per delay, and adjusting the drilling pattern without negatively affecting rock fragmentation quality. Following the implementation of the revised blasting parameters, seismographic measurements in the region decreased to below 0.6 mm/s. This significant reduction in ground vibrations contributed to minimizing community disturbances and fostering a more positive relationship between the company and its surrounding residents.

Jan 26, 2026

By Johan Hillman, D. Scott Scovira, Thomas Gustavsson, Alexander Bihlar

Hydrogen Peroxide Emulsion (HPE) explosives are an alternative to conventional commercial explosives. HPE does not contain nitrates or ammonia thus eliminating post-detonation NOx fumes and aqueous nitrate discharge. Production of HPE is less carbon intensive than industry standard ammonium nitrate-based emulsions (ANE) and employment aligns with end users seeking to meet Scope 3 ESG emission targets. Swedish tunneling contractor Implenia Sverige was awarded the Högdalen Depot Expansion Project by the City of Stockholm. Implenia Sverige partnered with Hypex Bio to be the first to pilot the application of a nitrate-free explosive system in a large-scale civil construction tunnel. The purpose of the joint project was to evaluate the operational suitability of replacing conventional nitrate-based bulk explosives with HPE in a large-scale tunnelling project. When the project commenced in September 2023 both standard nitrate-based emulsions and HPE emulsion were used in parallel (Tunnel Right and Tunnel Left) to enable operational, performance, and environmental comparison. Identical drill patterns and initiation techniques were applied to both tunnel headings. Performance data collected included round advance, usage, and perimeter quality. Implenia managed all drilling and charging operations and Hypex Bio provided technical support, including technicians and chemists. HPE is viscous and pumpable using conventional emulsion pumping delivery systems. Variable density functionality enabled loading different charge weights into cut, lifter, production, and perimeter holes. The primary rock type was hard sedimentary gneiss with approximately 150 MPa [21,755 psi] Uniaxial Compressive Strength (UCS). Fracture systems with infilling occurred in both tunnel directions. Rock quality factor was “Good to Very Good” on the RMRb (Rock Mass Rating) scale. Epiroc Boomer rigs were used to drill rounds averaging 4.9 m [16 ft] deep with high accuracy and precise reference positioning.

Jan 26, 2026

By Diogo Fonseca, José Manuel, Nuno Fernandes, Francisco Monteiro, Andrew Palangio, Blessing Taiwo

This study aims to enhance the integration between blasting and primary crushing operations in quarrying by optimizing the size of oversize and bypass fragments, ultimately reducing energy consumption. Using simulations of multiple blast rounds at the dstgroup aggregate quarry in Portugal, the research seeks to refine blasting practices and improve crushing efficiency. Part 1 of this study, presented at the International Society of Explosives Engineers' 51st Annual Conference, introduced a baseline framework for assessing the compatibility between blasting outcomes and crusher requirements. This methodology was applied to two blasting rounds, revealing discrepancies between expected and actual fragmentation results. The assessment raised key questions, including the root causes of fragmentation mismatches and the identification of controllable parameters that can be adjusted to align the particle size distribution (PSD) with the crusher’s optimal input range. Based on these findings, six key modifications were proposed to improve blast performance: (1) reducing the drill and blast pattern to limit boulder formation in the overlapping regions of hole influence, (2) increasing both the size and length of stemming material to enhance energy confinement, (3) decreasing subdrill depth to prevent toe burden issues from toe deviation, (4) modifying inter-hole timing to relieve back hole burden, and (5) improving drilling accuracy. Part 2, presented at Fragblast 14, explored advanced modifications to the initial blast design. The first adjustment was reducing subdrill and altering stemming material resulted in an 11% reduction in D80, a 19% decrease in maximum fragment size, and a 21% improvement in blast fragmentation efficiency. These changes shifted the PSD by 15% closer to the crusher compatibility envelope established in Part 1. Despite these improvements, boulder generation persisted in the front and back rows of the blast. This third part of the study focuses on implementing the remaining recommended modifications from Part 1 to further enhance blast efficiency and ensure crusher compatibility. The findings contribute valuable insights into the benefits of integrating blasting and crushing optimization strategies to achieve more consistent and efficient fragmentation outcomes.

Jan 26, 2026

By Jorge Cardenas, Diego Sanchez

Maximizing SAG mill throughput and metallurgical recovery in hard rock operations requires achieving target fragmentation, particularly a sufficient proportion of fines (<25.4 mm). These fines thresholds are strongly influenced by rock mass competency, commonly characterized using the Axb parameter (30–70) from the JK Drop Weight Test. In many operations, conventional blasting designs and standard emulsions fail to generate the fines content required for efficient downstream comminution. This study evaluates several advanced blasting strategies aimed at enhancing fines generation in very competent rock masses while maintaining cost-effective drill and blast performance. The first approach focuses on steadily increasing the powder factor (kg/t) as a core strategy, complemented by adjustments in blasthole diameter, reduced burden and spacing, the use of dual initiation points, short inter-hole delays (<25 ms), and optimized sequencing—all aimed at enhancing energy distribution and maximizing fines generation in highly competent rock masses. The second strategy consists of increasing the energy factor (kJ/t) by selecting explosives with higher energetic content and detonation performance. This includes the use of heavy ANFO blends and ultra high-energy emulsions with aluminum-based formulations, achieving Relative Bulk Strength (RBS) values between 180–190 and up to 210–230, respectively. These products offer higher detonation velocity (VOD) and peak pressure, enhancing shock energy transmission and breakage efficiency. Field results in granodioritic porphyries with high uniaxial compressive strength showed a 3–5% increase in fines generation compared to standard emulsions—contributing directly to meeting mill performance targets in high Axb conditions. Combined, these strategies provide a practical and technically validated pathway to achieving fines generation targets required for optimal mill performance. When matched to site-specific rock mass characteristics and integrated with blast monitoring tools, they enable improved fragmentation control, reduced P80, and enhanced plant throughput—without compromising operational efficiency or increasing costs disproportionately

Jan 26, 2026

By Brian Warner, Siavash Mahvelati, Douglas Rudenko, Mohamad Sharif

Predicting and optimizing production shot vibrations using time-shifting and superposition of signature hole waveforms (seed waves) has been widely used for many years. In this method, a single borehole is detonated and recorded with seismographs at the locations of concern. Since a single hole waveform is a reproducible event, it is reasonable that the seismic signature from a multi-hole production shot can be predicted by summing a series of single hole waveforms that have been time‐lagged at intervals corresponding to delay times from the production shot. However, there are instances where seed waveforms are collected at locations other than the exact location of concern, which raises questions regarding the applicability of such recordings. The present study adopts the well-known concept of dispersion of surface waves to predict seed waves at a location of interest based on seismograms recorded at a closer offset. Surface waves, as their name suggests, are seismic waves that propagate along the Earth's surface. They are the dominant wave type within one wavelength from the ground surface. Surface waves are dispersive in nature meaning that in a layered medium, wave components with different frequencies travel at different velocities causing an input signal to disperse as it propagates. The proposed technique takes seed waves recorded at one location as the input and passes it through a frequency-dependent function developed using site dispersion characteristics. The site’s dispersion characteristics are either measured directly with surface wave methods or retrieved using shear wave velocity information. The output of the function is the seed wave prediction at the farther location of concern. The theoretical background, including the underlying assumptions and limitations, is discussed in detail, and the application of the technique is illustrated through field data from two sites.

Jan 26, 2026

By Owen Collins

In surface mining, designing patterns to reduce the probability of flyrock and optimizing fragmentation through powder factor calculations are important for safe, efficient blasts. The designed powder factor is established for the blast once parameters such as burden, spacing, stemming, and powder column height are determined. In practice, these parameters are usually constant throughout a production blast with row-to-row burden and spacing. However, challenges can arise with the introduction of an open face. Many variables could necessitate the adjustment of the face row to optimize blast results. Variables include drill accessibility, challenges with toes, overhangs, and geology. The approach is often, but not exclusively, determining how to keep a consistent powder factor from the open face through the body of the blast. However, the solutions used vary case-by-case and rarely are two blasts the same. Technology has improved the ability to deal with challenging face conditions. 3D modeling with the aid of drones allows the application of angled holes to be more effective and simpler. This is just one instance where technology has improved blast results. This paper will present solutions to challenging face conditions. Thoroughly analyzing instances where challenging open-face variables were met with an effective blast solution could help provide insight as to what yields consistent blast results.

Jan 26, 2026

By Hector O. Romero, Paulo C. Fernández A, Christian Rees Prado, Claudio C. Gajardo

In open-pit mining operations, the presence of remnants from past underground labors represents a significant operational challenge, especially if they are in the surroundings of high-grade zones. The existence of uncrushable elements, such as metallic support fragments of abandoned equipment, can trigger critical operational issues if they reach conveyor belts systems or primary crushers, jeopardizing the mine to plant operational continuity. These kinds of incidents lead to expensive unplanned shutdowns, the increasing of corrective maintenance events costs, and risk to meeting expected production results. This work demonstrates the application of a three-dimensional numerical modeling tool for simulating rock displacement post-blasting (by integrating key design parameters, such as blast pattern design, detonating times, charge distribution and pre and post blast surveying). The study was conducted at Andina Mine, operated by Codelco, Chile, and enabled the identification and zoning of areas with potential presence of underground hazards in displaced rock mass, using historical data from previous workings and geotechnical mapping. The displacement results were compared to the actual post-blast surveying, ensuring an acceptability level above 80%, considering both fully confined (bank opening) and free-face blasts. Additionally, this approach allows the determination of an optimal safety offset, initially set at 10 meters and currently under validation for potential reduction. The results supported the determination of safe extraction zones and the design of excavation, loading, and haulage strategies from mine to plant or stockpile, ensuring 100% reliability in the segregation of high risk materials. Implementing displacement simulations underscores their relevance in operational risk prevention and mitigation, adding value to short-term mine planning and strengthening the safety, efficiency and profitability of the open-pit mining production process.

Jan 26, 2026

By Sebastián Seria, Jorge Álvarez, Diego Cáceres

The capacity to break the rock into adequate size fragments and in a cost-effective way is one of the main challenges in large open pit copper mines in Chile. That capacity is often compromised by the accuracy of geological estimations and the resources allocated by the mine site to update those models, making the blasting design highly dependent on that input and in consequence, blasting results. Given these opportunities, having an alternative method to input estimated key geological parameters allows blast designers to modify their designs and apply the appropriate energy to achieve the desired results. By using measurement-while-drilling data from boreholes and a few samples of actual, widespread, hardness measurements on site, we can deliver an updated cost-effective hardness estimation that is used as an input to improve the blasting design and its results on fragmentation. This estimation is delivered as a hardness interval – often in MPa units- related to the position of actual drilling measurements. In addition, having a sufficiently large drilling dataset allows us to predict hardness in new, undrilled areas near already measured boreholes, serving as a prior estimation available before pattern design. The use of these estimations, applied to several copper mines in Chile, allow us to more accurately determine explosive amounts and borehole drilling, which directly contributes to more productivity and efficiency in mine site operations. The results are often related to narrowing the gap for fragmentation results, even so, in some cases that will be related to direct savings in Drilling & Blasting process in a range 5-10% of the budget, due to powder factor changes.

Jan 26, 2026

By Alastair Torrance, Gary Cavanough

Approximately 1.5 million tonnes of ammonium nitrate are transported annually across Queensland, Australia—equivalent to nearly 100 truckloads per day. This is in the form of both AN prill and ammonium nitrate based emulsions (ANE). In a recent incident, a collision involving an ANE tanker resulted in a detonation that caused extensive blast-related damage and led to the closure of a major highway. Had this event occurred within a populated area, the consequences would have been catastrophic. For over a century, investigations into the causes of such spontaneous detonations have been inconclusive. A recently completed industry supported research project has made a pivotal discovery: a surface reaction mechanism leading to hydrogen generation has been identified as a precursor to detonation. If sufficient hydrogen accumulates and subsequently ignites, it can release enough energy to initiate the detonation of bulk ammonium nitrate and ANE. Controlled experiments conducted during the project successfully demonstrated hydrogen-driven detonation events. Previous work by Proulx and Scovira, presented at the 2000 ISEE Conference, described spontaneous detonations in hot, reactive ground and the mitigating effects of buffered emulsions and ANFO. Building upon their observations, this study reproduces similar incidents under laboratory conditions, confirming that hydrogen generation also results from reactive ground interactions. Importantly, the findings challenge traditional assumptions, demonstrating that ammonium nitrate and ANE detonation in reactive environments does not require an ignition temperature threshold, confinement, or a classical chemical decomposition pathway.

Jan 26, 2026

By Thomas Palangio, Blessing Taiwo

Image-based fragmentation analysis is increasingly utilized in blasting operations to evaluate particle size distribution in a non-intrusive and efficient manner. However, the accuracy of optical granulometry systems can vary significantly with particle size. Higher precision is typically achieved for larger fragments, generally those greater than golf ball size when using drone-based orthomosaic analysis. In contrast, the detection and delineation of fine particles become less reliable due to constraints such as pixel resolution, particle overlap, and partial burial within the muck pile. This variability does not undermine the value of image analysis but rather highlights the need for a deeper understanding of its operational thresholds and the integration of complementary methods or calibration approaches to improve its reliability across the entire particle size distribution. Technologies such as WipFrag, originally developed in the 1980s, are designed to conduct in-situ fragmentation analysis within complex blast environments, where fines are often obscured by larger fragments. The challenge becomes more significant in blast rounds exhibiting wide gradation ranges and increased fines, particularly resulting from excessive energy concentration in high-pressure zones near the borehole. Previously, this issue was addressed through methods such as analytical correction, zoom-merge correction, and empirical calibration using Rosin-Rammler and Swebrec distribution models. However, these traditional empirical calibration approaches, particularly those tied to distribution functions like Rosin-Rammler have shown limitations, especially in accurately representing the fine region of the fragmentation curve. In contrast, the recently developed xP-fan model, which incorporates the relationship between powder factor and fragment size, introduces the fragmentation energy fan principle which Kuz-Ram model does not entail. This paper presents a study on the application of the novel xP-fan calibration to enhance the accuracy of optical granulometry systems. The findings demonstrate how xP-fan help calibrate the fine region of the PSD without deflecting the maximum size.

Jan 26, 2026

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By Jeremiah Cohn, Rachel L. Bauer, Catherine E. Johnson

Water is frequently used in explosive applications to increase explosive performance and reduce air overpressure. Water tamping can enhance cutting abilities of shaped charges in demolition and increase impulse of kicking or breaching charges. In explosive disposal, water is used to suppress air overpressure and reduce noise. Despite its widespread use, the specific effect of water placement, whether in front of or behind the explosive, has not been studied. This work evaluates the directional effects of water placement on blast performance using 400-gram sheet explosive charges in five configurations: no water (control), rear-only water (tamped), front-only water (pushed), water on both sides (confined), and a thin front-and-rear water layer (low mass confined) to assess reduced mass effects. Water was sealed in plastic bags and held in position with custom 3D-printed cages to ensure consistent geometry and contact. A modified ballistic pendulum consisting of a hanging steel W-beam was used to evaluate impulse transfer, with high-speed video capturing swing velocity. Air overpressure was recorded using a seismograph microphone. Rear-only water (tamping) increased beam swing velocity by 69% over the control while confinement with water on both sides increased performance by 12% at a 2:1 water-to-explosive ratio and by 50% at 4:1, though it still underperformed the tamped-only configuration. Pushed water alone did not increase beam momentum and reduced tamping effectiveness by 19% when combined. Seismograph microphone data showed that pushed and low mass confined water configurations produced some of the highest air overpressure levels (up to 139.2 dB), while tamped and control charges produced lower levels (~134–136 dB), suggesting that pushed water may amplify, rather than mitigate, air shock transmission. These findings show that water placement has a strong directional influence on blast dynamics: water behind a charge enhances energy transfer to the target, while water in front provides limited or potentially counterproductive mitigation. This study advances understanding of water–explosive interactions and will lead to more effective charge designs for breaching, disposal, and demolition.

Jan 26, 2026

By Carrie Smith

In 1972, in Denver, CO, five women with a shared goal joined forces to create the first formal space for women in the mining industry: Women in Mining USA (WIM USA). When the organization first took shape, few could have predicted that a small gathering of women would grow into one of the most influential organizations that would advocate for inclusion in the industry. Now, more than 50 years later, the group remains a vital network for professionals across the United States with a diverse array of membership and chapters.

Jan 1, 2026