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By A. Ribeiro

The effective utilization of resources and process optimization play a crucial role in the sustaining and growth of overall businesses. This principle holds true in the mining sector, where particular attention is required during the comminution steps. This necessity arises from the fact that mining operations often consume substantial amounts of energy in mineral processing. Therefore, it becomes imperative to thoroughly study the integration of comminution steps. In many instances, an approach to be studied is the operation commencing with the drill and blast phase and culminating in the grinding product process. Nevertheless, establishing an optimal integration between drill and blast operations and the grinding phase is a complex undertaking due to the direct influence of rock characteristics on this process. And in many cases, the complexity and variability of such physical characteristics makes mining operations to ignore such influence. Consequently, Enaex Mining Technical Solutions (EMTS), in collaboration with Lundin Mining's Chapada Mine engineering team, and with the assistance of Hatch Consulting and Technology, has undertaken a comprehensive study aimed at enhancing mill throughput at the Chapada operation. The basis of this study lies in characterizing the rock masses present in the Chapada Mine to gain a deep understanding of the material that needs to be comminuted. Subsequently, the mineral processing team determined the most suitable size distribution for the Run-of-Mine (ROM) material. With this information, the drilling and blasting team built a site-specific blast fragmentation model, able to simulate various blast design scenarios. This approach enabled to optimize the utilization of available drilling and blasting resources while striving to achieve the optimum ROM characteristics. Since 2021, the Mine to Mill methodology has been progressively implemented at the Chapada Mine. As a result, the blasting engineering team now utilizes the blast plans generated by the fragmentation model simulations as a foundation for designing blast plans that align with the operational and financial capacities of the mine. Overall, it was predicted that this implementation could lead to an average increase in mill throughput of 13-22 % depending on blend feed, once all recommendations are implemented. Even with partial implementation, plant results demonstrate a 5 % increase compared to the period before the Mineto-Mill project, without any coarsening of the associated grinding product size.

Jan 1, 2024

By Anderson da Cunha Meireles, Pedro Garcia, Ernst Young, Leandro Coelho, Carlos Eduardo Soares Feliciano, Key Fonseca de Lima

Rock blasting is a crucial technique employed in mining construction and quarrying industries to fragment large rocks into smaller, more manageable pieces. However, it often generates ground vibrations that can pose significant challenges. This study explores the application of Conformal Prediction (CP) in the context of rock blasting to develop predictive models that estimate blasting-induced vibrations and quantify the associated uncertainties. Various machine learning models were integrated within the CP framework using MAPIE and CREPES libraries. The results demonstrated the effectiveness of CP in providing statistically reliable prediction intervals, making it particularly useful for applications where the stakes of underestimating uncertainty can be high.

Jan 21, 2025

By John C. Didlinger

How do you measure the highwall? Why do you even need to know the highwall measurement? Why is it important? The importance of this measurement is to help keep a level floor and to help control vibration. Nevertheless, since most of us are not mountain climbers, there must be a safe and easy way to make an accurate highwall measurement. So with these factors in mind, how do you make your measurement?

Jan 1, 1997

By Jim Petrunyak, Conny Postpack

The authors describe in this paper a systematic approach toward reducing coal production costs up to 35% through the use of explosives energy for overburden removal. In this system, explosives are employed to blast as much as 65% of the overburden instantly from highwall to spoil pile, with only the lesser portion requiring removal by dragline, shovel, or loader.

Jan 1, 1983

By Thomas H. Kleine, Alan R. Cameron, William W. Forsyth

In general the software required by a blast designer includes tools that graphically present blast designs (surface & underground), can analyze a design or predict its result, and can assess blasting results. As computers develop and computer literacy continues to rise the development of and use of such tools will spread.

Jan 1, 1995

By Alan Bauer

During the past several years, the trend to large-diameter blastholes in both open pits and underground mines along with the continuing developments in slurried explosives and delay systems has kept things exciting for the drilling and blasting engineer. This has been particularly so in underground mining, where new mining systems having lower cost and higher productivity have emerged. Crater technology has produced new large-scale methods for resisting front penetration in tar sand mining and also new underground retreat mining methods and methods of raising.

Jan 1, 1978

By Piyush Rai

Proper use of fi ring pattern vis-à-vis the blast requirements can provide optimal blast performance in terms of fragmentation. Further to this, each fi ring pattern has its own characteristic, for instance, although V-type and diagonal fi ring pattern provide same Se/Be ratio, the V-type fi ring pattern increases the opportunity for in-fl ight collision amongst broken rock fragments during their movement. Similarly straight V-type and skewed V type fi ring patterns (V1,V2 etc.) have their own characteristic strengths and weaknesses. In this light the present paper highlights the application of three different types of fi ring pattern on two different type of sandstone overburden benches of a large coalmine in India. The study reveals that Firing pattern infl uences the effective spacing to burden ratio at the time of detonation. By changing the fi ring pattern, effective burden (Be) changes and the ratio of effective spacing (Se) to effective burden (Be) during the fi ring is also subject to change in comparison to drilled spacing to burden ratio (S/B) Hence, the Se/Be ratio vis-à-vis fi ring pattern must be used to design the blast rounds. The results have been derived on the digital image analysis based fragment size characterization, excavator performance and evaluation of powder factor values on blasted muck piles. Skewed V- type fi ring yielded the best results in comparison to straight v-type and normally practiced diagonal fi ring pattern on the moderately strong sandstone benches, whereas, the existing diagonal fi ring pattern appears to be satisfactory on weak (weathered and gritty) sandstone benches. The presence of geological anomalies has also been investigated.

Jan 1, 2008

By Mark A. Rugen

It may be difficult to imagine but small engineering companies do exist, even in relatively large cities like San Antonio. Due to the limited capital available for the purchase or use of equipment such as computers, many times the small company must evaluate a blast damage claim by limited means. This paper will discuss how a relatively small company has managed to become the leading blast damage experts in an area without the use of computers or sophisticated equipment. It will be shown that a single individual in a company who is familiar with vibration theory, local soil conditions and who does not mind spending long hours with a calculator and reference books can satisfy both the insuranc e adjuster or attorney, and the homeowner concerning the claim. Several examples will be given which show the typical flow of work and the ultimate outcome. This paper will focus on the special problems encountered by a small firm and how these can be overcome, and the unique interaction of a small engineering firm with both the insurance adjuster/attorney and the homowner that can lead to an equitable settlement of the claim.

Jan 1, 1983

By P D. Katsabanis, S Kim

A number of small scale fragmentation tests have been conducted to analyze the effects of blasting effort on the grindability of granite, granodiorite, limestone and iron ore. Powder factors were modified, post-blast fragments were screened and drop weight tests were conducted on fragments of different sizes to deliver a variety of specific impact energies. The fragmentation from the drop weight tests has been analyzed to examine the effect of impact energy and powder factor on size reduction. A consistent effect of blasting on the various fractions of the fragmentation distribution has been obtained for all rocks used. The effect of powder factor on the impact fracturing of the rocks has been expressed in a convenient relationship between progeny size, impact energy and powder factor used in obtaining the primary fragmentation. It is clear that explosives consumption affects downstream size reduction; depending on the rock, the effect can be substantial at coarser final sizes but very small in the case of grinding to small final sizes. Differences from the expected trend can be attributed to changes in blast design. As an example, the effect of in-hole collision of detonation waves is analyzed.

Jan 1, 2011

By Ian Tolliday

Emulsion Explosives manufacturers are aware of the destabilizing effect that the presence of inorganic impurities such as magnesium and iron and organic impurities such as naphthalene sulfonates and alkyl amines can have on their emulsions. This destabilization often manifests itself as severe crystallization and subsequent product loss. This paper describes the performance testing of specifically developed emulsifiers which give greatly improved emulsion stability in the presence of high levels of impurities. The test work involved a series of stability tests using ammonium nitrate doped with various levels of crystal modifier and anti-caking agent. A further series of tests were done to evaluate the stability using ammonium nitrate doped with various levels of iron and magnesium ions.

Jan 1, 2018

By Carl E. Jones

This presentation discusses the properties of the two-component explosive, KinePak, and how it is used by the utility industry.

Jan 1, 1978

By M. Syafiq Isnaya, Rahma Norfaeda, Slamet Rachman Jaka

This paper is about project improvement to maximize energy distribution while ensuring beneficial blast results (reduce boulder condition). The main problem is how to manage complex lithology conditions related to detonation propagation in energy distribution control.

Feb 1, 2020

By Alain Blanchier, Pascal Bernasconi

Blasting operations took place on Channel coast NW of France to extend Flamanville Nuclear Power Plant (EPR new generation). The closest operating reactor building was monitored by a 24 remote vibrations transducers network to fulfil, on one hand, the severe environment constraints and satisfy high degree of productivity required by the project, on the other hand. Although these requirements usually are incompatible, this challenge compelled to introduce a seismic modelling technique to optimize blast designs using electronic initiating system. The “Hybrid Seismic Modelling” (MSH) uses blastholes signatures (seismic vibrations records) which are greatly dependent on geology and alteration of rock mass, explosives, charge geometry, blast configuration, and the final excavation shape. In order to respect severe vibrations limits, excavation layout was divided into areas with specific blasting modules - type and number of charges, single charge, initiating sequence. Thanks to this technique, it has been possible to reach lowest blasts vibrations levels and a better productivity compared to classical blasting operation at the same location in the past. After the modelling method presentation - principle and use precautions, technical improvements are reported.

Jan 1, 2008

By Radhe Krishna, Mutale William Chanda, Timothy Mwale

Blasting as a process is the emplacement of industrial explosives into blast holes suitably located to a free surface and detonated. Every blast hole containing a certain amount of explosive charge undergoes impulsive loading when detonated and results in the dynamic transfer of a powerful shock wave to the surrounding rock. It is the shock wave that brings about rock breakage when the tensile stress produced upon reflecting from the change in material density or free face overcomes that of rock material tensile strength. However, this shock wave comes along with unwanted destructive consequences such as damage to remaining rock, ground vibration, noise and fly rock. The above mentioned consequences pose a great threat to the Community of Wusakile, Kitwe as Mopani Copper Mines Plc wishes to increase its production by expanding the pit towards the community that lies within 150 m (164 yd) from the pit rim. As a requirement from the Zambia Environmental Management Agency (ZEMA), all blasting operations close to the community must maintain at least below the maximum vibration threshold of 10 mm/s (0.3937 in/s) PPV-Peak Particle Velocity or else risk closure of the mine (AMC,2009). In order to satisfy the above statement, a good understanding of explosives is required. This paper therefore presents the phenomenology of rock breakage by explosives with much emphasis on electronic blasting and how best this process can be controlled in densely populated communities. Factors affecting maximum projection distance such as, size of the fragment, shape of the fragment, angle of projection, the state of confinement of an explosive charge, were also studied. In addition, design faults, deviation in implementation and unforeseen geological conditions were also considered. The paper discusses the above facts based on research.

Jan 1, 2015

By J Silva Castro, Braden Lusk

Information management is important in all disciplines. In mining; collection and analysis of information before, during and even after mining is a keystone to performance. During mining, information is useful to optimize the resources and make appropriate decisions. Current technologies allow for collecting information in real time. Records of blasting activity at the mine are common practice in surface coal mining operations. The most common blast information recorded contains the location of the blast, scaled distance, geometry of the blast, weight of explosive used and quantity of blasted rock. Sometimes due to the proximity of protected structures, seismograph evidence of the particle velocity and airblast levels is required. However, in the majority of cases, the seismograph information is not linked to the blast information. Blast related information is recorded separately from the seismograph information and seismograms are little more than an attachment to the blast record. This fact makes simultaneous visualization and analysis of the technical details of the blast with the vibration and airblast information difficult.

Jan 1, 2012

By Dale Preece, Mike Stern, Steve Piercey, Ayman Tawadrous, GC Zhao

The McArthur River uranium mine in Saskatchewan, Canada is the world’s largest high-grade uranium mine. It has employed a freeze-wall system consisting of multiple freeze pipes to control the large quantities of water encountered during mining.

Jan 1, 2011

By Jair Alarcón, Lucas Steffen, Leopoldo Muñoz

Flyrock is one of the most significant hazards associated with blasting in open pit mining, especially for blasting operations near communities. Flyrock can lead to severe injuries, fatalities, and property damage, compromising the license to operate. For this reason, defining exclusion zones is critical to ensure the safety of people and equipment. A very large radius will reduce the risk of flyrock; however, excessive exclusion zones can significantly impact the productivity of the operation and, in some cases, compromise the extraction of ore in critical sectors. Many mine sites use distances derived from pre-established standards, experiences from other mines, or still use simple methods for analysis, like recording blasts with a terrestrial camera and performing deterministic calculations to determine exclusion areas, applying an arbitrarily safety factor for people and equipment. In this paper we present a new approach that allows the calculation of the exclusion zone by measuring critical flyrock parameters with a high degree of accuracy through a new video analytics technology, this data then is used as input to calibrate probabilistic flyrock models to have more robust calculations, allowing optimized and safe exclusion zones. The proposed methodology leverages high-accuracy data and continuous monitoring to dynamically adjust D&B designs and exclusion zones, ensuring maximum safety without unnecessarily restricting operational efficiency. A case study is presented where the application of these new digital technologies allows precise prediction and control of flyrock trajectories, enhancing the accuracy of exclusion zone boundaries. In this case we successfully reduced the exclusion zone radius to 100m, allowing the ore extraction in a critical region close to the community safely. The study shows notable improvements in safety and productivity, including zero flyrock incidents and enhanced protection for nearby communities. The adaptive nature of these digital tools offers scalable solutions for various blasting environments. The paper concludes by recommending the integration of these tools into standard blasting protocols, highlighting the potential for widespread adoption in the industry to mitigate flyrock risks effectively.

Jan 21, 2025

By Jim Peterson, Ricardo Freire, Mason Biernat

Variable nature of rock and face conditions, varying execution and changing nature of blasting are making ongoing optimization challenging. Intelligent planning and on-going analytics are required to mitigate variability and convert blasting into a predictable outcome by use of technology. Blasting operations generate a huge amount of data which can be used intelligently for optimization. In this paper, details are provided of a system which is used for blasting data collection in the field – Key details around blast parameters, explosives, initiating system details, video, photographs, vibration and fragmentation are collected in a cloud-based platform. Data can also be collected through a mobility device in the field (even without internet connectivity) and synchronized with cloud-based system. Also, data from various sources can be imported in excel formats in the software including from upstream and downstream processes from blasting. App also gives indication about exceeding of vibration, air blast overpressure, fragment size etc. Thus, making it possible to perform QA-QC before charging and deciding initiation timing and sequence at the blasting site. The data can be processed and analyzed to spot trends, help predict events, and formulate strategies at the design and execution stage. Data gathering of blast parameters, explosive used processing and analysis can be used to optimize operational efficiency, improve safety and environmental controls.

Jan 1, 2019

By Riaan Van Wyk, Gys Landman

In today’s mining environment the use of radio communications in the form of two-way radios, cellular phones and even automated mining, form a vital part of the daily operations of a mining site. The radio transmissions that are used are a form of energy and as with all other types of energy it can have an influence on blasting equipment.

Jan 1, 2011

By Roger Favreau, Patrice Favreau

Without blasting there can be no roads, no hospitals, no factories, not even foundations for homes. Yet in 1960 the only way to design a blast was by trial/error. By comparison, bridges were already designed by calculations before being actually built. This was possible because equations based on the fundamental principles of science existed with which all the stresses in the bridge could be calculated. In 1960 no equations based on the fundamental principles of science existed with which the mechanisms that take place inside the rock mass during a blast could be calculated. Since then the main author made it the objective of his research to seek such equations, and to validate that they gave accurate answers by means of experiments in the field, experiments made in co-operation with mines, quarries and the explosives industry; results have been reported in some 90 publications.These equations now deal with essentially all aspects of a bench blast: the intensity of the shock wave and the fragmentation size distribution throughout the rock mass; the movement of all the fragments into the muck pile; the fly rock and vibrations from the blast; etc.; are presented examples of such equations. They are now assembled into a computer simulator called Blaspa accessible on the Web, with which one can design a blast just as a bridge is designed. An example is presented. The reason to design a blast by simulations rather than solely by trial/error is that if it leads to damage, it is only after the actual blast that the blast design is realized to cause damage. If however the blast design had been simulated before the blast, then the risk of damage is identified before the blast and is prevented by redesigning the blast. Examples of such situations are presented. The need to a void damage is very necessary because the public is becoming opposed to blasting. When a blast does cause damage, and people learn that the blast was designed solely by trial/error even though simulation was available and would have prevented damage, they become even more strongly against blasting; they may succeed in getting a quarry closed. Their objections to unchecked blasting are not unreasonable, especially as simulating a blast with Blaspa on the Web is a very simple procedure.

Jan 1, 2013