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By Markus Pötsch, Andreas Gaich

Optimization of surface blasting based on 3D models from drone imagery and a closed loop that starts with an automatic analysis of the geometry and the geological conditions and ends with an objective assessment of the blast result.

Feb 1, 2020

By Wayne Rogers, Kell Monro, Arthur Pacunana

The Phu Kham Copper-Gold Operation (PKM) is a large-scale open pit mine located in northern Laos. It was developed and is operated by Phu Bia Mining Limited (PBM) a Lao-registered subsidiary company of Australian incorporated, PanAust Limited. Production commenced at Phu Kham in 2008. Since the second half of 2016, there has been a significant increase in ore hardness and this has negatively impacted the PKM concentrator and resulted in lower SAG mill throughput rates. Over the remaining life of mine, the changing ore body and increase in ore hardness is forecast to continue as the pit deepens and the availability of softer blending ores reduce. To manage this risk, PKM initiated a Hard Ores Management Program to determine the most effective way to improve the mill throughput of harder ores. This involved conducting a number of innovative and process control driven blasting trials to optimize run-of-mine (ROM) fragmentation and other blasting outcomes. From 2016 to 2017, the performance of high powder factor blasting, electronic detonators and fast timing, high velocity of detonation (VOD) explosives, double-priming, and deck blasting, were individually and systematically assessed. The success of each blasting trial was then based on a ‘value for money’ criteria. This criteria is a cost / benefit analysis that weighed-up the additional cost to implement the trial against the measured improvement in mill throughput. Electronic and high VOD 90:10 emulsion:ANFO blasts were determined to have the best value for money, achieving an increase in mill throughput of 54% compared to baseline. This paper discusses how the implementation of an innovative and process control driven blasting trial methodology was able to successfully manage the hard ore challenges at PKM. In addition, this success was achieved without any major cost implications, safety incidents or process plant set-backs.

Jan 1, 2018

By Claudio Lechuga, Carlos Scherpenisse, Juan Rafael Otaiza

From the analysis of drilling process, Block Model information, drilling pattern data and expected fragmentation targets; GBlast® software optimizes the explosive charge design in order to standardize the particle size of each blast.

Feb 1, 2020

By Angelina Anani, Seffit Aderuyi, Sylvester Avane, Joseph Wilson-Sey, Amatus Niminye

The Edikan mine in Ayamfuri, Ghana, faces economic challenges and community resistance due to its proximity to residential areas, particularly concerning blasting operations. Controlled blasting trials using air deck applications were conducted to address community concerns by minimizing environmental impacts and explosive costs. This method involves utilizing an air gap within blast holes to prolong the action of shock waves on the rock mass, enhancing crack formation and reducing rock movement. The trial project at the Edikan open pit gold mine aimed to evaluate the effectiveness of air deck blasting in reducing ground vibrations and overpressures, and to assess its impact on blast performance and economics in the prevailing geological conditions of meta-sediment and hard granite rocks. Results indicated lower Peak Particle Velocity (PPV) and Peak Sound Pressure Levels (PSPL) values in the air-decked blasts. Additionally, more uniform rock fragmentation and enhanced blast economics were achieved. Explosive costs were reduced by 20–24%, saving $0.97 to $2.24 per hole depending on the rock type. Overall blasting costs per volume decreased to $0.54 in granite and $0.48 in meta-sediment compared to conventional methods.

Jan 21, 2025

By J. P. Proulx, Richard O’Meara, Ruilin Yang

A blast optimization project was carried out at an Open Pit Metal Mine using the Multiple Blasthole Fragmentation (MBF) Model and the Multiple Seed Waveform (MSW) blast vibration model. The aim of the project was to optimize rock fragmentation of the ore blasts to significantly increase metal recoveries while keeping the blast vibration levels at the highwall under control. The project also examined the blasts in the waste rock using the Fragmentation model to expand the blast pattern and select economical explosives for drill and blast cost savings while minimizing any adverse effect on the dig rates. Two sets of near field signature blasthole tests were conducted in both hard ore and relatively soft waste rock. The information from the near-field signature blasthole vibration was used as input to both the MBF and MSW models, as site specific geological information interacting with blasting. The implementation of the full blast design is also input to the MBF and MSW models. A production blast for each rock type was monitored for blast vibration and rock fragmentation. The full blast information and the blast results are used to calibrate and validate the models. The Fragmentation and Vibration model were established for the two rock types at the mine. At each site the Fragmentation modeling was conducted in parallel to the Vibration modeling to ensure blast vibrations were under control while the rock fragmentation was improved. The Fragmentation MBF and MSW are each an integral part of the blast optimization tool. Various scenarios using different explosives, hole delays and blast patterns were modeled for rock fragmentation and blast vibration. The recommendations from the modeling project were to be field trialed at the mine. The implementation of the recommendations was expected to help the mine significantly in terms of the mining economics, and high wall stability and safety.

By Francisco Sena Leite, Vincius Miranda, PhD Machado Leite, PhD Pinto, Raquel Carvalhinha, Alexandre Julio, Dorival de Carvalho

Rock blasting, in particularly the drilling process, is one of the first processes in the stage of rock fragmentation and plays a fundamental role by influencing all the following stages. Given its importance, some proposals to optimize this process have been presented over the last few years. These proposals, while having different approaches, aim (in a large part) to minimize the costs of drilling and blasting respecting the limits of fragmentation required by primary crushing. Reviewing some recent articles leads us to an enriching experience, since the authors of these articles clearly model the problem, but do not address the mathematical solution of these models, which in turn, given their non-linear nature, have no directly and easy solution. Simple and even robust optimizers present in the market show different results and often do not converge to a single solution. To address this problem, an adapted gradient heuristicbased model was developed to try to find optimum values. Heuristics search for values of stemming, subdrilling, burden and spacing that minimize the costs of blasting and drilling. This search, which by the nature of the heuristic moves the solution in the direction of the gradient with maximum decrease to find optimal solution, found values that in turn, when compared with values presented by market solutions not only equaled them as, in some situations, even improved the proposed solution. The algorithm was tested and validated on the field, and although the results have already been presented in papers published in the last year by the authors of this paper, it is now presented with its mathematical formulation and comparison with the other solutions. This approach is expected to be able to improve (and even demystify) the process of pattern expansion and be the basis for future work in the continuation of the optimization process.

Jan 1, 2019

By Doug Anderson

Blast vibration seismograms are generally collected strictly for compliance with regulations. The peak levels (including dominant frequency) are typically all that are looked at. However, these records contain a lot more information about how a blast has performed. The seismogram is actually a record of explosive energy that was not used in fragmenting rock. The trick is to determine how to extract information that would be useful in analyzing blast performance.

Jan 1, 2013

By J A. Hacked

This paper explores the potential to exploit controls over the outputs of the primary blasting operation, arising from the performance consistency benefits gained in using modern bulk emulsion explosives technology. The former, allied with the latest powerful blast predictive software and measuring tools, offers the user the opportunity to apply control over both cost and performance, which has not been possible in the past.

Jan 12, 1997

By Glenn Keep

THIS paper is not an announcement of the successful conclusion of the Cerro de Pasco Copper Corporation's pacos-pyrite problems, but merely a description of the commercial-scale, intermittent-roasting operations conducted by the writer, J. H. Lucas and others of the staff. It was prepared by request, for presentation at the February meeting of the Institute. The results obtained in Peru confirm the 1-ton-a-day experiments completed about three years ago at Kearny, N. J. by C. C. Gordon and Mr. Lucas, where it was first demonstrated that a mixture of about 80 per cent. pacos ore with 10 per cent. pyrite ore and 10 per cent. salt could be roasted intermittently in a small 1-ton-a-day Holt-Dern furnace without extraneous fuel, producing porous calcine that could be leached rapidly. Mr. Keep and his staff, by successfully introducing improvements in the construction of the commercial furnace and in their handling of material, have established beyond doubt a low cost for roasting. The other steps in the process of treating pacos and pyrite ores have not as yet been demonstrated as sufficiently conclusive to warrant their acceptance for a permanent plant.

Jan 1, 1929

By Stephen H. Chung, Kevin Atherton

The main purpose behind this preliminary study was the reduction of costs while maintaining productivity. Finding a way to achieve this balance without compromising controls on safety and quality of blasting results is of continual interest to the mining industry and of particular interest when ore of lower grade is being mined.

Jan 1, 1998

By G. K. Jorgenson, S. H. Chung

"IntroductionThe SABREX Blast Modelling Program was developed jointly by the companies of the ICI Explosives Group, of which C-I-L Inc. is a member. SABREX (Scientific Approach to Breaking Rock with Explosives) is a modular computer program which incorporates new technology with a number of tested programs that have been in use world wide.SABREX predicts the performance of blasts in terms of (I) fragment size and distribution; (2) muckpile profile and face velocity; (3) grade fracture; (4) collar breakage; (5) a rupture envelope which depicts crack penetration behind and beneath blastholes; and (6) a complete cost analysis including explosives, drilling and accessory costs. The predicted blast results are displayed as dynamic colour graphics and in tabular form.SABREX uses data on the detailed geometry of the drilled and loaded pattern, detonation characteristics of the explosives and the dynamic properties of the rock to generate blast predictions. SABREX blasting calculations take into account the effects that shock and quasi-static pressures exert on the rock around the blastholes. While physical effects occur very rapidly in rock blasting, it is possible to view and model the sequence of events as discrete sections.The program can be run on a microcomputer and is currently operated by C-I-L technical service staff in Canada for the use of drilling and blasting operators.Figure I is a diagram representing the modules of the program and associated technology that is used to complement the program.Any, or all, of the modules may be used in a particular study or blast optimization. Because the BOBCAT module of the SABREX program has been described in previous papers(7.8.9), this discussion will concentrate on the newer modules: CRACK, HEAVE, RUPTURE ENVELOPE and to a limited extent, KUZ-RAM, which present a more detailed picture of the blasting process.Each of these modules is discussed in terms of the information they offer the operator in analyzing the blast. Specific examples of recent usage in Canadian mining situations are included to illustrate the ability of the model to produce practical results that can assist in optimizing actual blasting operations or solving problems that do exist."

Jan 1, 1987

By G K. Jorkenson

The SABREX Blast Modelling Program was developed joinlly by the companies of the ICI Explosives Group. of which C-I-L Inc. is a member. SABREX (Scientific Approach to Breaking Rock with Explosives) is a modular computer program which incorporates new technology with a number of tested programs that have been in use world wide.

Jan 1, 1989

By Unknown

Blast Site Security Involves: * Clearing the area * Controlling Access * Warning Signals

Jan 1, 2003

By Jonathan Heiner

Rio Tinto Bingham Canyon Mine started its South Wall Push Back (SPB) in 2011. This push back will mine through the only road to the pit bottom (the 10%). The pit bottom is the main ore sector for the mine and supplies about 80 to 90% of the ore. In late 2017 the mine set off a blast in SPB that created a small wedge failure on the high wall between SPB and the 10%. This wedge failure released a rock approximately 20 minutes after that blast that rolled down the wall landing on the 10% near and then contacting a light vehicle

Jan 1, 2019

By Nikolaos Petropoulos, Ulf Nyberg, Daniel Johansson

A series of signature boreholes were blasted to observe any difference between confined and free face blasts. Four geophones were used to capture the compressive wave. The conventional approach, i.e. the calculation of vectorized peak particle velocity (vPPV) did not show any difference. Also a wavelet transform was tested.

Feb 1, 2020

By Randall M. Wheeler

"Fourier analysis is a very powerful frequency analysis tool. However, it is frequently misunderstood and sometimes used inappropriately. Part of this workshop will involve the basics of Fourier series, the Fourier integral and finally the Fourier transform. Included will be a brief discussion of analysiswindows, including the box and Hamring windows."

Jan 1, 1998

By Ray Jambakhsh, John Okell, Frank Cook

"In early 1988, an experimental study was carried out at the Inco's McCreedy West Mine inLevack, Ontario. The objective was to develop blasting techniques which would allow themine to maintain production targets and reduce blast induced vibrations and overpressure.Due to its close proximity to the town of Levack (approximately 900 feet), particularconcern was expressed as to the vibration and overpressure resulting from the undergroundblasting operations."

Jan 1, 1993

By Robert Hopler

Earthquakes, ground vibrations, seisms, or whatever you want to call the shaking of the earth, have been a fact of life throughout time. In spite of this, most people (except those unfortunate enough to live in seismicallyactive areas) have probably never felt this phenomenon, or if they have, only a very few times in their entire lifetime. However, when it does happen, nothing is more frightening than the sudden shaking of the earth beneath us - after all, we think of the ground we walk on as the unyielding, solid underpinning of our existence.

Jan 1, 2006

By Kenneth Eltschlager

Business says that location is a primary component of being successful. So too is the importance of location in blasting. For blast seismograph data to be useful, the location of the blast and seismograph must be clearly documented. Another location of importance is that of a nearby structure. Establishing the spatial relationships between the blast, seismograph and nearby structures, allows the blaster to correctly interpret the data, evaluate the performance of the blast and gauge the validity of any complaints.

Jan 1, 2004

By Bobby Dupree

I remember a big problem with a seismograph in the winter two years ago. In response to a citizen’s complaint I placed a transducer near the corner of a two-story home. It was a pretty nice day for the winter months, the people were pleasant, and I had no problems digging a hole to place the transducer.

Jan 1, 2004