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By Ulrich Leiste

If the iron ore loss is 15% in the process of mining, the total iron ore loss in the world will be about 461 million tons, this is equal to the total production of 230 iron ore mines each of which produces 2 million-tons of iron ore per year. Based on a series of blast tests in the Malmberget mine, this paper shows that ore recovery can be markedly increased by improving blasting technology such as choosing a correct primer position and making use of shock wave collision. The paper further suggests that a high ore recovery can not only reduce natural resource loss and mining cost but also prolong the life of a mine. In addition, the paper shows an example of reducing blast-caused rock damage in the roofs and walls of underground drifts (tunnels) by using new blasting methods in the Malmberget mine. Finally, the paper shows how the Malmberget mine has successfully reduced the ground vibrations, without adversely affecting fragmentation and ore recovery in sublevel caving mining.

Jan 1, 2014

By Cathy Aimone-Martin, Frank Achuff

The New Mexico Department of Transportation (NMDOT) and the Federal Highway Administration (FHWA) have let a contract to Sierra Blanca Constructors for a design / build contract along 38 miles US 70 in Lincoln County, New Mexico. The project will improve safety of travel along the corridor and facilitate the adopted economic development goals of the state. Proposed improvements include widening the existing highway from two lanes to four lanes, providing left turn lane options at selected locations, improving access for businesses and residences, aesthetically enhancing retaining walls, improving storm drainage and replacing the existing pavement with a 30 year mechanistic imperialistic perpetual pavement design. The US 70 Hondo Valley highway project is situated in a narrow valley with steep limestone walls, passes along a Scenic Byway and numerous historic ranching communities with structures that date back three centuries. The scope of work included requirements to monitor and mitigate blasting, noise, and vibrations. The contract was very presumptive with regard to blasting design and procedures. These included visual impact mitigation to treat and stabilize slope cuts, the Migratory Bird Treaty Act protecting roosting and nesting birds from airblast, and the protection of historic and cultural features such as acequias, wells, and structures. Public involvement affecting the rock blasting design has come from citizen task forces and committees concerned with highwall aesthetics and preserving the scenic byway and cultural resources. Constraints placed on the blasting program from agencies and the communities are often at odds. For instance, blasting must produce stable yet natural-looking walls to preserve aesthetics. Restrictions have been placed on pre-splitting and smooth-wall blasting yet safe slope are of the highest priority. This paper presents details of the design/build process undertaken by the contractors to conduct blast rock in an environmentally sensitive region. Blast designs consistent with good construction practices and used to comply with the many federal and state highway stipulations are described.

Jan 1, 2004

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

By Jorge Cárdenas, Piero Mejía, Diego Gamarra

The present case study details the solution to a complex situation in a mining operation, involving the challenge of expanding the tailings storage facility in high-criticality areas adjacent to electrical rooms that provide continuous power to the entire mining process, including water pumping and drainage systems. For this purpose, blasting is required to prepare the construction areas for the new expansion facilities. Upon deciding to proceed with blasting, a comprehensive engineering assessment was conducted to ensure operational continuity without impacting the process, while generating sufficient fracturing in the rock mass to allow extraction with auxiliary equipment. Support from specialists through the Technical Assistance area was requested, and a detailed evaluation was carried out through advanced studies. Field vibration studies were conducted to define attenuation models and characterize the rock mass in the sector. With this information, simulations were carried out using predictive and probabilistic models with Monte Carlo methods to select delay charges and optimal timing for reducing vibration levels and increasing frequency levels. With these measures, the three blasts conducted near the Gas Insulated Substation room, which had distances ranging from 30 to 100 meters, produced the following results: • Vibrations; The three blasts conducted at distances of 100, 30, and 50 meters recorded vibration values of 5.3, 40.2, and 9.5 mm/s, all of which were below the maximum vibration level of 50 mm/s set by the projects area. According to the USBM RI8507-OSMRE standard, all values for Peak Particle Velocity (PPV) and frequency were below the permissible limits. • Flyrock; Through filming and post-blast inspection, it was confirmed that the ejections were within the safety zone. • Fragmentation; The results obtained showed a maximum overbreak size of 1.5 meters, allowing the broken material to be moved effectively.

Jan 21, 2025

By Paul Ross, Harry Burchett, Lou Case, Calvin J. Konya

"The Cumberland River in Harlan, Kentucky has flooded the town for numerous years. TheU.S. Army Corps of Engineers funded a project to divert the river. The project consisted oftunneling through a mountain to divert the river. The approaches to the tunnels requiredcontrolled blasting to create noses to help channel the water and debris into the tunnels.The geologic structure was such that conventional presplitting techniques were notproducing the desired results and were causing severe backbreak. Replacement of the rocknoses with concrete would cost about a million dollars; and therefore it was important tosave them if at all possible. Blasting techniques were developed which allowed the projectto be successfully completed. This paper will discuss the case history of the controlledblasting procedures."

Jan 1, 1993

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 Ali Kahriman, D. Adiguzel, R. Ulger, U. Akkaya

The environmental problems arising from ground vibration has been faced and discussed frequently in various industries such as quarry, mining, civil works, shaft, tunneling, pipe line and dam construction etc. where the blasting operations are unavoidable. This paper presents the results of ground vibration analysis induced by blasting during the construction of the Istanbul Kadiköy-Kartal metro tunnel. Different rock formations in this tunnel route which is 21.6 km in length were encountered during the excavation process by blasting. As a first stage, Hoek’s Geological Strength Index (GSI) values of rock units were determined by using inverse distance weighting method. The GSI values which were obtained from boring data were used when evaluate the data. GSI values were estimated by inverse distance method (figure 3) along with the tunnel route. Afterwards, ground vibration parameters induced by 21 shots which were made in different locations was monitored and passing routes of vibration waves determined. Weighted averages of GSI values were calculated according to distance of the regions where vibration waves passed. Multi regression analyze were made with using frequency, charge per delay, GSI and the distance between the shot point and monitor station. The main goal of this study is to investigate the relationship between ground vibration frequency induced by blasting and GSI.

Jan 1, 2011

By Travis A. Davidson, Ralph E. Burnham, Cathy Aimone-Martin, J. Kelly Ratliff

Blasters face a long list of tasks to execute daily—from vehicle inspections to blast design and layout, hole loading and tie-in, securing the site, and finally, safely executing the blast. Good practices and, in most cases, regulations and requirements necessitate documenting their work, specifically their blast report. While some blasters use paper forms, others use electronic means to streamline the process. The authors have served as attorneys and expert witnesses in representing companies and individual blasters in numerous administrative and legal matters in which documentation of the blaster’s work was both critical and detrimental to the effectiveness of defending their work. This paper discusses in a case-study manner the authors' observations concerning good blast report format, specific observations around electronic and paper report completion, record-keeping, seismograph setup and recordkeeping, video and photo documentation, internal auditing, and other topics related to documenting the blast. The paper aims to serve as a discussion guide for blasters to improve their blast record-keeping process, develop better practices that effectively document their work, and allow them to defend their work should a claim arise concerning their operations.

Jan 21, 2025

By Michael Wieland

The thrust of this report is to overcome some of the technical deficiency in the scientific methodology that correlates the work output during a charge explosion to the resulting toxic fumes. Thermodynamic work-principle models yield (undissipated) shock and heave results for shooting underwater and in rock stratum with related toxic fumes. Underwater circumstances yield reliable test data for the work process, though questionable or no fume results. Work-output measurements in rock shots remain difficult if not intractable, though some fume reports exist. Underground tests with thick-wall metal pipe bombs yield consistent toxic fumes trapped within the test chamber. The work output, rendered as fragment kinetic energy, can be inferred from the well-tested theory of R. W. Gurney, originally designed for military ordinance. Therefore a work-principle model for cylindrical pipe bombs was developed to predict fragmentation work output and reaction-zone fumes, permitting the double comparisons to reported and inferred results.

Jan 1, 2010

By Rolf R. Schillinger

Subject of the paper are blasting vibrations as sources of environmental molestations including acceptance level,complaint level and damage level as well. Besides, the subject shows a comparison of international regulations and their problematical aspects. In consideration of blast induced immissions the subject shows that human annoyance has become an important place in blasting works. It provides a solution proposal how to minimize environmental effects of blasting works.

Jan 1, 1996

By Lizbeth A. Escobar, Phol M. Llanos, Maritza Y. Avila

The present research develops the estimation of critical parameters such as the distances and times between holes to avoid failure due to dynamic pressure in electronic detonators based on the near-field ground vibration model of Holmberg & Persson and the hydrodynamic model of Neyman.

Feb 1, 2020

By J T. Patterson

The mining, quarrying and construction industries are often blamed for causing damage to residential-type structures when explosives are used. The claim experience for blasting vibration damage has been poor. This coverage is excluded from the Comprehensive General Liability (CGL) policy. To obtain this coverage, the policyholder must meet additional criteria and an additional premium must be paid. The risk management process offers the explosives user a technique for minimizing the risk of complaints and vibration damage claims on his insurance program and his cash flow. Case histories indicate that the vibration damage claims expense may be a lower risk than the risk of interference with production and cash flow. An annotated bibliography on risk management and defense of vibration damage claims is provided.

Jan 1, 1978

By Dale Preece, Steven Case, Cassidy McAllister

Simplot Phosphates produces high quality phosphate fertilizer through open pit mining. The operation near Vernal, UT began as a three-pass mining process carried out with drill and blast followed by the combined effort of shovel-truck and dozer material removal. The first two passes removed the overburden and the final pass mined the relatively hard phosphate ore for processing at the mill. Vertical blastholes were employed in all of the mining passes.

Jan 1, 2012

By Shadrack Nuamah, Erik Westman, Bright Afum, Jesse Addy

Rock fragmentation is the most critical aspect of hard rock production blasting due to its significant impact on drilling and blasting costs and the economics of subsequent loading, hauling, and crushing operations. This study analyzes current cost trends in the drill and blast operations of an anonymous open pit gold mine and proposes cost-effective drill and blast geometric parameters. The investigation focused on one operational pit with provided design parameters for two shots, shot 1 and shot 2. Existing blast parameters and two additional proposed sets of geometric parameters were evaluated using the Kuz-Ram and Chung and Katsabanis fragmentation models to estimate mean fragment sizes. The results indicated that the proposed blast parameters produced estimated mean fragment sizes within the mine’s desired range (not exceeding 45 cm). Additionally, the explosive energy was utilized efficiently per in-situ material blasted. The proposed parameters increased the estimated total volume of in-situ material fragmented by approximately 14% for both Shot 1 and Shot 2 compared to the current parameters. Furthermore, adopting the proposed blast parameters could lead to significant cost savings. The evaluated total drill and blast cost savings were approximately 11% for Shot 1 and 12% for Shot 2. These savings stem from the increased efficiency and effectiveness of the blast operations, highlighting the potential for substantial economic benefits. This study demonstrates that optimizing blast geometric parameters will allow open-pit mines to achieve desired fragmentation, utilize explosive energy more effectively, and realize considerable cost savings in drill and blast operations.

Jan 21, 2025

By Miguel Humpire Huamani, Gustavo Huerta Valer, Jorge C. Cárdenas Miranda

As part of the continuous improvement and increase productivity to achieve the mining and extraction plan of a low-grade open pit copper operation, alternatives are required to expand the blast pattern to maximize drills and steels resources along to ensure the fragmentation results for the process plant with volumes from 500k tons of broken material per day. Therefore, the application of aluminum based ultra-high energy explosives was an alternative to achieve the objective of expanding the production pattern by 34% while maintaining energy factors levels along with the distribution of explosive and the application of the pocket charge in the stemming level, reducing the load factor, maintaining the fragmentation results in P80 and increasing the percentage of fines less than 1.0 in (2.54 cm). An important development to ensure the supply and perform successfully blasthole loading was the implementation of a supply system with pre-blending (aluminized emulsion) which is stored in silos and load through factory trucks. In the field we ensured optimal initial and final density levels with chemical sensitizer to perform the most fracturing work in the rock, complementary evaluations were performed to predict flyrock and define safe equipment evacuation radiuses along with advanced vibration monitoring for the sustainability of the mine.

Feb 6, 2023

By Sandra K. Penttinen

A difficult blasting project can go very smoothly when every precaution is taken prior to and during the blasting procedures. These precautions include conducting careful preblast condition surveys of nearby structures, initiating a good public relations program prior to the beginning of the blasting, and following a good safety program during the blasting procedure.

Jan 1, 1994

By Ian Bell

This paper investigates fragmentation in an aggregate quarry using the fragmentation-energy fan concept. Six blasts were monitored, located one behind the other in the same quarry area. The rock structure was blocky, the water level and the usage of explosives were variable within and between the blasts. The powder factor above grade was between 0.28 and 0.44 kg/m3 (0.47 and 0.74 lb/yd3). Fragmentation of the plant feed was measured using an online digital image analysis system and three belt scales. The oversize material that was not directly fed to the plant after the blast corresponds to 3‒9.3 % of the total. Data from image analysis was used to build the size distribution in the coarse range (fragments above 120 mm), and the passing fractions at 120 and 25 mm (4.72 and 0.98 in) obtained from belt scales data were used in the range 120‒25 mm (4.72 ‒ 0.98 in) . The non-dimensional percentile sizes between 10 and 90 % for each blast are described through power functions of the powder factor above grade; the model coefficients are statistically significant. From them, using the principles of the fragmentation-energy fan and the Swebrec distribution properties, the fragmentation can be expressed in terms of the powder factor by means of five parameters: the fan focus coordinates and the three parameters of a function of the exponents vs. the percentage passing. The model shows a good capability to describe fragmentation.

Jan 1, 2019

By Jeff Wachendorf

As the title "Cast Blasting Around Town" implies, this paper details the starting of a cast blasting program in and around the town of Colstrip, Montana. As strip ratios have increased, the need to adapt and find solutions to provide coal at a reasonable cost to the captive power plants has risen. Colstrip, Montana has a long history of coal mining which dates back to the early 1920's when Foley Brothers began supplying coal strictly for powering locomotive engines. Early mining days starting in the 1920's and the progression up through the 1970's when mine mouth power plants were built will be discussed. To accomplish the desired results, early mining techniques included steam and electric powered equipment as well as a lot of actual horse power.

Jan 1, 2009

By Justus Deen, Paul V. Sterk

Through the 119 year history of the Homestake Mine various methods of raise mining have been used, these include conventional, bored, and drop raises. These raises provide passage for men and supplies, provide ventilation, transfer broken rock from level to level, and serve as emergency escapeways. As the 1980s came to a close, many of the larger ore bodies in the mine had been mined out. This has resulted in many crown pillar situations that required a method to mine them. In addition, the Homestake ore body also contains numerous ore reserves that have short vertical height. The ore itself can be from vertical to 50 degrees in dip. Due to the high cost of drift and ramp development many of these ore bodies are sub-economic using conventional mechanized cut and fill mining.

Jan 1, 1996

By Justus Deen, Paul V. Sterk

Through the 119 year history of the Homestake Mine various methods of raise mining have been used, these include conventional, bored, and drop raises. These raises provide passage for men and supplies, provide ventilation, transfer broken rock from level to level, and serve as emergency escapeways. As the 1980’s came to a close, many of the larger ore bodies in the mine had been mined out. This has resulted in many crown pillar situations that required a method to mine them. In addition, the Homestake ore body also contains numerous ore reserves that have short vertical height. The ore itself can be from vertical to 50 degrees in dip. Due to the high cost of drift and ramp development many of these ore bodies are subeconomic using conventional mechanized cut and fill mining.

Jan 1, 1996