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By Weiying Zeng, Shouwei Wang, Jinbei Zhong, Xiangdong Meng, Lingtian Meng

"Due to a drainage problem, the Lanzhou to Chongqing high-speed rail line had been out of service during the 2015 wet season, so a drainage tunnel is to be constructed for the line and required to be accomplished before the 2016 wet season. This drainage tunnel is only 5 meters below the line which is in service, therefore blasting vibration needs to be strictly controlled. This paper introduces all theapplied blasting methods, parameters and detonation throughout the entire project, finally bringing in the electronic detonator stagger phase technique and corresponding time difference for detonation."

Jan 1, 2017

By Douglas R. Simms

O & G Industries, Inc. owns and operates a number of rock quarries within the State of Connecticut. These rock quarries are surrounded by residences and commercial neighbors who have concerns related to blasting. In addition, local commissions which issue the mining permits to O & G are required to hold public hearings, prior to issuing the annual permits each year.

Jan 1, 1994

By Peter Dare-Bryan, Will Hunt, Lee Julian

It is well-known that blasting has an economic effect on grade control activities. However, until recently, methods did not exist for measuring the grade control value change caused by the blast. Rules of thumb were the best method to minimize ore loss and dilution, as simulation has been traditionally constrained by time and computer power. Even with these rules followed, an extensive study performed on over 150 blasts showed that the value change caused by the blasts followed a normal distribution – some blasts created value, and some blasts destroyed value. The question naturally asked was “How can we ensure the blast designs are optimized to create value?” Recent advancements in computer power have enabled real-time blasting simulations that create post-blast grade control models before the blast is fired. Understanding what will happen before it happens allows blasters and grade control personnel to iterate designs, searching for the highest value achievable.

Feb 6, 2023

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 Peter Moser, Finn Ouchterlony, José A. Sanchidrián

"Blast fragmentation data in the form of percentile fragment sizes as function of specific charge oftenform a set of straight lines in log(size)-log(energy) space that tend to converge on a common focal point.Single-hole shots in specimens of virgin material clearly show this and the phenomenon is called the fragmentation-energy fan. Field data from bench blasting in rock scatter much more but may be interpreted to form such fans. The slopes values of the fan lines depend primarily on the percentile level. This property can be derived from sieving functions of the form P[ln(x/xmax)/ln(xmax/x50)]. An example is the Swebrec function when the parameter b is constant."

Jan 1, 2017

By T Duff

This paper describes results from small scale tests conducted to determine the distribution of pressure on target plates when subjected to loading due to the detonation of a buried mine in various media. The tests are conducted by using saturated sand, dry sand, and water as the loading media. Different stand-off distances are investigated. Kolsky bars and pressure sensors are used to determine the free-field pressure - time profile of the output of the charge at any location on the vehicle bottom. For verification of the pressure results at certain distances, the specific impulse measured by utilizing different size round plates are employed. In order to investigate the loading mechanisms, high speed cameras are applied. The small-scale test results can be scaled to full scale by using verified scaling laws.

Jan 1, 2014

By John W. Brown

"Adequate dust control in and around rock drills is a problem that must be solvedfor the health and safety of workers running the drill as well as those working around thedrilling operation This paper will discuss the designs available from most drill manufacturers todayand the effort ‘nvolved in keeping them effective on a productive basis."

Jan 1, 1999

By Kyle Apple

The following is a case study of how LuckStone Corporation improved their blast monitoring and documentation program. A number of resources already at their disposal have been utilized to improve the body of data collected from each blast. The tools being used include GPS, aerial photos, and a user-friendly push button format excel spreadsheet. The data collected include product by product records of materials used, distances to all concerned neighbors, seismograph data, etc: The spreadsheet has been designed to perform an ongoing analysis of blasting trends. The program has been carried out at a corporate level and is in use by blasters at each location. This paper addresses the advantages and drawbacks of this program. It also addresses the ways in which the various tools were integrated, Discussed as well is the need for simplicity when bringing “new” technology to the field and the steps taken in familiarizing the end user to changes.

Jan 1, 2001

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 Deepesh Yadav, B. S. Choudhary

Underwater drilling and blasting is conducted for deepening of sea channels for port berths, lake or reservoirs for water supply etc. so that rock dredging becomes easier. During this process there are several associated unwanted effects having potential to cause damage to surrounding structures and the environment, flora and fauna. Though all these ill effects can’t be completely eliminated but adopting controlled blasting techniques can minimize these to tolerable levels. It is recognized that ground vibrations resulting from rock blasting below water near dam may endanger the safety of earthen dams. Therefore, controlled blasting technique was used to ensure the safety of dam and its efficacy was established by monitoring of blast vibrations. The usage of small quantity of explosives confined in blast holes, non-electrical delay detonators and initiating each hole with a separate delay helped to minimize the ground vibration effects on surrounding structures.

Jan 1, 2018

By Dale Preece, Joergen Pilz, Zavis Zavodni

An overland conveyor was constructed at a surface coal mine to reduce the truck haul distance and make the operation more efficient. An important element in this system is a truck dump facility to transfer coal from truck to conveyor. Mechanically stabilized earth retaining walls were employed to accommodate the coal processing equipment, including the crusher, in this facility. These retaining walls are close enough to the pits being mined that blasting induced vibrations must be considered in analyses of the wall structural stability.

Jan 1, 2010

By Raj K. Rajamani, Solomon A. Tucker, Michael K. McCarter

"In a study aimed at exploring possible improvements in operating performance at an Open Pit Copper (OPC) mine in the western U.S., the impact of blast energy changes on crushing performance was evaluated. OPC feeds its 3-stage crushing plant in 12-hour-day shifts with skarn ore from three domains: Pit_B (B), Pit_S Low-Grade (SLG) and Pit_S High-Grade (SHG), in the blending ratio 1:1:1 (B/SLG/SHG). Thecrushed product is fed to a 2-stage ball mill circuit. "

Jan 1, 2017

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 Behrouz Ohadi, Kamran Esmaeili, Bibhu Mohanty

In most metalliferrous open pit mines with heterogeneous orebodies, blast-induced rock movement is a crucial outcome that has unfavorable impact on ore and waste segregation in the post-blast muck pile, resulting in either ore loss (the ore is misclassified as waste and sent to the waste rock dump) and/or ore dilution (waste is misclassified as ore and sent to the processing plant). While many studies have been carried out to assess the influence of blast design parameters on blast-induced rock movement, the influence of rock mass characteristics in these studies have been overlooked.

Jan 1, 2018

By Patricio González Santis, Jacopo Seccatore

This paper documents drilling and blasting activities from gold mining in Ecuador and Chile. First, are described the outdated and often non-rational techniques employed by miners, to provide a general framework of the current methods. Then, it is shown what can be improved and how the current methods can be modified. Finally, are shown some field applications and the comparisons of the results obtained

Feb 1, 2020

By S. Hosein, W. Birch, C. Johnson

The widespread adoption of electronic detonators has given rise to the development of linear superposition to control the environmental impact on both third-party properties and residents resulting from blast induced vibrations. Linear superposition has become a very effective tool in the hands of blasting engineers and has enabled aggregate reserves to be accessed that once had to be abandoned. This in turn has resulted in more and more complex blasting pattern to be developed that contain multiple rows and multiple decks all with different maximum instantaneous charge weights of explosives. This is then made more complex by having to consider multiple sensitive locations often with different Peak Particle Velocity vibration limits. This paper is a case study of what did happen when a blast was designed that “pushed the boundaries” of environmental blast vibration design and control, without taking fully into account the fundamental geophysical properties of seismic waves. The resulting blast design caused a greatly enhanced s-wave to be created in a critical direction from the blast pattern. The root cause being the s-waves from earlier detonating decks in the blast pattern arriving within 2 milliseconds of decks detonating later in the blast pattern. 209 individual decks were fired in the blast pattern of which 41 pairs of decks arrived at the observation location less than 2 milliseconds apart when taking into account the s-wave speed and direction. The lesson to be learned when using electronic detonators to limit ground vibrations from complex blasting patterns, is that it is just not good enough to look at the planned firing times, a professional blasting engineer must also understand the likely interaction of the various seismic wave types created and their combined impact on any given monitoring location.

Jan 1, 2024

By Kaushik Dey

Bord and pillar is the most predominant method of wining of coal in Indian underground coal mines. Development heading in coal mines often encounters roof stability problem and results in roof overbreak. Research on this reveals that the blast-induced ground vibration may have significant contribution in roof overbreak, especially, when solid blasting is carried out in the bord and pillar method. Solid blasting, in general, is associated with higher charge confinement due to lack of free face and generates higher ground vibration, which in turn results in excess overbreak.

Jan 1, 2008

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 Dale Nies

In the past, cap and fuse has been the only economical and efficient initiation system capable of providing sequential timing, ease of loading and hookup, and unlimited borehole number for backstope rounds. Unfortunately, in spite of these advantages, several negative factors inherent to the system have always been noted. Due to the long, narrow nature of backstope rounds at the Sunshine Mine, the cap and fuse system results in very long, inaccurate delay times. The system was also occasionally unreliable under all the conditions encountered, which in turn could cause potential safety hazards.

Jan 1, 1989

By Gustavo Huerta Valer, Jorge Cárdenas Miranda, Johan Salas Flores

One of the challenges of mining is the optimization of the blasting process, which has an important impact downstream in the processing of crushed ore in the plant, that is why mining companies ensure the results of granulometry obtained from the blasting process through a joint work with companies specialized in the process of loading with explosives.

Feb 6, 2023