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By Frank Hirthammer

Over the past few years, development and implementation of digital logistics solutions has convinced users of many additional advantages of this technology. Barcode labeling and reading increases the company’s efficiency and safety by reducing handwritten documentation and preventing misinformation. Sustainable information and productivity management is a significant advantage in competition. Since manufacturing information is tracked throughout the whole supply chain until the final consumer, all processes become transparent what ensures efficient risk tracking, correct disclosure to authorities (if required), and the compliance with company rules.

Jan 1, 2018

By Alastair Torrance, Gary Cavanough

Over the past two years a research project has been performed on reactive and hot ground. A key finding is that host materials including carbonates and coal are inhibitors to the reaction of sulphide and nitrates. The mechanism of this inhibition is pH buffering and isolating the surface of sulphide from reactants. It has been identified that acidity is a key driver of the reaction with a pH of 2 required for a reactivity event. A series of decomposition experiments confirmed that reactive and hot ground are essentially the same phenomenon with the heating produced either by the reaction of sulphide with nitrates or an external heat source. The results indicate that the key driver of detonation in reactive ground is energy and heat released from the acid induced reaction of sulphide and nitrate with no indications of sulphide being a catalyst or contributor to detonation apart from being a heat source. There must be sufficient sulphide and thermal insulation to provide and retain enough heat for detonation to occur. A pathway to detonation is postulated whereby the heat travels upwards and results in evaporation of water in the explosive. When the temperature reaches approximately 200°C (400°F) the ammonium nitrate starts to decompose, decreasing the mass of the reacting species. The material in the top layers has reduced density and specific heat hence the temperature of the top region rapidly increases up to >1000°C (1800°F) and may initiate detonation. Field tests on loaded blast holes support this proposed mechanism. Case studies are presented whereby the research findings are used to provide an analysis of historical reactive ground events.

Jan 21, 2025

By Chantale Doucet, Mario Paventi, Malcolm Scoble, Yves Lizotte

Laboratory studies in homogeneous material indicate that the area of new surfaces created by blasting is proportional to the energy imparted to the material. Field studies, however, show that fragmentation is also related to the rockmass structure. This paper reviews ongoing compilation of a comprehensive and integrated blasting database which is based upon field monitoring and laboratory testing. A priority application of the database is to support attempts to more fully understand structural control over fragmentation. Database construction and the relative importance of rockmass physical and mechanical properties are considered in the paper. A methodology for data collection prior to, during and after blasting is reviewed. Data summaries from three case studies of blast performance in surface and underground mines are presented. These illustrate various aspects of the methodology, which included image analysis to quantify the fragment shape and remnant geology evident in the muckpile as part of the evaluation of structural control over fragmentation.

Jan 1, 1994

By A K. Raina, P B. Chourdhury

Flyrock is the unwanted throw of rock fragments to excessive distances in opencast blasting. The incidence is relative in nature incorporating the distance of objects of concern like structures within and outside the mine, equipment within the mine & near the blast and persons within and off the mine. Several attempts to predict and defi ne fl yrock made worldwide could not address the problem since the phenomenon is not a regular feature in blasting. This probabilistic nature of fl yrock allows for risk calculation. CIMFR, India developed a Factor of Safety based risk criterion (10, 14) for evaluation of throw/ fl yrock in opencast mines that incorporates all the above in terms of distance and allowable limit of throw – which in turn determines the risk. The criterion provides the blaster a tool for mathematical evaluation of fl yrock risk in terms of a Factor of Safety and threat ratio (defi ned for the 1st time), thereby enhancing confidence when blasting. The method is easy to use and has been applied to several mines in India and the results are signifi cant. This paper details the evolution of the concept and its application in three limestone mines of India and the results obtained. The application of the method for defi ning a fl exible danger zone is also discussed.

Jan 1, 2008

By Winfried Rosenstock

AEBT has been available for a couple of years and is successfully applied in Australia. Up to now it was mainly used in coal surface mining at the Australian East- Coast. Presently, the proved results reach ~ 50 % reduction of Drilling & Blasting costs and a productivity increase of between 10 and 20 %. In 2003 it was for the first time used in surface metal-mining. The mine features for the time being an extremely difficult geological environment and had above to be carried out in the transition level waste/ore. Reductions of wall control, powder factor and vibrations were the main target.

Jan 1, 2004

By Jan Mehren, Arild Neby

Underwater Tunnel Piercing or Lake Tap, often also called the Norwegian Method, will in many projects be an important part of the hydro electric development scheme. The very last blasting round in the Lake Dorothy Lake Tap Tunnel, which penetrated into the lake at a depth of 120 ft (36 m), was such a key step in constructing the Lake Dorothy Hydroelectric Project. A lake tap project is multidisciplinary. Besides the pure blasting and construction technique aspect, engineering geological and geometric considerations that aim to optimize the tunnel alignment making a lake tap possible at minimized risk are of significant importance. Output data from numerical model analysis of the hydrodynamics resulting from the blasting is vital for the final adjustments to the geometrical layout. The planning of monitoring systems for the surveillance of hydrodynamic impact on valves and pipes as well as control with water levels and air pressures prior to and during the blasting, are all additional crucial elements in the design. More than 600 lake taps have been successfully performed in Norway since the 1890`s. The technique, which deserves to be called well proven, has been applied mostly in the hydropower sector but over the last 20 years also for shore approaches in the oil and gas industry. The demand for this technique seems to be ever more growing.

Jan 1, 2009

By Neal Lee

Reduced relief horizontally means an increase in energy expended vertically into the rock surrounding the stemming column, and potentially through the stemming column. The vast majority of holes in any surface blasting operation are afforded two horizontal relief faces at the moment of firing, whether by existing relief faces in front of and to one side, or previously blasted hole(s) in front of and to one side of the holes in question. When the energy expended in any hole on the blast pattern has less than two Horizontal Relief Planes or faces (referred to moving forward here as “HRPs”) available to it at the moment of firing, a higher percentage of the available energy is directed vertically. In the analysis of recorded videos by the author, one will note the fact that stemming ejection/flyrock is observed to a much greater degree from the center of almost all patterns when they are timed to “pull out of the middle” (“box cut" timed patterns). This is because the first hole to fire in each row has only one Horizontal Relief Plane, which significantly decreases horizontal avenue for energy release for these holes. This of course results in an increase in the amount of energy expended vertically. This paper proposes a novel methodology to modify the stemming to better use the explosives energy of each hole, while controlling side effects such as flyrock and airblast.

Feb 6, 2023

By Sean Cahill

The Blasting In the summer of 1999, a Southern California drilling and blasting company conducted blasting as part of the grading operations at the Highlands Ranch development in San Diego, California. Highlands Ranch was a new single family residential project located near older residential properties in the area. Blasting was necessary to remove indigenous meta-volcanic rock associated with the local geology.

Jan 1, 2003

By Paul Worsey, Barbara Robertson

In June 2007, Missouri Science & Technology (formally UMR) successfully held its 5th and 6th Explosives Summer Camps. The camps, which include substantial industry participation, have been an outstanding success with both the students and their parents. They have also spawned a large amount of local, state and national media attention, including NPR and an article in the New York Times on the 3rd of July 2007.

Jan 1, 2008

By W. De Graaf, C. Mkumbo

Bulyanhulu Gold Mine Limited (BGML) commissioned a project of sinking a Bulk Air Cooling Shaft during its programme to improve the ventilation system on the mine. As part of this project, a ventilation drift had to be developed and holed into the Main Shaft at 4920 Level. AEL Mining Services (AEL) were requested to provide a technical solution, which included monitoring of blast induced vibrations and to design drilling and timing plans to ensure blasting activities on the vent drift were conducted without disrupting the main shaft’s infrastructure.

Jan 1, 2011

By Raymond V. Adolphson

The introduction of a new explosive component in 1955-56, called ANFO, featured much safer, effective blasting characteristics when compared to dynamite, accompanied by a notable reduction in cost. These savings mounted as borehole diameter or depth was increased with ANFO volume subsequently enlarged.

Jan 1, 1983

By W. Fourney

In the late 70’s and early 80’s in conjunction with other oil and gas well stimulation studies, personnel from the Dynamic Effects Lab performed model testing to demonstrate the effectiveness of utilizing an open section of borehole just before a plug. We called the process stem induced fracturing. The open section beneath the stem was used to increase the pressure magnitude and spread out the duration of the pressure pulse. This technique was later utilized to by Frank Chiapetta (1) in the fracture and fragmentation of rock in quarry blasting situations. He called his technique air deck blasting. In fact, Frank found that the Russians had previously discovered the same technique. There is currently interest in utilizing air deck blasting with an open section of hole beneath the explosive at the bottom of the bore hole to better remove the toe in a fragmentation shot. This paper reviews the development of stem induced fracturing and then describes a series of model tests conducted to measure borehole pressure at points along a borehole when an explosive charge is detonated at the midpoint of the borehole. Tests were conducted in both stiff boreholes (aluminum) and less rigid boreholes (PMMA-Plexiglas). Pressure time profiles were measured at the charge site, midway between the charge and the bottom of the hole, at the stemming at the top of the borehole, and at the bottom of the borehole. Crack initiation sites and crack propagation were also determined in the PMMA models. Some high speed pictures were taken of the event in the PMMA.

Jan 1, 2006

By K R. Sharpe, A Davitt

CXA is currently evaluating, in co-operation with Inco Metals, a new idea in small diameter hole blasting - the Unidelay Nonel initiation system. In concept, the Unidelay system is a hybrid of the conventional multi-period Nonel system and the safety fuse assembly/igniter cord system. It combines the operational advantages of the latter, simplicity and flexibility, with those of the former, safety and compatibility with all commercial explosives.

Jan 1, 1982

By David Yanez

The hydroelectric project "El Cajón" is currently under construction in the state of Nayarit, on the Santiago River, in western Mexico. This project is comprised of a Concrete Face Rockfill Dam (CFRD) with a rockfill necessity of 10,5 million cubic meters and it reaches a height of 188 m. The generation equipment includes two turbines with a total installed capacity of 750 MW.

Jan 1, 2006

By M. Szumny, P. Mertuszka, K. Fuławka

Multi-face destress blasting is the basic method of reducing rock bursts hazard in Polish copper mines. Blasting operations of this type are carried out regularly, twice a day in order to minimize the geomechanical threat while maintaining high extraction efficiency. Unfortunately, the assessment of the effectiveness of this type of work until recently was based solely on determining whether a given destress blasting triggered a seismic tremor or not. Information on the characteristics of seismic waves generated by blasting has so far been omitted in analyzes of this type. The lack of reliable knowledge about the generated seismic effect makes the introduction of constructive corrective actions impossible, which in turn significantly reduces the triggering potential of conducted destress blasting. This study presents the results of comprehensive work aimed at increasing the effectiveness of active rock burst prevention in Lubin underground copper mine. For this purpose, an innovative system for continuous monitoring of seismic waves induced by multi-face blasting was developed, and a new method for seismic assessment of the effectiveness of the destress activities was developed. Based on the monitoring data and the comprehensive analysis of waveforms, the effectiveness of individual blasting operations was determined, and on this basis, modifications to the drilling and blasting patterns aimed at increasing the generated seismic effect were proposed. The use of innovative methods of monitoring and data analysis made it possible to increase the effectiveness of the conducted activities, in terms of the magnitude of seismic vibrations, up to 250%. It should be emphasized that the introduced modifications were aimed at increasing the effectiveness of blasting operations while maintaining the current level of costs. As a result, the proposed solution turned out to be highly effective, significantly affecting the safety of the work carried out in Polish copper mines. Thus the proposed approach is planned to be implemented in other Polish copper mines belonging to KGHM in the near future

Jan 1, 2024

By Peter P. Harvey

The Nonel Primadet is a non-electric delay blasting cap initiation system. The most recent field application of the system in the Southwest has been at the Magma Superior Mine, Superior, Arizona.

Jan 1, 1978

By William E. Hill

The blasting program at the Valdez Creek Placer Mine must deal with challenging situations throughout the year. During the short summer, extreme water conditions must be confronted, while the winter months present problems of a different nature, where the overburden freezes to a depth of up to 18 feet. These obstacles require techniques borrowed from hardrock blasting combined with creative experimentation to overcome.

Jan 1, 1994

By John W. Kopp

The U. S. Bureau of Mines investigated flyrock and burden movement from blasting at several limestone and basalt quarries in the upper midwest. Blasts have been studied at 14 different sites using high-speed cinematography. Blasting was accomplished in 75- and 150-mmdiameter holes using a variety of explosives. Films from each blast were analyzed to show burden velocities, observed flyrock distance, and direction of throw in relation to the shot layout. This technique, in some cases, allowed determining point of origin and cause of the flyrock as well as the flyrock range.

Jan 1, 1994

By Mauritz Kotze, Jason Furtney, Ewan Sellers, Sandy Etchells, Tom Szendrei

The development of a simple model for gas flow and burden movement has driven the need to improve our understanding of burden breakage mechanisms for single hole blasts and the interaction between multiple holes in solid and jointed rock masses. Conventional analytical understandings of the burden breakout using the elastic-tensile fracture model were studied and found to provide a breakout angle that is independent of burden in contradiction to experimental data. By considering rock fracture in terms of Mohr-Coulomb plasticity using analytical expressions from the field of cavity expansion analysis an improved relationship between breakout angle and burden is derived until the point of critical breakout at which the angle of breakout suddenly changes from between 90 degree and 100 degrees to zero. This suggests that the critical burden occurs at about 0.6 times the radial fracture zone calculated from the analytical solutions.

Jan 1, 2013

By Clayton Thompson

Linear detonation wave generators (DWGs) shape a detonation wave so that every portion of the wavefront reaches the target “line” simultaneously. A projection-type linear DWG uses Gurney plate velocity predictions and Taylor deflection angle predictions to estimate the angle at which a thin projected flyer (typically metal) will impact a target. A mousetrap-style planar DWG consists of two projection-type linear DWGs working in succession to create a planar wave-front through shock initiation of each successive target explosive. The angle of deflection is critical to yielding a planar or linear wave profile. Gurney predictions, nominally accurate to within 10% of empirical results, may not yield ideal linear or planar detonation behavior when used with a grazing projection-type DWG, which typically requires accuracy within 2%. Simulations were conducted using AUTODYN hydro code to compare deflection angle prediction methods. Ranges of minimal error between Gurney and Taylor predictions and the results from the hydro code were determined, using PBX-9404-driven polyethylene flyers.

Jan 1, 2011