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By R R. Dimock

A goal of all mine operators is to optimize the breakage of the inplace rock to achieve maximum excavating efficiency. The use of the seismograph at Kennecott Copper Corporation's Nevada Mines Division, open pit mine in Ely, Nevada, has demonstrated that optimum blastability can be predicted by knowing the seismic velocity of the inplace rock. The relationship of seismic velocity to the quantity of the explosive required to achieve adequate breakage of the material can be determined. Once quantified, this relationship can be used by the mine operator to obtain the optimum drill pattern and powder factor for breaking the material to be excavated. A substantial savings in primary and secondary drilling and blasting costs can result from using the seismograph for blastability determination.

Jan 1, 1976

By Thomas Bakley, Rob Lee, Jay Rodgers

The present state of technology in Controlled Blasting uses standard explosives’ products to create a crack between holes along a desired line of break. The resulting pre-split, post-shear or cut line is often of variable quality with unwanted damage at right angles to the desired cut line. A new concept in Detonating Cord manufacturing has provided a radically different performing explosive. This new Cord has reduced the Velocity of Detonation by more than a third. It changes the Detonation Pressure proMe of Detonating Cord to a lower and longer sustained pressure pulse. In addition, it develops more gas than conventional cords. At the same time it maintains all of the handling and reliability advantages of conventional Detonating Cord.

Jan 1, 2001

By J R. Brinkmann, S G. Giltner

Nearly all of the South African gold mining industry still uses fuse and igniter-cord initiation systems. Over the past 30 years numerous attempts at developing new initiation systems have not yielded a viable alternative. New initiation systems for narrow stopes are currently being developed by various concerns and the likelihood of these efforts producing feasible alternatives is greatly improved due to the recent advances in electronics technology. The greatest potential benefit of alternative initiation systems is increased production rates through improvements in accuracy and reliability of firing over that of fuse/igniter-cord. Another important feature is the capability of millisecond delay firing as this can lead to reduced stope cleaning times by way of enhanced rock throw and improved fragmentation characteristics.

Jan 1, 1989

By Jim Daly

The word “Enron” has taken on a totally different meaning since its leaders were caught juggling the books, President Clinton’s reputation was destroyed not by what he did but by how he tried to cover it up, Martha Stewart spent time in prison for not being honest. Our society is tolerant of mistakes we humans make but has become very critical about what we do following those mistakes. The blasting industry is in a similar position. We have all heard the stories of the tree stump that came down through someone’s roof, of the windows that were broken, of the casualties that occurred when a blast was not properly guarded. What was done following these incidents? In the mind of the public, not enough.

Jan 1, 2007

By D T. Froedge

In 1972 the Kentucky State Legislature enacted House Bill 625 which was known as the Kentucky Blasting Law. This law was enacted primarily to stop problems associated with surface mining, but when it was enacted all industries using explosives were included. The bill was assigned to the Department of Mines and Minerals which created a Division of Explosives and Blasting. At that time, this division only had regulations concerning blasting. One should make a distinction between blasting regulations and other explosive regulations. Blasting is the actual use of explosives, the control of the blasting operation, how much is used, at what distances to buildings, the yardage, and other actions associated with the detonating process, explosives regulations generally including safety to the personnel and the storage of explosives.

Jan 1, 1977

By Dennis G. Wright

The Minister of Fisheries and Oceans for Canada is responsible, under the Fisheries Act, for the protection of all marine organisms and their habitats. The detonation of explosives in or adjacent to fish habitat has been demonstrated to cause disturbance, injury and/or death to aquatic organisms, and/or disturbance, destruction or alteration of their habitats. The Department of Fisheries and Oceans recognizes that the use of explosives may be the most practical or cost effective method by which to complete a project and has undertaken the development of a set of guidelines that will prevent or minimize the destruction of or disturbance to aquatic organisms and their habitats while at the same time allowing scientific and industrial users of explosives to proceed with their projects.

Jan 1, 1997

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 David E. Siskind

U.S. Bureau of Mines Report of Investigation 8507 was published in 1980. In a comprehensive analysis of all known blast damage studies plus new definitive data, the USBM authors adopted new safe level criteria of 0.5 & 0.75 in/sec for the frequency range corresponding to structure resonances. These were 3 to 4 times lower than the existing limit of 2 in/sec and are the most restrictive scientifically-based blasting criteria for the prevention of threshold hairline cracks in homes. The Bureau's own tests involved 76 homes in six states. In USBM RI 8507, those tests were combined with data from nine other studies from the US, Canada, Czechoslovakia and Sweden in an overall conservative summary analysis intended to preclude blasting damage.

Jan 1, 1998

By George P. Jr Schivley

Data is presented showing Penetration Rate (PR) versus Force-on-the Bit (FB) and Bit Angular Speed (N). Using this data, it is shown how FB and N each uniquely contribute to the PR for any particular drilling situation. This data represents many mining situations; including coal, copper, gold, iron ore and limestone quarrying. The important relationship between Penetration per Revolution (P/R) and the height of the cutting elements of the bit (CH) is discussed. Drill performance is then reviewed, considering the effect of FB and N on bit life. All this leads to recommendations for the operating values of FB and N for drilling situations where the rock is not highly abrasive and bit replacements are because of catastrophic failure of the bit cone bearings.

Jan 1, 1995

By Ron J. Elliott, David G. Otto

This project involved deep blast densification of recent volcanic avalanche debris deposits consisting of a 43 meter thickness of loose clean to slightly silty sand, gravel, cobbles and boulders deposited as a result of the 1980 eruption of Mt. St. Helens, Washington, U.S.A. This project was carried out to enhance the resistance to liquefaction or dynamic settlement of soil deposits under the bridge abutments for construction of the 59.4 meter long South Coldwater Creek Bridge. As this bridge is located close to the Mt. St. Helens fault, it will in all likelihood be subject to earthquakes in the order of 6.5 with expected accelerations of 0.55g. Without soil densification, the bridge would suffer severe structural damage in the event of a significant earthquake.

Jan 1, 1994

By Robert Hopler

In part one we discussed a Chinese seismoscope allegedly invented and used in the year 136 (or 132, depending on the source). Interestingly, historical references to the measurement of earth movements then seem to be nonexistent until up into the 1700’s. There could be two explanations for this hiatus: first, that there were no earthquakes in the world for 1600 years, or, second, the “Dark Ages” really did exist, where intellectual inquiry and all sorts of learning came to a halt. Of course there were earthquakes, so the explanation for the lack of a record of invention is the reality of the Dark Ages. explained is the fact that the Dark Ages ended in about A.D. 1000, but that is beyond the scope of this story.

Jan 1, 2006

By Edward J. Walter

Our modern technology is provided with a unique but flexible power tool in the use of explosives. A by-product of explosives usage is vibration or elastic deformation of the earth which is annoying to the ordinary person and can be damaging to structures. The problem is not new, it is more than fifty years old. Adequate vibration standards have been developed so that blasting programs can be properly planned and safely executed. Changes in our social culture have somewhat changed the emphasis in blasting vibration from damage considerations to the much lower level of citizen annoyance. Vibration codes based on this level will be highly restrictive and prohibitively costly. Cooperation is urged between operators, community officials, agencies at all levels,and consultants to see to the development of sound realistic vibration codes.

Jan 1, 1975

By Michael M. Jackson

"The mining industry has for some time compared explosive energy requirements to theresults obtained using ANFO. Drill patterns, powder factors, and explosive bulk strengthshave all been developed based on the detonation characteristics and blasting resultsexhibited by ANFO. However, there are some mining applications where the use of ANFOcan cause over_blasting if loaded to acceptable collar heights or surface breakage problemsif collar heights are reduced. A specialized, low strength, low density water gel explosivehas been developed that has loading densities in the range of 0.4 to 0.7 g/cc. The uniquecharacteristics of the low density water gel explosive is that the explosive can beformulated with a range of available bulk strengths while maintaining excellent detonationsensitivity for use in applications involving ore/waste control, restricted blast patterns,small bench heights, etc. The"

Jan 1, 1993

By Jim Daley

SEE is a dynamic organization composed of people from all facets of the explosives industry who are truly interested in the advancement of that industry. I had been a miner at the Homestake Gold Mine in Lead, SD for 12 years when I decided to obtain a mining engineering degree. The mental and economic consequences of that decision were more severe than we had imagined. The joint scholarship program of the Northern Plains and Black Hills Chapters of SEE provides assistance to several college students each year. I was fortunate enough to receive scholarships from this program twice and this assistance helped me and my family with both monetary and psychological support during times of need so that we could stay focused on the goal of obtaining a degree.

Jan 1, 1995

By J. Schoonover, A. Moore

In the explosives industry, individuals face a multitude of hazards while working in mines, quarries, and construction sites. Safety becomes an ever-present driver as companies attempt to control costs, promote quality service and products, and grow business all while ensuring employees return home safely every day. One of the most challenging hazards that threatens the goal of absolute safety is flyrock. Ensuring that a blast does not result in rock leaving the blast area, thereby creating a danger for personnel in the vicinity, can be complicated due to the multitude of factors. Shot design, geology, operational procedures/techniques, explosive products, security plans, communication methods, and drilling practices can all adversely affect the safety of individuals helping execute a blast through an increased risk of flyrock. Flyrock can also pose a major threat to the public and other non-blasting personnel in proximity. Like many other industries encountering various challenging hazards, the explosives industry has recently adopted innovative technologies to help mitigate the risk of complex hazards such as flyrock. Specific applications of Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, employed in the explosives industry can help reduce the likelihood and severity of a flyrock incident. This paper explores a case study and theories of how the integration of drone technology within blast security plans, mine planning, blast design, design auditing, and blast area clearance procedures can help to decrease the risk of a flyrock event through the provision of data and information previously unavailable. Multiple opportunities exist during a blasting operation to gather data using drone technology. It is these data-gathering opportunities that can be leveraged to be maximally equipped for the mitigation of flyrock. Better data from drones can be sourced and used in security plans and clearance measures as well as utilized during mine planning and blast design. Increases in the quality and quantity of information during these crucial steps of blasting has proven to be an effective way to increase the peace of mind for explosive end users. This peace of mind, along with design flexibility and adherence to performance, is why the integration and utilization of drone technology is key for effective flyrock risk reduction

Jan 1, 2024

By Peter Moser, Michael Messner, Florian Bauer

The existence of ammonia in underground blasting fumes was frequently measured in various field tests (6, 7). Ammonia in fumes with a TLV (threshold limit value) of around 30 ppm (slightly different in various countries) is a toxic gas but not considered to be a high risk for the underground work force as ammonia smells very itching and is extremely annoying. This might be the reason why ammonia is hardly measured in routine underground blasting fumes control. Another reason for the lacking measurement might be the circumstance that ammonia is a very reactive gas and the ammonia sensors available on the market are very cross sensitive to other gases like carbon monoxide. Nevertheless, especially since the introduction of bulk emulsion explosives in underground blasting, complaints from miners about ammonia in the blasting fumes increased. Research work by various institutions [8] around the world relates the ammonia in the fumes back to various mechanisms. Amongst others these comprise: a) non ideal (low temperature) detonation of explosives, with NH3 in the reaction products; b) reaction between rock and non detonated bulk explosives (especially when the rock is of a basic nature (high pH value); c) reaction between shotcrete and non detonated bulk explosives. Numerous blasting tests in an experimental underground set up have been made in order to check these hypotheses for ammonia origin in blasting fumes. None of them has been found to be responsible for sometimes high concentrations of ammonia in the fumes. The major reason for ammonia concentration in blasting fumes has been found in mine water of a high pH value (either natural or from using shotcrete). The mechanism identified is as follows: the moment a non detonated ammonium nitrate bearing explosive comes in contact with mine water of a high pH value, ammonia is formed immediately. The source for the undetonated explosive is twofold: firstly there is a certain spillage of explosives when the holes are charged (especially when using bulk products) and secondly not the entire explosives detonate completely. These undetonated remaining of the explosives end up in the muck pile after blasting. In case there is water of a high pH value the reaction between the explosives and the water starts immediately. This explains also the observation why ammonia can be measured in the blasting fumes quite a long time after the blast. The majority of the ammonia is not formed during the detonation; it is formed inside the muck pile even a considerable long time after the blast.

Jan 1, 2010

By BernardThierry

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts. This new type of model enables us to concurrently simulate the fragmentation of the rock, its movement and the associated seismic levels, all within a few minutes, which is a time compatible with a production cycle. Due to the complexity of the model, this article reveals the main principles and compares the results of simulations with on-site measurements in various sectors, i.e. quarries, mines and tunnels.

By R E. Langston, S M. Gazioglu

A preconstruction inventory program was conducted to determine the existing conditions of residential, non-residential and all other structures within 2,000 feet of the blasting limits for a highway excavation site in Asheville, North Carolina. Prior to major production blasting, eleven test blasts were detonated to establish site specific propagation parameters in order to develop contours of maximum allowable explosive charge weights per delay. The method of scaling distance by the square root of charge weight per delay was utilized in developing the contours of allowable charge weights. The charge weight contours were revised during blasting operations as additional vibration data became available. The effects of blast induced vibrations on a nearby water storage reservoir, a nearby vehicular tunnel and other adjacent residential and non-residential structures were observed and monitored over a period of two years of blasting operations.

Jan 1, 1980

By Cam Thomas

"Reflectorless laser survey equipment has made it much easier to take accurate measurements toinaccessible locations in quarries, open pit mines and rock slopes. Prior to the introduction of thereflectorless laser as a working tool, it was not possible to directly measure to inaccessible locations on rock faces. If a person could not occupy the point, only indirect measurements could be made. For blasting work, measuring the burden in front of the first row of holes could only be done approximately, using such techniques as holding a plumb line in over the crest, triangulating in on a few points or “eyeballing” the burden. This led to direct and significant problems with blasting, including flyrock and airblast (caused by insufficient front row burden), excessive vibrations, problems with oversize and tight digging (all of which may be caused by excessive front row burdens)."

Jan 1, 1999

By G. Walsh, L. Wolkovitch, A. Savage, V. Romero, T. Zimmerly, G. Imahara, J. Hyneman, K. Byron, D Tapster, S. Belleci, J. Metzger, M. Stanley

Testing was conducted at the Energetic Materials Research and Testing Center for the MythBusters on three separate occasions. This testing included (1) an experiment designed to create diamond from graphite using the shock and pressure of a detonation, (2) the flattening of a car using a steel plate driven by a rocket sled, and (3) the bifurcation of a car also using a rocket sled. All tests were successful; diamond was produced following the detonation of ANFO, and extracted from a graphite / cobalt matrix. A plate was accelerated to 646 mph (1040 km/hr) using a two-stage sled system loaded with 5” (12.7 cm) high velocity aircraft rockets (HVAR) into a car, which was subsequently demolished. Finally, a steel wedge was pushed to 541 mph (871 km/hr) by a one stage sled using HVAR rockets, and was able to cleanly cut a target car in half.

Jan 1, 2010