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By Peter G. Bellairs

The traditional concept of Optimum Drill and Blast is that it is achieved when ore is produced at the lowest unit cost and due to the complexities of most mining operations represents a band which extends either side of an overall cost minima. The above definition implies that Optimum Drill and Blast is static and once blasting is within the band around the cost minima then the process is optimised. However mining operations are not static with many events both long and short term impinging on the cost structure and productivity.

Jan 1, 1995

By D Linn Coursen

Detonation propagates in the subject blasting agent at about 2.7 km/sec when it is heavily primed but explosion propagates in it at only about 0.43 km/sec when it is lightly primed. When propagating at 0.43 km/sec, it produces a borehole pressure that is slightly less than 1 kb, but no yellow fumes or other sign of incomplete reaction. It is a pumped AN/emulsion blend to which additional water is added by circumferential injection at the inlet of the hose through which it is pumped.

Jan 1, 1994

By Ron Fish, Cherokee Stone

Drilling and blasting in open pits is very unique in Southern Florida. Crushed limestone, the state's most abundant mineral resource, is retrieved from the bottoms of huge open pits that are completely inundated with fresh water. It is this industry that makes southern Florida the fastest growing area in the United States.

Jan 1, 1986

By Rahim G. Haghighi, Calvin J. Konya

Fragmentation is the fundamental concern of rock blasting and it measures the effectiveness of blasting. Fragmentation is sensitive to not only the interrelationship among the design variables, but also is sensitive to local geology. Local geologic conditions have a significant impact on the success of a blasting operation.

Jan 1, 1986

By Carl R. Peterson, Robert G. Lundquist

The development of a remotely-controlled drill and blast excavation system is desirable both because it is potentially more economical than mechanical tunneling in hard rock and for safety. A serious impediment to such development is the problem of relocating and reentering previously drilled blast holes to place the explosives.

Jan 1, 1983

By Minoru Kawamura, Koichi Kurokawa, Yukio Kato, Kenji Hashimoto

It is well known that ground vibration by blasting is mainly related to a distance and charge weight. However, it is not known the correlation between ground vibration and performances of explosives; for example, shock wave energy, bubble energy, detonation velocity and ballistic mortar value etc..

Jan 1, 1991

By Tom Hanke, Joe Strobbe

The 80 year old Theodore Roosevelt Dam built in a scenic canyon near Globe, Arizona is currently undergoing a major renovation. The old stone dam, built by hundreds of skilled stonemasons, is being covered with a new concrete face that will increase the dam height by 77 feet. The renovated dam will improve flood control and provide increased electrical power and recreation area. The contractor, J.A. Jones is constructing the new dam and powerhouse for the Bureau of Reclamation.

Jan 1, 1993

By James E. Jr Hargroves

With the ever-increasing population growth and modern trend to urban development, the expansion of utilities is a stable, mad or, and constant source of income for many. Blasting is a "necessary evil" to the utility contractor. It can make or break even the most solvent. Housing development expansion and higher treatment of effluents are causing utilities to appear in more congested areas. This paper discusses some of the aspects of utility blasting in the State of Virginia. Consideration is given to bid procedures, pre-blast surveys, record-keeping and practical application.

Jan 1, 1977

In this work, is being described the developing of the study for the demolition by controlled blasting project of a building of reinforced concrete, in the center of a spanish city. Synthetically, it is being analyzed the timing of the fall of the parts of the structure. This documentation is completed with a group of four photographs of the falling sequence and a film about several demolitions and the particular one described in this paper.

Jan 1, 1977

By Ivan Kovac, Pero Marjanovic, Branko Bozic

"The paper deals with results of geophysical survey of the rock masses, and the blasting parameterswhich have effect on the fragmentation in quarries . A relationship between the burden, which is the distance between the charged borehole and the free rock surface, and the velocity of longitudinal waves in the rock mass is established based on measured values for different quarries. It is shown that the drilling geometry can also be detemrined from this relationship."

Jan 1, 1999

By George P. Schivley

The careful positioning of the drill rigs that drill the holes into which explosives are then loaded is critical to the success of the subsequent blast. Today a system of satellites in space, each transmitting radio signals, is being used to provide the data to allow for tracking and positioning of various types of ground-based mobile equipment. The system is the Global Positioning System or GPS for short. This paper focuses on the application of GPS to surface mining and in particular the navigating of rotary drills from hole-to-hole and their final precise positioning to drill each blast hole.

Jan 1, 1996

By Karl E. Burgher

Accidental explosions occur throughout the world. They can happen at chemical plants, fireworks plants, grain depots, or as a result of collisions involving volatile or hazardous chemicals. It is interesting, as we know as blasters, that we can take two very harmless products and mix them under certain conditions and produce a violent explosion. It is often very difficult for the investigator to determine the magnitudes of blasts after the fact. However, an estimate must be made to settle vibration and airblast damage claims. The blasting consultant or technical representative is often called upon to act as an expert to mitigate these claims.

Jan 1, 1993

By Bob de Raadt

The main problem in blasting a fly-over spanning a main road is the brief time available for blasting and the removal of the debris, in order to minimize the ensuing traffic disruption in the public highway below. The blasting plan is consequently based on an extreme "time is money" concept, in which speed and public safety are predominant factors. This paper discusses reliable blasting parameters for this type of demolition.

Jan 1, 1984

By Lyall Workman, Jack Eloranta

In this paper results of drill to mill research are examined. It is found that several descriptors of blasting results change when the powder factor is increased. Fragmentation shifts toward a finer distribution. The Bond work index decreases and the product of the t10 model breakage parameters increases. Both of these indicate more softening of fragments. There is research that found large differences in bond work index and other studies that find a much smaller decrease. Even at the lower decrease, however, some savings in energy cost can accrue in hard ores ground to small size.

Jan 1, 2009

By Robert B. Hopler

This paper reviews, from the historical standpoint, the development of the commonly-used terms such as "No. 6 and No. 8" with regard to detonator strengths. The origin of the strength terminology is reviewed, and the many methods developed to compare the strength of one detonator to another are described, with the good and bad points of each method outlined. The "miniature cartridge test," very highly regarded by both the U.S. Bureau of Mines and Institute of Makers of Explosives in the 1930's and early 1940's, is described in detail, as is a test developed and used by IRECO.

Jan 1, 1992

By T. N. Singh, Vasudev Singh

Most of the surface mines in India have drilling and blasting practice as excavation method. All the mines have to keep the blast vibration level below a certain limit. But when mining operation is near some important civil structure, prediction and control of ground vibration becomes critical. Prediction of safe charge and finding the appropriate methodology is important for blasting near important civil structures.

Jan 1, 2006

By James D. Cook, Dan McCutchen

Effective overburden casting requires the efficient use of todays explosives and initiations systems if a mine is to survive. This paper uses a major coal stripping operation as an example of the proper application of explosives and initiation system to their conditions.

Jan 1, 1994

By Stuart Pether, Cedric Goode

The Mt Morgans Minesite is located 800km North East of Perth, the Capital City of Western Australia. The surrounding region has been a significant producer of gold since the turn of the century. The mine was previously host to a township of approx 40 - 50,000 people.

Jan 1, 1996

By Graeme Exelby

The 4" Wassara water hammer was originally developed by G-Drill AB together with Swedish Mining Company LKAB for their underground long hole production drilling. Sandvik Rock Tools AB is responsible for the introduction of Wassara worldwide.

Jan 1, 1998

By Mark S. Stagg, Rolfe E. Otterness, Farrokh Djahanguiri

The U.S. Bureau of Mines (USBM) evaluated empirical equations that predict fragmentation from underground stope rounds. Controlled blasting is necessary for creating leaching stopes that maximize the recovery and minimize backbreak of the perimeter wall. This paper presents the fragmentation results from one of the three drop-raise blasts used to develop a reduced-scale cylindrical stope, 1.8 m in diameter and 6 m in height. The stope is located in the Colorado School of Mines Experimental Mine (Edgar Mine) in Idaho Springs, Colorado. This stope is part of a USBM research effort to determine the feasibility of incorporating in situ leaching of rubblized stopes into active underground metal and nonmetal mines.

Jan 1, 1994