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By Pierre L. Labelle

Non electric Dual Delay initiators have revolutionized many aspects of underground mining. The units are used in all types of underground blasting operations. Some operations, due to the complexity and variety of their blasts, have extremely large inventories of conventional non electric products. The Dual Delay system has drastically reduced these inventories and has added an important element of versatility to blast designs.

Jan 1, 1994

By Kunihisa Katsuyama, Yuji Ogata, Yuji Wada

The one free surface blasting of a concrete block was simulated by Discontinuous Deformation Analysis(DDA) method. Comparing the simulated results with the concrete block blasting experiment, the crack growth and the free surface displacement which were simulated by DDA were observed with a high speed camera.

Jan 1, 1996

By Michael S. Wieland

This report focuses on the U.S. Bureau of Mines research regarding desensitization and malfunction of delay detonators and cap-sensitive explosives. Delay blasting in underground coal generates tremendous shock waves and rifting forces that fracture and heave coal. The shock waves from charge explosions radiate outward in all directions through the coal, impacting neighboring charges with later delays. The impact phenomena have debilitating effects, causing degrees of reduced charge performance ranging from misfires or weak detonations to out-of-sequence detonations. Impaired charges react poorly, fracture less coal, and produce fumes with higher toxicity. Coal-mine, underwater, and simulator tests were conducted to more thoroughly understand the shock damage mechanism. Recently the U.S. Bureau of Mines partially resolved the malfunction problem by demonstrating the feasibility of formulating a rugged explosive. This rugged cap-sensitive candidate passed the requisite tests for certifying an underground coal-mine explosive. With natural aging the formulation rapidly lost initiation sensitivity. The charge formulation had to be rebatched to finish the testing and therefore could not be certified.

Jan 1, 1992

By Lars Arne Granlund

Due to the coarse structure of mining explosives, one has to model a finite reaction zone,contrary to C-J calculations, describing their detonations, i.e they become dependent of diameter and confinement, An effort within the DYNO group has been to investigate if the DSD theory ( originally developed by Bdzil, Stewart / Los Alamos ) can be used to describe major groups of civil explosives.The groups of explosives tested are dynamite, anfo, aluminised emulsion, heavy anfo and straight emulsions.

Jan 1, 1995

By William Hustrulid

Pre-split blasting is a primary technique for creating slopes with a minimum amount of unwanted damage to the remaining rock mass. Rock slopes created in such a way have both safety-related and economic advantages. The applications extend from road cuts to rock quarries to large open pit mines. For example, as deep open pit mines approach the end of their operating lives, slope steepening is one option to be considered. To be able to safely achieve and maintain steepened final slopes, good blast design techniques must be available and applied together with close operational control. Pre-split blasting is an important element in this slope creation process.

Jan 1, 2007

By Serge V. Krasavin

The behavior of rocks subjected to dynamic loading conditions under explosion includes sufficient information about hydrodynamic variables such as pressure P, mass velocity U, internal energy E, specific volume V and density p as functions of time. Measurement of dynamic characteristics in compressed media with manganin wire sensors has become common in the past few years, but the experimental data for certain media, such as rock, do not provide an exhaustive description of rock's behavior in the near zone of an explosion, which is highly responsible for the transformation of energy of explosives.

Jan 1, 1992

By Taner Sumer, H Altay Guvenir

Fragmentation in rock quarries is tried to be achieved by changing the specific charge, drill pattern and bore hole diameters by different experts. This paper is a brief summary consisting of the utilization of practical experiences of the other group on cost optimization procedure that takes into account blasting, transportation and crushing as a whole process and optimize the cost by defining the optimum gelatin based explosives to be used as a main primer of anfo in three different limestone and granite quarries, with similar rock characteristics.

Jan 1, 1993

By K B. Holm

This paper deals with the advances made at Syferfontein Colliery in the calculation and control of dragline methodology. The high capital outlay and operating cost of a dragline necessitates strict control of all aspects of the dragline operation. Before purchasing a dragline, a complete evaluation of all the parameters that can affect the viability, now and in the future, of the dragline operation needs to be completed. Such parameters as thickness of burden, material properties (swell), “castability”, pit width and pit length, etc. need to be considered.

Jan 1, 1994

By Gregg A. Scott, Gordon F. Revey

"The Folsom Dam is a 340-foot-high concrete gravity dam with embankment wing dams located on the American River about 20 miles northeast of Sacramento, California. Folsom Dam is operated andmaintained by the U. S. Bureau of Reclamation (Reclamation). As part of the Central Valley Project,Folsom Dam is a multipurpose facility providing water supply storage, flood control, power generation, and recreational opportunities."

Jan 1, 1999

By M. Hagfors

Underwater explosions have been used several decades for the determination energy content of explosives. It’s the only test method by which shock and gas heave energy values can be determined separately. The total energy is a sum of these two partial energies. This test method enables us to develop explosives for different purposes; the military high explosives should contain more shock energy whereas the gas heave energy is a very important feature for the blasting explosives. The method also enables us to observe the changes and to adjust the energy content of an explosive as a function of increments of one or more energetic component.

Jan 1, 2006

By P J. Hommert, D S. Preece

"Commercial development of the United States Oil Shale reserve will require substantial amounts of mining. In fact, even a modest 500,000 barrels per day industry requires a mining effort equivalent to nearly half of the current U.S. coal mining industry. Obviously, mining efforts on this scale will benefit from technological advances. There are a number of areas where advanced technology could impact mining. These include continuous miners, shale transport systems, and blasting. This paperexamines recent developments in computer modeling of blasting and assesses the likelihood of these advances being applied to practical oil shale mining problems."

Jan 1, 1989

By R. F. Favreau, P. Favreau

Rock excavation is the first process in the cycle of operation of a mine, and efficient blasting is paramount to the profitability of the mine. The traditional way to design blasts has been by trial and error, based on the experience of the designer. This is probably the only important engineering practice which continues to be done without a precise engineering technique. The efficiency of most other mine processes has been improved by the use of high-tech, while a majority of blast design has not yet profited from the advantages of the computer. However, with the advent of the high-tech blast simulator Blaspa, it has become possible to design the parameters of the blast according to normal engineering practices. Over the last 50 years, the chemical and physical mechanisms which occur during a blast have come to be identified; they are reviewed in section B. Although these mechanisms are complex, they have nevertheless been expressed in terms of mathematical equations which have been assembled together in the computer to create the blast model Blaspa.

Jan 1, 2002

By Brian W. Stump

"Seismic waves from explosions can be used to characterize physical processes in and around the source. The quantification of absolute levels of ground motion is important for minimizing impact on nearby people and structures. We contrast work in characterizing seismic radiation from contained nuclear explosions with ground motions from multiple explosion quarry blasts. A physical basedunderstanding of the explosion source function allows prediction and extrapolation to new environments where experimental data may not exist."

Jan 1, 1990

By Attie J. Goosen, William L. Spiteri

Although the physical characteristics of ANFO made from porous prilled ammonium nitrate (PPAN) have been altered by the addition of crystal modifiers, the optimisation of prilling processes and the admixture of waterproofing agents, the sensitivity of this explosive has not been modified on a commercial scale in the 40 years since its accidental discovery.

Jan 1, 1995

By Mark William Withey

"Blasting safety in surface mining is a necessary industrial goal. Proper techniques and disciplinesexercised during the blasting process enhance the probability of achieving that goal.The blasting process is generally a series of repetitive steps performed by all blasting technicians.Because habits formed during this process influence safety, production and cost, proper habitsbecome compulsory."

Jan 1, 1995

By Lex L. Udy

Properties of an explosive which itiuence its performance on rock breakage are analyzed in relation to the rock: hardness and a discussion on the interaction of an explosive with the rock during the blasting process is given. Theoretical concepts regarding ideal and non-ideal detonation are reviewed to explain how the physical and chemical factors of an explosive influence the rate of energy release and its consequence on blasting performance. While a lower velocity of detonation indicates a slowed chemical reaction it does not necessarily mean a loss in energy from the explosive. High density ammonium nitrate (HDAN) can be used effectively in the formulation of modern industrial explosives to slow the energy release rate with its attendant decrease in detonation velocity. Examples of blasting performance using custom formulated explosives with HDAN are presented.

Jan 1, 1995

By John Haviland, Richard E. Danell

"BHP Australia Coat Pty Ltd (BHPAC) operates seven large open pit coal mines in the Bowen Basin ofCentral Queensland, Australia. These mines have operated for periods ranging from 16 to 37 years. All of these mines have dipping seams to varying degrees and are facing increasing overburden removal in an effort to maintain production. To ensure the economic viability of the operations, this increased level of overburden removal must ah.0 be conducted at lower unit costs."

Jan 1, 1995

By Leon Lorenzen, Victor E. Ross, Anton W. Kleingeld

"Key to successful innovation, whether at organization, industry or national level, is the alignment and utilization of resources in the most appropriate and efficient way. Innovation needs to be directed strategically, and it needs to be auditable in a systematic and integrated fashion. In the light of these considerations, this paper describes the construction and use of a topographical map of the innovation landscape of an organization. The purpose of the map is to provide a holistic view of the key factors that enable innovation (the so-called 'landmarks'), how well they are aligned to support a particular type/nature of innovation in the organization (e.g. radical vs. incremental innovation), and to identify possible gaps between actual and sought performance.The landscape covers four domains that influence innovation - the attributes of the individual, the organizational context in which he/she functions, the business environment (the market / industry in which the organization is operating) and the external environment. The significance (importance) and height (performance) of the landmarks in supporting and enabling innovation within the organization is determined by means of a self-appraisal audit. The topography of the landscape derived thus is subsequently interpreted in terms of the organization's particular innovation strategy and environmental context."

Jan 1, 2003

By Jack Eloranta

"This paper compares energy requirements for blasting, crushing and grinding. By tracking electricalconsumption for various powder factors, a general trend has appeared. This study involved over 100million tons of ore and powder factors ranging from .5 lbs/L,T to .8 lb&T. Actual energy usage iscompared to predicted energy based on the Bond equation."

Jan 1, 1998

By Young-Dong Cho, Yonghun Jong, Dong-See Shim, Seokwon Jeon, Chung-In Lee

The most important operation in the tunnel blasting procedure is to create an opening in the face in order to develop more free surface in the rock mass. This operation is highly dependent on the cut holes. In general, the burn-cut or V-cut is commonly adopted to blast the cut section. But, these traditional methods often raise problems. There are instances (a) that the actual advance is considerably less than the designed advance depending on the rock mass, (b) that they cannot sometimes enlarge the free surface efficiently and (c) that the blast vibration resulted from the cut blast exceeds the allowable vibration level. In order to resolve the problems, many different kinds of the cut blast can be considered.

Jan 1, 2005