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By Lina Lopez, Jose Sanchidrian, Manuel Lopez, Pablo Segarra

Previous work in which rock properties and blasting parameters (geometry, charging and timing) were reported together with truck filling times, is taken as a starting point for a thorough analysis of the influence of the former on the mucking velocity. The experimental set was composed by 11 blasts made in an open pit mine. Non-parametric, distribution-free statistics is applied. The mucking rates (in bank cubic meters per unit of bucket volume and per hour) appear to be clearly dependent on the explosive energy and powder factor, both magnitudes combined as energetic powder factor (energy per unit of rock volume). The mucking rate is a non-monotonic function of such factor in the range of the blasts analyzed. The determination of the function is optimum when the fraction of the explosive below grade is not considered and when the explosive energy is qualified as that delivered at a partial detonation regime. Different types of loaders seem appropriate for different energy levels. At low levels both front loaders and rope shovels obtain small productivities without a statistically significant difference in their performance. At high energy levels, front loaders qualify higher than rope shovels. Mucking velocities can be equally small at low energy powder factors and at high ones if rope shovels are involved.

Jan 1, 2008

By Inc. The HDH Group

The Alternative Risk Market is defined as the segment of the insurance market that is made up of self insurance, risk purchasing groups, risk retention groups and captives. It is commonly referred to as the alternative to the traditional market, even though more the majority of companies today are insured through the alternative risk market than the traditional market.

Jan 1, 2007

By Jin Jingzhi, Wang Xuguang, Guan Li, Li Jianjin

Emulsion explosives are gaining a wider and wider commercial market and are displacing other composite slurry technologies. However, the grease-like state and essential thermodynamic instability of emulsion explosives cause inconvenience in production, transportation, storage and use and lead to gradual changes in performance. Emulsion powder explosives are designed to avoid these disadvantages. The formulation, process and properties of emulsion powder explosives made through a spin flash technology are described in this paper.

Jan 1, 1997

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 Lewis L. Oriard

Both theory and experience tell us that spatially distributed energy sources generate a more complex family of seismic waves than do point sources. The resulting effects in the near field (for close-in blasting) are significantly different than those from point sources although, at great distances from the source, the seismic waves take on many of the characteristics of point sources and can often be treated as such.

Jan 1, 1992

By John J. Barnes

The advent of more powerful explosives, increased bench heights, and larger diameter blastholes has necessitated the use of presplitting techniques in sub-bituminous coal mines. The combination of these factors has increased the energy concentration during blasting, producing severe overbreak problems in the final pit walls. Presplitting with large diameter blastholes has proven to be the most viable method of reducing back break in sub-bituminous coal mines.

Jan 1, 1988

By Fred C. Drury

The introduction and growth of modern chemical explosives based upon prilled ammonium nitrate has been the most significant development in the explosives industry during the 20th century. These modern chemical explosives have been of incalculable value to our society. Their use has permitted a reduction of blasting costs, improved safety, and the development of new resource sources which would not have been accessible without this new technology.

Jan 1, 1980

By J S. Kuszmaul

The economic development of modified in situ oil shale retorting will benefit from the ability to design a blasting scheme that creates a rubble bed of uniform permeability. Preparing such a design depends upon successfully predicting how a given explosive will break rock. Numerical models are used to make predictions of the extent of damage caused by an explosion.

Jan 1, 1985

By M Oldenburg, P J. Digby, L Nilsson

A constitutive model for the simulation of fracture and fragmentation processes in rapidly loaded rocks is studied. The model was included in a wave propagation finite element code. The results obtained from two different configurations of explosive charge and reflecting surfaces in a plane strain problem were studied. The evolution of the time-dependent fracture pattern is presented.

Jan 1, 1985

By Mark S. Stagg, Stephen A. Rholl

The Bureau of Mines is studying blast delay timing influences on rock fragmentation in a series of tests that started in 3-ft concrete blocks, progressed to 45in-bench reduced-scale tests in massive dolomite, and has now included 22-ft-bench full-scale tests in a thin-to-thick horizontally bedded dolomite. This paper discusses the full-scale test results and how they compared to the concrete block and reduced-scale studies.

Jan 1, 1988

By Gerald R. Coonan

Laboratory research is being conducted to substantiate suggested levels for voluntary standards on human response to transient vibration. The application of those findings to actual field conditions, however, will be limited because they will not include social and psychological factors existent in the real world. It is necessary, therefore, to examine available empirical information on complaints in an attempt to define the influence social and psychological factors might have on the laboratory results.

Jan 1, 1982

By Detlef Sulzer, Winfried Rosenstock

"At the end of this century a great breakthrough in the field of blasting technology is finally going tobecome reality. That, in the true sense of the word, is the long expected and desired “HighTechnology Blasting”. So far trials have been carried out in Australia, Africa and Europe with remarkable results, that have been predicted by the authors. As a result, significant reductions of explosives and drilling expenditure are emerging for the future."

Jan 1, 1999

By Stephen H. Chung

Direct visualization of rock movement during blasting is an important key to understanding the blasting process, as well as optimizing blast designs and explosives performance. To achieve this, a digital camera system (HSIS-500) has been built. It is a custom made high speed solid-state camera employing an advanced charge coupled device (CCD) and dynamic random access memory (DRAM) technologies. It handles like a regular video camera but requires no film or tape as the image is recorded in digital form on memory chips and transferred to the system hard disk for storage. The system consists of two components: the camera body and hardware, and the image processing unit.

Jan 1, 1996

By Michael McDougall

"Suncor Inc. Oilsands Group, Mining Operation in Northern Alberta, Canada, has beenblasting to loosen the oilsands to increase production and decrease maintenance of the hugebucketwheel excavators for over twenty years. In 1991 an area of the mine wasencountered which had a working face in excess of 130 feet. In order to maintain theproduction objective, the blasting department took on the task of providing as much of ablasted face to work with as possible. In doing this Suncor has exceeded several knownrecords in production blasting."

Jan 1, 1993

By W C. Burkle

A rather common observation over the last several decades at least has been that rock or ore properties influence blasting results more than does the explosive type that has been used in the blast. It we accept that premise than it is held here that the material to be blasted should receive even closer attention as to its properties. Several years ago, Dr. Richard Ash published papers that pointed out the rock properties that mostly influence blasting. These principles are given attention in this paper. We have gone somewhat further - or lets say expanded this subject in regard to the role of rock structure in open pit blasting. Though open pit work is given some prominence, we believe that much can be observed and applied to underground mining.

Jan 1, 1979

By Goran Cirkovic, Zvonimir Ester, Josip Krsnik

During the reconstruction of the motorway Zagreb-Krapina three reinforced concrete bridges were demolished, for their width was not adequate for the new motorway. Demolition of the three bridges was carried out by blasting as duration of the traffic cut on the motorway and the railway was limited to maximally 4 hours. During that period of time the demolished bridges had to be removed. Therefore, very tiny granulation was requested suitable for loading and not endangering the surrounding structures. Before each of three main blasting, trial blasting were carried out including the seismic measurements registering the seismic effects. The nearest residential building was at the distance of less than 30 m from the place of blasting. Additional difficulty was the fact that by each of the three bridges there is a new bridge, with minimal distance between the old and the new bridge being 30 cm. As each of the bridges is of different construction and of various thickness, particular blasting technique has been prepared for each one of the bridges.

Jan 1, 1997

Almost one half of Canada's total land surface is underlain by permafrost. This term describes the thermal condition of earth materials when their temperature remains below 0°C continuously for a number of years. The drilling and blasting of frozen materials requires more energy than the blasting of same in its unfrozen state. The cost of comminution could double in permafrost even with adequate organization, drilling equipment and proper explosives.

Jan 1, 1975

By M. L. Mendes, J. Q. Nojiri, S. C. Botelho, A. P. Campanha

In February 28, 2001 JOULE coordinated the first tests with an electronic detonator in South America at an iron ore operation - ITABIRA MINES from the Brazilian COMPANHIA VALE DO RIO DOCE (CVRD) - the largest producer and exporter of iron ore in the world. ITABIRA MINES (CAU and CONCEI O) belong to one of the complexes, called the Southern System, producing 56 million tons of ROM as well as concentrated products and pellets. This paper is going to describe the tests at ITABIRA MINES with results indicating the improvement in the excavator productivity and reduction of the mining global costs (due to the better performance of the equipment and potential reduction of the maintenance cost).

Jan 1, 2002

By Ken Tunnel

In the spring of 2005, the Lake Superior Chapter of the ISEE invited me to speak about raw materials used for blasting, anhydrous ammonia and the effect of this important feedstock on the cost of ammonium nitrate.The invitation was extended because our company is involved in trading ammonia and the production of ammonium nitrate. In a response to a request to update that presentation, it struck me how events such as hurricanes Katrina and Rita can change the landscape of our businesses.

Jan 1, 2007

By Heins Walter Wild

Detailed investigations on various configuration kinds of cut with respect to drilling-technological and blasting-technological properties as well as with respect to cost effectiveness have been carried out in Germany.

Jan 1, 1995