Search Documents

By G K. Jorkenson

The SABREX Blast Modelling Program was developed joinlly by the companies of the ICI Explosives Group. of which C-I-L Inc. is a member. SABREX (Scientific Approach to Breaking Rock with Explosives) is a modular computer program which incorporates new technology with a number of tested programs that have been in use world wide.

Jan 1, 1989

By Ann Barron

Commercial drivers have new guidelines regarding how long they can stay on the road without taking a break. Transportation officials say the new Hours of Service rule that took effect January 4th will reduce driver fatigue and prevent hundreds of injuroes, thousands of crashes and save the American economy about 628 million dollars a year.

Jan 1, 2004

By Jack Eloranta

Building on previous work, this paper expands the template for modeling the economic relationship between blasting and grinding. The actual efficacy of various blasting enhancements is not addressed, however, placing costs and potential benefits in proper context should aid in designing mine/mill optimization trials.

Jan 1, 2014

By Fumihiko Sumiya, Shinya Tanaka, Yukio Kato, Kenji Tanaka, Tetsuya Sawada

When explosives are heated under an acidic environment due to metal sulfide and sulfuric acidity, their decomposition temperature falls remarkably and decomposition reaction occurs quickly, and then explosives have the risk of the deflagration to the detonation transition. Heat resistant commercial explosives which can be used under conditions of high temperature of 200ºC and an acidic environment were studied. We developed the explosive composition consisted of ammonium perchlorate (AP) as oxidizer, saturated hydrocarbon oil as fuel and binder, and calcium carbonate as decomposition inhibitor. The characteristics of this explosive composition show a heat resistance over 24 hours at 200ºC, and a detonation velocity over 2,500 m s-1. This explosive composition has a cap-sensitivity at temperature higher than 100ºC. Cost effective heat resistant commercial explosives were created by the optimization of the grain size of AP as a main component, the addition of saturated hydrocarbon oil and calcium carbonate, and the control of bulk density by the addition of micro-balloons.

Jan 1, 2003

By Pharis E. Williams

The ability to predict the performance of an explosive relies upon having a Reaction Rate Law and knowing its functional dependence upon various parameters of the explosive. In particular, emulsion explosives have a matrix cell size and may be sensitized with glass or plastic microballoons. The cell size dependence should. be very nearly the spherical grain burning dependence upon web that appears in the reaction rate laws for ball gun powder. The dependence of the reaction rate law upon the parameters of the sensitizing microballoons has been explored using hydrocode analysis of the pressure field produced by the collapse of a microballoon. This pressure field provides an increase in pressure in the vicinity of the microballoon which, in turn, increases the rate of reaction within this field and provides the energy release that must be achieved in order to have a steady state detonation for use as a blasting agent. Hydrocode analysis allows the determination of an approximate functional form for the reaction rate law which shows the dependence upon the size, type, and quantity of microballoons. This presentation includes the theoretical background and the determined functional form of the reaction rate law.

Jan 1, 1995

Blast vibration analysis under relatively near-field conditions has been carried out in a narrow-vein underground operation. The objective was to characterize the vibration signal (particle acceleration and velocity) from carefully controlled stope blasts. The limitations of such analysis in deriving design guidelines for reducing dilution has been elucidated. It has been shown that identification of each individual hole with specific explosive types can yield explosive-specific predictive equations for particle velocity. This has been coupled with measurement of actual overbreak to arrive at a limiting vibration level to generate a realistic design tool for controlling dilution in narrow-vein mines.

Jan 1, 2003

By Peter Moser, Frank Chiapetta, Sacha Diaj, Florian Bauer

Good toe breakage and a flat working bench after blasting are important parameters to achieve a high productivity during material loading and reduce the necessity for secondary blasting. Good toe breakage requires a proper burden – side spacing design and a suitable sub-drilling. With unfavourable jointed rock mass conditions the use of horizontal bottom holes still can be found as common work practice even that this is associated to high risks.

Jan 1, 2009

By Bill Williamson, Doug Richmond, Kerri Kuntz, Gus Gilman, Larry Heywood

This was a description by the poet of what occurred over two centuries earlier to Hannibal’s troops as he passed through the Alps. Interestingly, the pass that many feel is the route that Hannibal chose, Col de la Traversette, is the sight of possibly the earliest avalanche mitigation known. Monastery records describe a tunnel built in 1470, near the top of the pass designed to protect pilgrims from the upper slopes. For the next several centuries, avoidance and reinforced structures were the primary tactics to defend from avalanches

Jan 1, 2009

By Bobby Dupree

I remember a big problem with a seismograph in the winter two years ago. In response to a citizen’s complaint I placed a transducer near the corner of a two-story home. It was a pretty nice day for the winter months, the people were pleasant, and I had no problems digging a hole to place the transducer.

Jan 1, 2004

By Robert Hopler

The use of electrical fuzes is rapidly superseding the old cap and fuse method of firing blasts. It is therefore desirable that the details of this kind of blasting should be more generally understood

Jan 1, 2006

By R J. Johnson

The development of "SANFO" has provided the Mining Industry with a LOW COST HIGH GAS VOLUME, VARIABLE DENSITY, Blasting Agent which can be blended "On Site" in a simple Agitator mixing and charging system by mine site employees.

Jan 1, 1996

By Ivan Carrasco, Benjamin Cebrian

Mining companies have traditionally organized their structure around a scheme easy to manage: Mining Department and Mill Department. In a challenging landscape for mining, with decreasing grades, increasing rock hardness and more expensive energy, this way to organize departments has resulted in internal disputes and often contradictory targets between both mine and mill. These compete for individual, separated budgets whose Key Performance Indexes often damage each other’s output. The results are increased total production costs and reduction of profits. Some companies have completed the first step in eliminating these inefficiencies by creating Fragmentation Engineers and Fragmentation Superintendents. With all the knowledge available on the overall fragmentation process and costs, in this document an overhaul of the traditional management structure is proposed. Is a step further Mine-to-mill and mine-to-leach programs. Since comminution is the most expensive step of the mineral exploitation, it should be taken as a whole, not divided into competing departments. Thus, mining departments should be re-grouped into: transportation, fragmentation and flotation.

Jan 1, 2014

By X Meng, W. A. Hustrulid, M. K. McCarter

Rock excavation in both surface and underground mining is largely accomplished using the drill and blast technique. At the perimeter of such excavations, cautious blasting procedures are often employed to minimize unwanted damage to the remaining rock. Of the several different techniques available, the use of explosive charges with a diameter smaller than the holes in which they are introduced (so-called decoupled charges) is the most common. In spite of the long and widespread use of the technique, a technically sound basis for relating the borehole wall pressure to the explosion pressure is still lacking. Such a relationship is required for optimal design

Jan 1, 2005

By Bruce Vandenberg, R F. Chiappetta

"The High Speed 2D Analysis program allows the user to bring in data from several different sources. Of course, keyboard entry is included as a source. Other data is inputted through the serial port (X-2321 of the PC. Two types of data are transferred via the serial port. The first is the tablet digitizer data. The three types supported presently are the GTCO, tablet digitizers. and the Calcomp 2500 and 9100 series To transfer digitized data turn on the selected digitizer and place the cursor on the tablet. Enter the High Speed pmg.ram and select from the Input Program menu the Digitize Inputs(20) option and follow the instructions. TO exit the session, either a keyboard entry or a cursor button is pressed. The second type of serial port input Is from the collectors of the listed survey systems. Typically a file transfer program will be used to send the data from the collector to the PC. This topic will not be addressed at this time."

Jan 1, 1989

By A. K. Mishra

The mineral industry is leading towards a technology driven optimization process. Drilling and blasting are such unit operations in a mine, which can alter the balance sheet of the mine if not planned properly. The development, improvement and utilisation of innovative technologies in terms of blast monitoring instruments and explosives technology are important for cost effectiveness and safety of mineral industries. The ever-growing demand of mineral has compelled the industry to adopt mega opencast projects with big equipments. This has necessitated use of few hundred tonnes of explosives in each blast. The bulk delivered fourth generation explosives has solved the problem of explosive loading to a large extent. The priming of bulk delivered explosives in Indian mines uses the conventional PETN/TNT based cast boosters. As the conventional cast booster possess safety problems in terms of handling and use, so Indian Explosives Ltd., has developed an emulsion based cast booster (Powergel Boost).

Jan 1, 2005

By R. Singh, M. Roy, D. Singh

Success of a blasting pattern in Blasting-off-the-solid (BOS) in Bord (Room) & Pillar method of coal mining is judged by the percentage of pull achieved vis-à-vis the yield of coal produced in a blasted round. Improper blast design and distribution of explosives in shot holes normally causes poor breakage i.e. a major portion of shot holes left unbroken resulting into reduced yield per blast. Over and above the disturbance to the roof is also due to excessive vibration caused by explosive energy not properly utilized in fragmentation.

Jan 1, 2003

By Mark Svinkin

The purpose of this paper is to present an overview of recommended existing criteria of ground vibrations generated by blasting. It is shown that these criteria have limited liability because they were found for specific categories of structures. A new approach based on measurement of structure vibrations is suggested for assessment of damage in structures subjected to blasting vibrations. This approach provides the flexibility of implicitly considering a variety of soil-structure interaction and structure conditions. It is explained a new frequency-independent safe-level criterion of 51 mm/s (2 in/s) for the PPV of structural vibrations. Attention is brought to use seismographs properly calibrated for the required frequency range. Positive flexibility is demonstrated in assessment of structure and component of concern vibrations from blasting.

Jan 1, 2003

By Doug Bartley, Roy McKinstry, John Floyd

In March of 2001, Barrick Goldstrike became the first surface gold operation in North America to evaluate the advantages of electronic detonators. A detailed study was conducted to quantify the benefits of the use of electronic detonators to the downstream excavation, crushing and ore processing operations. The following methods were used to quantify blast performance:

Jan 1, 2003

By D T. Froedge

With successive generations of the Iso-Seismic System, we are acquiring more and more information about the actual behavior of blast induced ground, and airborne vibration, as it propagates through the environment. Some of the original “truths” that have been long accepted may have to be \revised.

Jan 1, 1995

By John Brown

Let’s talk about things that you, the driIl boss, the pit boss and the driller can do to eliminate the trend in drilling related accidents that have come to plague our industry in recent years. My paper will focus on reaI issues, problems and solutions that will affect our everyday outlook and attitudes about our jobs and lives. There are some real hard facts we must address if we are going to reverse this terrible killing trend.

Jan 1, 2000