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By Sandra Penttinen

To assist blasting professionals with the creation, documentation, and appropriate methodology to standardize the data collection of the pre and post blast investigation process. Penttinen Associates will present a logical non-technical presentation focusing on: Why pre-blast surveys SAVE How to prepare for pre-blast inspections What to do in preparation of pre-blast inspections The creation of an industry standard all-inclusive pre-blast document Establishing pre-blast inspection operational standards Preserving the data.

Jan 1, 2001

By Zach Ellis, Dusty Fisher

The Office of Surface Mining, Reclamation, and Enforcement (OSM) cited a large surface coal mine for a series of flyrock incidents that occurred when blasting close to the mining lease perimeter. The OSM placed the company on a pattern of violation status. It was determined through analysis of blasting practices that flyrock could be controlled at the mine by drilling a smaller diameter hole and stemming with crushed rock when blasting within 1,000’ (304 m) of the lease line. The procedure to install and remove the small diameter drill steel was cumbersome and dangerous because it was a manual transition. The drill carousel could only hold one diameter at the time the project was initiated. The process was very time consuming, involving a mechanic to transport the steel to the drill and spend up to 1.5 hours of downtime switching the steel. In addition, the hydraulically operated break-out wrench and break-out fork on the SKS Infinity Redrill® is only designed to work with one diameter, so these tools could not be used to disconnect subs and steels on the string. At the time, the mine’s breakdown was between 30-40% small diameter (6 ¾” (171 mm)) versus large diameter drilling (10 5/8” (270 mm)). The drill and blast group was challenged with the task to implement a 6s (Six Sigma) project that would reduce the amount of time spent on steel change-outs on the rotary drills while improving the safety of the task. A solution was proposed to carry the small diameter drill pipe, lower small diameter sub, and small diameter bit on board the drill at all times. The goal of the project was to carry the steel in the carousel after modification so that the driller could change the diameter himself on board the drill in less than 45 minutes without any assistance from a mechanic. The drill had to be modified so that the hydraulic operated break out wrench and deck fork could be utilized on both diameters. The drill accessory supplier and the mine worked together to design and implement design changes and new equipment onto two rotary drills, and new standard operating procedures (SOPs) were created for the new process. The project has been in the sustaining phase for approximately three months now and all steel diameter changes are completed by the operator under the allowable time limit.

Jan 1, 2015

By Tristan Worsey, Nathan Rouse

The Florida legislature allocated funding for the Florida State Fire Marshal (FSFM) to review the applicability of the United States Bureau of Mines (USBM) Report of Investigations (RI) 8507 blast vibration limits with respect to Florida and its soils. The study also discusses whether the current blasting vibration limits set by statute are still appropriate, including a review of measured vibration amplitudes and frequencies, structure responses, and theoretical analyses of material strength and strains

Jan 1, 2019

By D. S. Scovira, T. Gustavsson

Exiting WW2 (mid-1940s), the potential of nitrates (ammonium nitrate, calcium nitrate, sodium nitrate) and hydrogen peroxide for application as a commercial explosives for mining, construction, and other industrial purposes both became known. The technology stream advanced the development and uptake of nitrate based explosives to the point that they are the current global standard for blasting. Today, environmental issues are shaping the strategic agenda across various industries. Most global mineral resource, construction houses, and explosive manufacturers have publicly announced ESG carbon reduction commitments in support of COP26 Net Zero 2050. The mid-2010s saw a renewed interest in hydrogen peroxide explosives to eliminate NOx fume. Carbon reduction initiatives in the early 2020s provided additional impetus to investigate hydrogen peroxide based explosives for industrial use. Hypex Bio has recently pioneered the formulation, manufacture, and end-use delivery of a Hydrogen Peroxide Emulsion (HPE) on an industrial scale. The HPE is composed primarily of hydrogen peroxide (H2O2) plus a lesser amount of fuel and emulsifier phase. The base HPE is produced in a low energy intensity modular plant using industry proven mixing techniques. The base HPE is a white, highly viscous emulsion that is similar in consistency to base nitrate emulsions. To enable end blasting use, a mobile charging unit gases the base HPE to a detonable density. The HPE is compatible with current priming and initiation systems. Hydrogen peroxide explosives offer a significant reduction in total carbon emission as compared to nitrate based explosives. The production of ammonium nitrate (AN) emulsion is energy-intensive and not carbon neutral. Based on the EU Average and for the oxidizer phase only, 1 kg [2.2 lb] of AN emulsion emits 2.3 kg [5.1 lb] of CO2 as compared to the production of hydrogen peroxide emulsion that results in 0.23 kg [0.5 lb] of CO2. This is a difference of 90%. HPE contains no nitrates and does not generate post blast nitrous oxides (NOx). HPE generates no aqueous nitrate or ammonia pollution and is a solution to meeting increasingly regulated mine site water discharge limits. Hypex Bio recently conducted a successful underground HPE evaluation with a major mining company in Sweden. HPE blast designs were the same as those done with nitrate based emulsions. Rock breakage, advance, muck displacement, and excavator performance were equivalent. Ventilation and re-entry times were reduced. The mining company has expressed further interest in assessing HPE and is demonstrating industrial leadership by exploring this transformative explosive technology

Jan 1, 2024

By W Barry Gregg

The rock blasting and mining industries use a system of detonators and explosives for mining operations. Many detonators use small metal bridgewires, which are heated by passing a current through the wire, heating and igniting the pyrotechnic powder in contact with the wire, Typical bridgewires require a current of at least 3 amps, applied for a few milliseconds, for an explosive output. The semiconductor bridge (SCB), in comparison, initiates an explosive in 0.01 to 0.1 of a millisecond.

Jan 1, 1992

By Leon del Valle, Joe Phillips

First, I want to thank my co-author, Leon del Valle for his help and collaboration in the preparation of this paper, and also ORICA S.S. our explosive supplier and contractor at the Refugio mine site for their collaboration. The Southern Andes Mountains present a number of challenges for mining operations, and associated blasting operations. This region of the world, in Peru, Bolivis, Chile and Argentina is an area of rapid growth in precious and base metal mining, and will continue to be a large growth area for explosives products and services. This paper will attemp to discuss some of the special considerations encountered in operating a safe and effective blasting program at high elevation and under extreme weather conditions, as well as outlining a recent improvement in blasting techniques at the Refugio gold mine in northern Chile. This paper is presented from a mine operator's perspective, which may be a bit of a disappointment for some of you interested in a detailed technical review of our program. It willl, however, provide an insight in how in-pit blasting techniques tie into the metallurgical processes at a modern precious metal mine and thereby become a key elemnet in its success.

Jan 1, 2000

By Steve Colburn

The CRITERION Survey Systems utilize both theodolite mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environments characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, Windows-based, interactive software program which can be run on’ any standard PC.

Jan 1, 1998

By Tom Treleaven, Andrew Williams

Several contracts were let in Greenwich, Connecticut, for the installation of a sanitary sewer. The majority of the excavation was in rock and involved numerous challenges due to the following conditions:

Jan 1, 2003

By Thomas Barkley

Recent developments in hardware and software have made accurate measurement of Underground Face (Development) Drilling a reality. New and compact laser profiling equipment makes it possible to measure drilled material left on the face as well as the actual tracks of the holes drilled in the rounds. Utilization of these available technologies makes it possible to correctly define the drilling accuracy and the blasting pull. Through the use of actual face round measurements, I will show the level of definition and amount of information that can be collected.

Jan 1, 2003

By Ola Lindahl, Mark Irving, John Hutchings

"Blasting is a process starting with a geometric description of the block of rock and ending with a pileof fragmented material. A key step in improving the productivity and quality control over the processis the integration of blast planning software, explosive delivery control systems, and blast recordingwithin one seamless customer solution."

Jan 1, 1997

By Dave Otto, Ron Elliot, Ed Hatch

This paper is a summary of the work carried out by an international team of specialists in the successful explosive compaction of the sand fill core of the Molikpaq offshore oil production structure. The sand fill core is an essential element for the stability of the structure. The sand core must resist liquefaction forces caused by heavy wave action, ice loading, and earthquakes. Explosive compaction methods were used to improve the stability of 220,000 cubic meters of coarse dredged sand placed in the core area. This project was challenging for a number of reasons. It was performed offshore in Russia, seven kilometers off the East Coast of Sakhalin Island. Logistics were a challenge, not just in getting the men and materials to the site, but also working with restricted headroom inside an operating oil drilling platform. This project called for the use of specialty explosives, strict blast vibration controls requiring a complex sequential blast design, and use of custom designed drill rigs. As Russian equivalent explosives were not available, the project involved getting approval for use of North American explosives in Russia, and use of a combined Russian - Canadian blasting crew. The blasting program was carried out successfully, meeting the required densification target _in a safe, effective manner, with no damage to the structure.

Jan 1, 2000

By A Rorke, B Cubitt, R Beeslaar

The recent drop in the value of the South African Rand has resulted in an increased export value for South African coal and has lead to new coal reserves becoming available for mining. Very often these reserves are in close proximity to existing structures and utilities thus calling for stringent blast control measures to keep the risk of vibration, air blast and fly rock damage to a minimum.

Jan 1, 1997

By David Reddick

The mining industry is in the midst of dramatic change. Mining activities are moving from industrialized first world countries (Canada, Australia, and the United States) to the third world. This shift is occurring due to depleted reserves, tough environmental standards, and expensive labor in traditional mining countries. During a recent trip to South Africa, I was asked, owing to my educational background in economics and an international involvement in drilling and blasting, what changes could be anticipated in third world blasting practices as labor costs increase. It is from that beginning that this presentation has evolved.

Jan 1, 1997

By Teele Tuuna, Voglers Eesti OÜ

Blasting operations are a strong and important part in any kind of building and mining industry, a shot-firer profession is one of the oldest professions in the civilized world. It still serves an important and ongoing purpose in the modern economy all over the world. Europe, nowadays, values strongly the mobility of workers, the movement of know-how and labor force between different countries inside Europe. There are no borders for most of the everyday professions.

Jan 1, 2018

By Michael S. Wieland

"Toxic fumes cause fatal andnonfatal incidents in underground mining, where the working environment tends to trap the fumes, hindering the restoration of non-harmful conditions. Workers can underestimate the residual fume toxicity and return to the work site too quickly. The toxic fumes from charge explosions depend upon a number things: formulation ingredients, mixture uniformity, water resistance, hole contaminates, rock hardness, and dust interactions. Transitory hole-to-hole waves can cause partial desensitization, ruin the reaction kinetics, and worsen the fume toxicity.Traditionally the toxic fume hazard for a candidate explosive is resolved from a requisite tally of fume components. The resolution starts with the fume spectrum, a tabulation of specie concentrations, transformed to standard reference conditions and readjusted to remove the air dilution. The resultant influence, which is referred to as relative fume toxicity RFT, is deduced by a formula rule with some chosen constants and the requisite concentrations. The RFT result is normally compared to an RFT criterion that represents the worst-case (maximum) tolerable fume toxicity, as stipulated by regulations or otherwise."

Jan 1, 1997

By Gary Eck, Kevin Tallent

Over the past decades, the science of energetic materials has advanced dramatically in both the fields of military munitions, as well as industrial explosives. Out of necessity, test methods to measure the explosive performance properties of these materials were developed. As would be expected, these test methods have evolved and become more sophisticated with the recent advancements in electronics and computerized technologies.

Jan 1, 1998

By W B. Gregg

The rock blasting and mining industries use a system of detonators and explosives for mining operations. Many detonators use small metal bridgewires, which are heated by passing a current through the wire, heating and igniting the pyrotechnic powder in contact with the wire. Typical bridgewires require a current of at least 3 amps, applied for a few milliseconds, for an explosive output. The semiconductor bridge (SCB), in comparison, initiates an explosive in 0.01 to 0.1 of a millisecond.

Jan 1, 1994

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 Martti Hagfors

The Finnish Defence Forces Technical Research Centre (PVTT) studied the effect of shape of boost-er to its ability to ignite insensitive (IM) plastic bonded explosive (PBX). Therefore an explosive fac-tory produced 20 insensitive (IM) plastic bonded explosive (PBX) charges for the tests. The mass of each of the charges was exactly 9.2 kg (20.3 lb). The charges were equipped by two different type of boosters; RDX and PETN. Both the explosives contained some parts of plasticizers. The weight of all the boosters was exactly 300 g (0.66lb). On the bases of their shape, the boosters were also divid-ed into two different groups, cylindrical and “pancake”. In the middle of the “pancakes” there was also shaped a small cone in such away that the detonation could accelerate to its full speed after the charge was ignited. The following shots were exploded;

Jan 1, 2013

By Peter Moser, G. Reihholf

Holcim, one of the world's leading suppliers of cement, aggregates and concrete, has set up a few years ago a working group “Quarry” in order to optimize the performance of its central European quarry operations in terms of work safety, environmental standards and economic performance. One of the activities of this working group "Quarry" addresses the subject of blast fragmentation in the quarries. A benchmark study of the blast work in all quarries has shown substantial differences for the various operations in terms of drill& blast costs. Especially big differences were found with respect to the drilling patterns as a function of the borehole diameters and with respect to the utilization of the borehole volume for charging the explosives.

Jan 1, 2006