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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 Alexandre Passos, Giorgio De Tomi, Tatiane Marin, Dennis Cremonese, Jacopo Seccatore

"In the mining industry, rock excavation is the first phase of the comminution process. Downstreamoperations such as secondary breaking, crushing and milling terminate the process, reducing the size of the grains down to the desired particle distribution. In such a cascade process, every process upstream heavily influences all the downstream operations. When rock excavation is carried out by drilling and blasting, a very economic source of energy (the explosive) is used at the utmost upstream; a more expensive source of energy (electricity) is employed for all the downstream phases. This means that managing the correct employ of the explosive energy is a form of managing the whole process, controlling the operational costs and therefore the profitability of the whole business. We simulated this cascade behavior, using as a starting point the experimental data obtained from small-scale block blasting, evaluating the influence of blasting on the grindability of the blasted material. This study showed the reduction in visible (particle size) and invisible fracturing (micro-cracking, resulting in a reduction of the Work Index WI). The particle size distribution for full-scale blasts was estimated by means of algorithm simulation, then we simulated the behavior of the comminution plant fed with the material possessing the characteristics previously estimated. All the costs (drilling, blasting, electric energy for the engines of the crushers and mill) were calculated and charted. The results show a clear curve that allows to estimate the minimum operating expenditure (OPEX) for the whole mine+plant framework. Being the WI dependent on the output on the blast, one can manage the performance and the expenditure of the whole comminution process by adjusting drilling and blasting parameters For any given mine, it is possible to perform a simulation and encounter the minimum OPEX scenario for the comminution process and managerial choices can be oriented accordingly. In a cascade productive chain as mining is, responsible strategic choices must be taken looking at the entire production framework. Compartmentalized managerial staff and budgets for separated production areas are not acceptable anymore. Somehow higher costs upstream can lead to effective decrease in costs and increase in efficiency and productivity of the processes downstream."

Jan 1, 2016

By Alex Chapman, Cam Thomas, Bryan Karney

"During the early summer of 1989, Ontario Hydro removed a concrete portion of the North Channel Dam at Crystal Falls Generating Station by blasting and excavating in marine conditions. Because of the severity of underwater blasting and because the site was in close proximity to the replacement dam, there was concern that hydraulic shock waves generated by the detonation could damage either the new dam or its control structures. This paper examines the data associated with the hydraulic shock waves generated by underwater blasting, and studies the effectiveness of an air curtain in reducing the peak pressures. In previous trials using the air curtain technique, a rule-of-thumb factor was used to estimate that only 10% of the original pressure pulse would propagate across the air curtain. However, this value had little basis in theory. A theoretical formulation of the problem by Karney in 1989 indicated a provisional value of 0.18 for this factor, but was heavily dependent on confirmation from in-field testing. Data provided by Ontario Hydro from an actual blasting procedure indicate that a more conservative value of 0.32 may be more appropriate. Thus.although the air curtain did provide considerable reduction of peak pressures, the data at Crystal Falls indicates its performance was below the anticipated level. However, due to problems with the instrumentation and some inconsistencies in the resulting data. it is recommended that this value be further refined as additional data become available."

Jan 1, 1992

By Hae-Moon Choi, Sang-Don Lee, Chang-Ha Ryu

The purpose of the study presented in this article is to establish a standard blast pattern to yield optimum blasting performance along with an attempt to reduce a difference between design and construction. A series of test blasts were carried out at two tunneling sites of Central Inland Highway crossing in Korea. Long-hole blasting was tested in rock mass whose RMR value is over 60.The blasting results were evaluated by measuring degree of fragmentation, advance rate,muckpile distribution, overbreak, etc. Based on the results of test blast, several patterns were proposed for a two-lane highway tunnel.

Jan 1, 2006

By Reinhold Schnell, Piers Wendlandt, Nathan Rouse

Drilling and blasting are key components of every hard-rock (i.e.,metal/nonmetal/coal) mining operation. Well-executed and maintained drilling and blasting can have a major positive impact on the overall success of such operations. This case study presents the implementation of a new drill and blast engineer position and systematic improvement of the drill and blast operations at a surface metal mine. The findings of and lessons learned from this case study can be applied toother mine operations to improve safety, production, efficiency, and cost savings. Focus areas for the project included refined communications, operational practices and procedures, planning, designing, and data collection and analysis. This case study showed improved efficiency in communication and planning among the engineers, operations team, and contractor groups over the course of the project. An increased awareness of long-term plans and needs for the drills and blasters reduced or eliminated existing delays. Test blasts that implemented new drill and blast designs and updated operational practices and procedures were tested to streamline the process. Constraints regarding explosive product shipments, geological considerations, and a uniform powder factor provided the basis for new blast designs.

By Paul Sainato

Recruiting and retaining students in the explosives industry is becoming increasingly important each year. With no undergraduate degree in explosives engineering currently available in the United States, it is from other industries and degree disciplines we must recruit. The 2014 annual ISEE conference saw the first anonymous online survey distributed to members of SEE student chapters of the International Society of Explosives Engineers. The survey contained questions about future job and career plans, ideal job placement, expectations of salary and current academic degrees. The purpose of the survey was to determine what these students expect or require from a career in the explosives industry, and their current path to pursue this. This information can help steer recruitment activities and job offers for graduating students. The success for both student response rates and interest from the industry has allowed space for a yearly update of this survey. A second survey was distributed in 2015 and included international students. This paper provides the data from a third online survey distributed to all student members of the International Society of Explosives Engineers, globally. Understanding the main incentives for a student to accept a graduate position as an explosives engineer can help us, as an industry; position ourselves to remain competitive in recruiting against other major degree disciplines.

Jan 1, 2016

By Nolan Eckroade, Nigel Pereira

Wireless electronic blasting systems are a new technology that enable truly wireless initiation through rock, air and water. This is achieved using low frequency magnetic induction waves to wirelessly send a firing command to groups of in-hole primers. Fully wireless initiation not only removes the limitations imposed by a wired connection to each primer in a blast, but also enables users to alter the paradigm of conventional mining techniques to advance operational productivity and reduce personnel exposure to high-risk activities. While initially deployed in underground applications, wireless electronic blasting is now being used in the open cut environment. To capture the early impacts in surface mining operations, case studies conducted at three surface mines evaluated blasts utilizing a wireless electronic blasting system against baseline blasts using conventional, wired initiation systems. The purpose of this paper is to outline the specific learnings associated with wireless electronic blasting in surface mining to date. The paper will include references to these specific case studies as well as benefits realized and applications for the future.

By Jason M. Ryan

"Along with recent advances in computer technology have come cost-effective systems desiiedto evaluate fragmentation distributions through digital images of particles. In mining operations andmineral processing plants, important data from these systems is obtained through monitoring sizedistributions at key stages of the comminution process. Blast engineers apply this technology as atool for the validation of empirical fragmentation models so that predicted results are more meaningful."

Jan 1, 1998

By Abraham Lindo

"Blasting plays a key role in hard rock underground mining. It is by nature a violent and destructiveextraction method designed to economically fragment the rock into a suitable size for it to be loaded and hauled as part of the specific mining process while controlling the amount of damage to the surrounding rock mass."

Jan 1, 2016

By A J. Rorke, U Chhika

"A series of tests was carried out on a dry blend of PPAN and LAN prills (LANFO). The objective of thetests was to determine detonation stability and VOD performance compared to ANFO. Heave andfragmentation results in the field were also evaluated visually. A number of factors were behind for.mulating this blend. A lower cost is combined with higher in-hole energies, but at slower reactionrates and lower peak borehole pressures. The resultant effect is improved heave characteristics andlower energy losses caused by inefficient crushing of the rock immediately around the borehole.The test results indicate that IANFO is ideally suited to blasting in softer midburden and overburdenrock types often encountered in coal strip mines."

Jan 1, 1995

By S A. Steyn, P Terrett

Air decking has become a widely practised method internationally for modifying fragmentation results and providing cost savings from reduced explosive consumption. Duvha has been applying air deck technology to overburden and midburden blasting for a few years. A thorough evaluation of air decking at Duvha has been made by instrumenting a number of blasts and analysing costs from direct savings in reduced explosives costs to savings in improved dragline productivity.

Jan 1, 1995

By Thomas M. Keevin, Gregory L. Hempen

"Natural resource agencies, under various regulatory authorities, are challenged with permitting underwater explosive use while at the same time protecting aquatic resources. Deciding on whether or not to allow use of explosives requires striking a balance between development and aquatic resource protection. A company’s goal in underwater explosive use is to select methods that are both expedient and cost effective. The use of explosives is often the best alternative for engineering reasons or economic considerations. Over and above legal requirements, indiscriminate destructionof fish and other aquatic resources is not in a company’s best interests because of concerns relatingto public image, as well as the need to secure future contracts."

Jan 1, 1995

By Clarence R. Zink

A problem has always existed in deep and fast drilling situations such as coal overburden drilling, or when drilling with a tight annulus, such as 9 7/8" bits and 8 5/8" pipe. This problem is the difficulty experienced by blasthole bit and blasthole drill rig manufacturers to attain large jumps in bit and drill rig productivity through bit and rig design, when drilling in these specific situations. In other drilling situations, these large jumps in productivity have been easily attained.

Jan 1, 1998

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 Alastair Grogan

In October of 2002, the author was retained by Public Works and Government Services Canada, on behalf of the Department of National Defense, to design, construct and test the effectiveness of a bubble curtain system at an underwater demolition range, near Victoria, BC. The purpose of the bubble curtain was to reduce the potential for fish mortalities at the site. This paper presents some of the elements of the design, along with the results of overpressure monitoring during blasting and compares the results of fish mortality and animal behaviors with and without the bubble curtain in operation.

Jan 1, 2005

By Tapan Goswami

The expectation from the blasting engineers and shotfirers is often that explosives will perform optimally at all times. However, in reality, non-ideal situations exist on mine sites and occurrences of poor explosives performance are common. Often the cause is difficult to identify. Having a good application technique and analysis skills will minimise the risk of poor performance. This paper will discuss the experiences gained by the author while blasting in the Hunter Valley, Australia.

Jan 1, 2003

By S J. Brace

About 180 000 tons of explosives are used annually underground in South Africa. Most is loaded into holes less than 50mm in diameter. 75% is consumed in the gold and platinum mines where holes are between 25 and 4omm in diameter and no more than 3.0m in length. The small amount of explosives per hole with extreme conditions of heat, humidity and seismic activity, make the choice of explosive on safety and technical grounds very important to the success of a blasting operation. Taken together with the fact that many underground precious metal operations are now marginal then the choice of an explosive, when its price is also considered, becomes critical to the very viability of some mines.

Jan 1, 1994

By Richard Brummer, John Hadjigeorgiou, Patrick Andrieux

Some of the major challenges associated with underground mining at depth and/or under high extraction ratios are related to the resulting high stress levels, which can lead to the failure and collapse of the rock mass surrounding the excavations. Sudden and violent failures, which can have severe consequences, represent the highest degree of difficulty in terms of underground personnel exposure, erratic and unpredictable production, ground rehabilitation requirements, possible reserve losses and overall mining costs.

Jan 1, 2012

By Michael S. Wieland

Toxic fumes cause fatal and nonfatal incidents in underground mining, where the working environment tends to trap the fumes, hindering the restoration of nonharmful 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. Hole-to-hole shock waves and rift compressions can partially desensitize charges, ruin the reaction kinetics, and worsen the fume toxicity. Traditionally the fume hazards for candidate explosives are resolved for a restricted set or tally of theoretical or measured fume components, transformed to standard reference conditions. The relative fume toxicity RFT is the resultant influence reckoned from a formulated sum of concentrations within the tally that are unweighted or weighted with chosen multiplying constants. The RFT result is compared to a rule criterion that represents the worst case tolerable fume toxicity stipulated by regulations or otherwise. The ranking and comparison of different hazard potentials that would otherwise remain unwieldy is rendered tractable by the common format of the RFT notation.

Jan 1, 1998

"Rock falls involving a relatively small amount of material are a leading cause ofinjuries in underground mines in the United States. A contributing factor is unwantedblast damage and over-break. A goal of the United States National Institute forOccupational Safety and Health is to reduce the number of ground fall-related accidents by improving drift driving practices through the introduction of perimeter control blast designs. This paper presents a blast design technique based on a hydrodynamic method. Using commonly available explosive and geometry data, the theoretical particle velocity is calculated as a function of distance away from a cylindrical charge. A calibration factor is introduced to account for actual conditions by comparing the predicted values to a set of field data. The calibrated curve can then be applied for design. The paper introduces modifications to account for different explosives from those used in a calibration test. The application of the approach is demonstrated with respect to a data set from a large-scale concrete block test."

Jan 1, 2009