Search Documents

By D. Bois, P. Keating, J. Lemieux, M. A. Vallée, M. Allard, R. S. Smith, L. Z. Cheng, M. Chouteau, D. K. Fountain

"Abstract - MEGATEMII airborne electromagnetic data collected over the Iso and New Insco massive sulfide deposits have been modeled using three modeling packages. The EMQ package is a quick inversion tool which indicates that the Iso body is a dipping, plate-like body. The New Insco body is inferred to have a geometry somewhere between a dipping plate and a sphere. The Maxwell package was used to refine the properties of the plate-like body at Iso. The EMIGMA package was able to identify which parts of the New Insco orebody were more conductive. It was observed that the most conductive parts correspond to copper-rich zones and the next most conductive to pyrite-rich zones. The EMIGMA package was also used to show that a thick-prism model might be more appropriate for the New Insco orebody. Gravity modeling constrained by the known geology was successful in identifying the denser sulfide zones. The densest zones appear to be pyrite rich. Magnetic modeling identified diabase dikes. Over New Insco, a small magnetic anomaly was attributed to pyrrhotite-rich sulfides. There was only a weak magnetic anomaly over the Iso body, consistent with the nonmagnetic sulfides logged in the holes drilled at that location. Sommaire - Les données MEGATEMII recueillies au-dessus des dépôts d’Iso et de New Insco ont été interprétées en utilisant trois outils de modélisation différents. L’outil EMQ a été utilisé comme un outil d’inversion rapide suggérant que le dépôt Iso peut être considéré comme une plaque inclinée, et que le dépôt de New Insco se situe quelque part entre une plaque et une sphère. L’outil Maxwell a été utilisé pour raffiner les propriétés du dépôt Iso. L’outil EMIGMA nous a permis d’identifier les différences de conductivité à l’intérieur du dépôt Iso. Il a été observé que la partie la plus conductrice correspond à la zone riche en cuivre, suivie par la zone riche en pyrite. L’outil EMIGMA a aussi permis de montrer qu’un modèle de prisme épais pourrait être plus approprié pour décrire le dépôt New Insco. La modélisation des données gravimétriques, contrainte par la géologie connue, définit bien la zone de sulfures massifs. La zone de pyrite semble être la plus dense. La modélisation des données magnétiques identifie bien les dykes de diabase. Au-dessus du dépôt New Insco, on observe une faible anomalie magnétique correspondant aux sulfures non magnétiques observés dans les carottes de forages à cet endroit."

Jan 1, 2006

By L. St-Georges

In aerospace and transportation industries, severe problems are related to fatigue failure. Aluminium is frequently used in these industries to optimize the solidity and minimise the weight of the structures. Nevertheless, the fatigue life of aluminium alloys is limited and specific efforts have to be made to reduce the vibratory stresses in the mechanical parts. When riveted, the life of the sheet metal structures can be increased compared to welded structures, due to the energy dissipated by the friction between the rivets and the sheet metal and the sheets themselves. In the past decade, a new tool was developed to assemble aluminium structures; the friction stir welding. With this new technique, fatigue life of the aluminium welded joints can be increased by a factor from two to ten. However, less energy can be damped by the friction between the components and increased vibratory stresses may occur. In this investigation, the potential of the friction stir welding to create damped aluminium sheet metal structures is evaluated.

Jan 1, 2006

By Ralph Harris, Javier Jara

"Oxygen is essential in gold cyanidation. It is supplied to the leaching media by sparging oxygen or compressed air into the cyanidation tank. The rate of oxygen transfer is critical to achieve the desired oxygen concentration in solution.The performance of a novel device for gas sparging recently developed at McGill University is compared to the mass transfer characteristics of the two spargers most used in the gold industry: the four lance configuration and the inverted cone. The distribution of gas and the kinetics of oxygen desorption of the three types of spargers was studied in a 140 litre tank. The oxygen dissolution of the new device is three to five times faster than the other spargers. This could increase the leaching rate and/or decrease the cyanide and oxygen consumption.IntroductionIn hydrometallurgical processing, it is often necessary to bubble gas through a pulp to carry out the wanted reactions. The gas can act to agitate the pulp and it can also supply reactant. The rates of the reactions which require a reactant supplied by the gas are often dependent on the rates of mass transfer from the gas to the solution.A common example of this is gold cyanidation which requires oxygen for gold dissolution. Since the gold containing slurry is rich in other oxygen consuming substances (sulphide like pyrrhotite), it is important to provide enough oxygen to allow complete gold dissolution within the residence time of the cyanidation reactors. It has been demonstrated that the rate of gold dissolution is directly proportional to the dissolved oxygen concentration of the pulp which in turn is proportional to the oxygen partial pressure in the bubble 1 2 3. Improving the rate of mass transfer of oxygen increases the dissolved oxygen concentration of the slurry and therefore improves the rate of the reaction.The rate of mass transfer from a bubble to its surrounding solution increases with decreasing bubble size and increasing gas bubble residence time which in turn increases with decreasing bubble size. The generation and dispersion of small bubbles is thus critical to achieving high rates of mass transfer. Different configurations and devices used to inject gas have different effects on the bubble size and the residence time, influencing the overall rate of mass transfer. Therefore better mass transfer can be achieved by adopting a more efficient method.The methods tested in this report are the four lance configuration (wall spargers), the inverted cone and a new device, designated HCD. The wall spargers and the inverted cone are used widely in the industry today."

Jan 1, 1994

By Chunfeng Zhao, Chong Bao, Cheng Zhao, Jiashen Tian, Matsuda Hiroshi

"Based on digital image correlation (DIC) method and self-developed code, the global strain field changing and failure properties of rock-like materials with pre-existing double flaws are experimentally studied under uniaxial compression. By theoretical analysis with linear elastic fracture mechanics (LEFM), the strain approach proves to be practicable to investigate cracking process. Thus, two types of process zone are defined to discuss the specimen’s coalescence evolution at different loading stages. Crack initiation, propagation, and coalescence is a process of zone development and nucleation. DIC strain field results are studied on a meso-level using a strain approach. In the shear coalescence mode, the SPZ (shear process zone) in a bridge area coalesces with each other, while the TPZ (tensile process zone) grows independently. In general, the paper tries to establish the link between microscopic mechanical mechanisms and macroscopic mechanical responses in flawed rock. Further research should be done to study the cracking process and its effect on rock strength in detail by the DIC method.INTRODUCTIONNatural rock contains discontinuities including pores, fractures, inclusions or other defects. The existence of these discontinuities in the rock can decrease the strength and stiffness of the rock and they are a source of initiation of new discontinuities which may in turn propagate and link with other cracks and further decrease the strength and the stiffness of the rock (Sagong & Bobet, 2002). Lots of theoretical, experimental and numerical researches have been done in studying crack initiation, propagation and coalescence in rocks (Hoek & Bieniawski, 1965; Kranz, 1983; Reyes & Einstein, 1991; Park & Bobet, 2009; Gonçalves & Einstein, 2013). But when it comes to multiple pre-flaws, the issue that how the preexisting flaws affect each other becomes complicated and uncertain. The stress field around the tips of flaw can either enhance the impact of single flaw or weaken it. According to the observations have been done before, it is found that the way and function in which these cracks propagate and coalescence depends on the geometric arrangements (Bobet, 1997; Bobet & Einstein, 1998; Wong & Chau, 2001)."

Jan 1, 2015

By Michael McClintock, Bern Klein

"The high pressure grinding roll (HPGR) is a relatively new comminution technology that is gaining popularity for providing energy efficient solution to hard rock mining operations. A significant barrier to increased adoption of HPGRs is the present requirement for large amounts (excess of 2 tonnes) of sample for pilot testing, which may not be possible for most early stage projects. Three methodologies have been developed at NBK Institute of Mining Engineering at the University of British Columbia that may be used for sizing design optimization of HPGR circuits. All three methodologies use a MTS pistonpress to simulate HPGR comminution. These tests are capable of providing information regarding energy consumption, energy breakage relationship, reduction ratio, and product size distributions. In a period of slow economic development, these methodologies are critical to allow the industry to cost effectively understand the operational benefits of HPGR implementation. This paper examines previous test work done at UBC, as well as the development of an HPGR and piston press database for use in sizing and budgeting of HPGR circuits.INTRODUCTIONCurrently, the mining industry faces several challenges due to falling commodity prices and escalating costs. This has applied pressure for operations and projects to reduce costs and improve project economics. In addition engineering and metallurgical budgets have shrunk as companies try to conserve cash. Improvements and optimization of milling and comminution circuits is one area project economics may be significantly improved. By considering alternative comminution technologies such as the high pressure grinding roll (HPGR), energy operating costs may be greatly lowered. Many have begun to implement HPGR crushing as an alternative to semi-autogenous grinding (SAG) mills, including KGHM and, Sierra Gorda, and Freeport Mc-MoRan’s Cerro Verde operation. However, implementing new technology for companies with little or no HPGR experience may not be practical. An operator must consider both feasibility and economics of a circuit. Currently, consideration of the HPGR requires expensive pilot scale testing for which large sample sizes are needed. In addition, few laboratories are equipped for running pilot scale HPGR test programs. Furthermore, the results of pilot HPGR testing are dependent on the quality of the sample, which cannot represent variations across a deposit. In contrast, ball mills and SAG mills can be sized using the Bond Mill Work Indexes that require a small amount of sample which enable a number of different geological blocks to be tested to allow engineers to have a complete understanding of how the comminution circuit will perform for the life of mine."

Jan 1, 2016

By John R. Hayes, Kebbi A. Hughes, John Rowson, Peter E. R. Blanchard, Jeremiah C. Beam, Andrew P. Grosvenor, Arthur Situm

Uranium ore bodies contain elements within mineral phases that need to be disposed of responsibly. Solid waste can be placed in a tailings management facility (TMF) to contain the waste elements and limit interactions with the environment. It is important to understand how the chemistry of the tailings evolves throughout the lifetime of the operations that feed the TMF and after the site has been decommissioned. The objective of our collaboration with Orano Canada was to study how the tailings from the TMF located at McClean Lake, Saskatchewan change over time. This manuscript discusses our use of X-ray absorption spectroscopy (XAS) and X-ray microprobe to study the fate of Mo and Ca in the tailings. Mo is considered an element of concern (EOC) and it is necessary to determine if a stable solid Mo-bearing species forms. Thermodynamic modeling suggested that aqueous Mo would precipitate over time as powellite (CaMoO4). Comparing Mo K-edge XAS spectra from the solid tailings to the aqueous Mo concentration in the pore water showed that powellite did form and that this did result in a decrease in the aqueous Mo concentration over time. Further, it has been proposed that Ca2+(aq) can react with bicarbonate ions in the pore water and precipitate as calcium carbonate (e.g., CaCO3). This reaction would limit the aqueous bicarbonate present in the tailings that could react with uranyl ions to form soluble uranyl-carbonate complexes. We have identified several trace Ca-bearing species, including carbonates, in the tailings using XAS and X-ray microprobe.

Jan 1, 2020

By Xiaoguang Zhao

The coal mining area in Northern Shaanxi, China, has been taken as the study area, and the damage mechanism of the ecological environment is discussed on the basis of analyzing the characteristics of natural eco-environment and resource development in this area. Mining subsidence is taken as an example, and by using the Gray Correlation Analysis method, the key impact factors have been selected. An assessment model with fuzzy comprehensive evaluation has been constructed, and 12 coal mines have been quantitatively assessed. This paper also constructs an ecosystem health assessment method and index system in the coal mine area on the basis of ecosystem health theory, and assesses the ecosystem health status in the Shenfu coal mining area from 2000?2006. The research results are expected to help the eco-environment protection process in the designated coal mining area.

Aug 1, 2013

By V. S. Papezik

Pyrophyllite, a hydrous aluminium silicate, is used mainly in the ceramic industry and to a lesser extent as a filler in the manufacture of paper, rubber, insecticides and baby powders. Commercial deposits of pyrophyllite in North America are restricted to the "Avalon Zone" , a belt of late Precambrian volcanic and sedimentary rocks that extends along the eastern flank of the Appalachian orogenic belt f rom Georgia to Newfoundland. The only commercial Canadian pyrophyllite deposit lies near Foxtrap on the A valon Peninsula of Newfoundland. Here, steeply dipping lenses of altered pyrophyllite rock occur in a north-trending rhyolite belt near the contact with a granitoid pluton. The altered rock is massive, light greenishyellow and contains varying proportions of pyrophyllite, sericite and quartz with lesser amounts of diaspore and traces of barite and rutile. A lteration was produced by acid solutions, either derived from or activated by the intruding pluton, at temperatures of 250° to 270°C and pressures not exceeding 2 kbr. The largest of the Foxtrap pyrophyllite lenses, discovered in 1897, was mined intermittently f rom 1903 until the early 1950s. The present owner of the mine, Newfoundland Minerals Limited, acquired the property in 1959 and ships between 27, 000 and 36,000 tonnes annually to th e company plant in Lansdale, Pennsylvania, for use in ceramic tile.

Jan 1, 1984

This paper describes results of an investigation of fracture during tube expansion of 5052 and 5754 aluminum seam-welded tubes to optimize the forming of aluminum tubes during hydroforming. The tubes were produced in laboratory by press forming of tubular blanks and pilot-scale high frequency induction welding. The effect of property mismatch between the weld and base metal has been investigated. The material work-hardening was obtained by roll forming of sheet blanks in the 0-temper and H32 temper condition. The results showed that a significant work-hardening can be present in aluminum tube without causing weld fracture during tube expansion. The work-hardening increases the yield-strength mismatch between base metal and weld. Annealing reduces the hardness of base metal leading to more uniform deformation during tube expansion. As a result the occurrence of weld fracture is reduced. The study showed significant deformation of the welds during tube expansion. Weld thinning can be as large as parent-material thinning before fracture. To avoid fracture at the weld joint, good formability and high yield strength of the weld is needed. FEM simulation showed that minimizing the width of the weld joint can reduce thinning of the weld.

Jan 1, 2004

By Real Daigneault, François Robert, J. Paul Golightly, Jean-Yves Cloutier, Jayanta Guha, Pierre Pilote

"The Casa-Berardi East, Center and West deposits, located in the Archean Abitibi, Sub province, are hosted by volcanic and sedimentary units of varying compositions, less than300 m from the Casa-Berardi fault (CBF). The CBF, a brittle structure, represents an increment in the structural evolution of a regional-scale deformation zone showing ductile-brittle behavior known as the Casa-Berardi deformation zone (CBDZ). The CBDZ is characterized by a mylonitic Sc1 foliation which is folded a.n4 deformed by a later sczfoliation in high strain zones.Four generations of quartz vein and fracture systems have been recognized within the Casa-Berardi deposits. Most economic gold mineralization, occurring in the second generation system, is found within high strain zones. This system hosts three types of mineralized structures: (1) banded quartz veins; (2) swarms of veins and mineralized host rocks; and (3) disseminated sulphides along fractures. An early carbonate hydrothermal alteration zone (pre- to syntectonic) surrounds the deposits. Alteration associated with gold mineralization is contemporaneous to late ( syn- to post-tectonic) relative to the development of progressive deformation in the CBDZ. The geological characteristics and paragenesis of the four quartz vein and fracture systems developed as an integral part of the geodynamic evolution of the Casa-Berardi deformation zone."

Jan 1, 1990

"This document establishes standards and guidelines for scientific and technical disclosure by Issuers listed on the TSX Venture Exchange on their mineral properties. It incorporates and expands upon the minimum standards prescribed by Securities Laws and applies to all oral statements and written disclosure made by an Issuer or on behalf of an Issuer involving mineral properties.1. Introduction1.1 General(a) This Appendix establishes standards and guidelines for scientific and technical disclosure by Issuers on mineral properties. These standards and guidelines should be applied prudently and with common sense by those Issuers in conjmction with the applicable requirements of section 1.2.(b) This Appendix incorporates and expands upon the minimum standards prescribed by Securities Laws and applies to all oral statements and -written disclosure made by an Issuer or on behalf of an Issuer involving mineral properties.(c) This Appendix is not intended to be exhaustive or all-encompassing and greater detail may be appropriate and required in certain situations. Issuers are encouraged to contact Exchange technical staff where they are not certain about the requirement for disclosure on mineral properties."

Jan 1, 2003

By Richard K. Komarek, Antonios Zavaliangos, Roman T. Dec

Current industrial compacting and briquetting practices are largely based on trial-and¬error techniques. This paper introduces a two dimensional finite element model of compacting/briquetting process in the roller press. Compared with other modeling techniques used in the past, finite element method offers the most versatile approach because it incorporates adequate information about powder behavior, geometry and frictional conditions and offers predictions for the density distribution, velocity field, stress distribution, roll force, roll torque and other important process variables. More over, when the model includes elasticity, it offers predictions on the internal stress state in the briquet after its exit from the pressing zone. This enables to perform realistic computer experiments which are helpful for establishing the pressing system design, forming cavity geometry and process conditions necessary to produce compacted or briquetted product with the desired properties.

Jan 1, 2004

By A. Tikhonov, D. Kipper, V. Korovin, A. Olifirenko, Yu. Shestak

The present paper deals with vanadium and molybdenum sorption from industrial wastes and intermediate processing products using Cybber macroporous strong- and weak-base anionites. Vanadium and molybdenum recovery by Cybber anion-exchange resins as well as desorption processes were studied in static and dynamic modes; their efficiency was demonstrated for that purpose. The results of the work may be used to design technologies for complex processing of both ores and industrial wastes containing vanadium and molybdenum.

Jan 1, 2011

By Angus D. Campbell

Introduction Gowganda forms part of the general Cobalt area. Its rocks and ores are very similar to those of the other parts of the area. While its total production of silver is only 4 per cent of that of the famous Cobalt silver camp, its 1928 shipments contained 42 1/2 per cent as much silver as those of Cobalt for that year. During twenty years of production, 15,000,000 ounces of silver have been shipped from Gowganda. Of this, over 8,000,000 ounces have been shipped in the past five years. The area has thus made for several years a substantial contribution to the wealth of Ontario. Its future depends to a great extent on the priee of silver, which is now, unfortunately, at a record low price. This paper is a discussion of how the Gowganda ore-shoots occur, together with some notes on the milling of the ores at the Castle-Trethewey Mines. The first part is written in the hope of stimulating further study of the silver occurrences, which may lead to further discoveries. The second part, besides being a matter of record, may be of some use to operators of small mills. The drawings in the several Figures illustrating the text are by W. D. Stroud, mine superintendent of the Castle-Trethewey Mines, the benefit of whose opinions I have had in compiling these notes.

Jan 1, 1930

By Paul G. Dunn

The planning of underground mines is a complicated process involving geological, engineering and operational constraints. MIRARCO is in the process of developing a 5D Mining Exploratorium where 3D mining models are combined with time (4th dimension) and costs (5th dimension). The mining exploratorium is a collection of external and inhouse software packages specifically geared to help underground mining companies arrive at better mine plans. This paper discusses the progress made in the development of the 5D Mining Exploratorium and a change in mine planning philosophy by conducting frequent audits in a Virtual Reality Laboratory. The development of genetic algorithms for optimising stope sequences is also presented.

May 1, 2003

By George B. Saunders

It is the purpose of this paper to point out conditions as they exist in the merchandizing of coal, to compare these conditions with methods in use by competitive producers of coal substitutes, and to present briefly some suggestions which may help the individual operator to market more coal in the immediate future, while we are waiting for the scientist and research worker, who are now busy on coal betterment , to produce in a practical way the results which they now write about in such glowing terms. While it may be unnecessary to call the attention of coal operators to the present deplorable condition of the industry, it might be well to impress upon our members in other branches of mining, as well as upon the public at large, the seriousness of the situation. Emerging from the war and the period of reconstruction that followed, the coal industry found itself with too many mines and too many men for normal conditions. To make matters worse, the interruptions in deliveries caused by strikes, the unfavourable publicity caused by socialistic propaganda, and the repeated governmental investigations, made the market a fertile field for coal substitutes which were not so handicapped. These substitutes were well advertised, and were marketed in an up-to-date manner, furnishing an example from which the coal operator could well profit. Now, whether or not there is agreement as to the cause or causes of this condition, there can be no doubt that we are today face to face with the fact that the sale of coal has not kept pace with the sale and use of other commodities. Had it done so, we would ere this have been able to take care of the surplus labour and work our mines at least approximately full time.

Jan 1, 1929

By R. E. Legg

This paper gives a brief outline of the mining and milling methods which will be used on the Stirling zinc-lead-copper ores by Stirling Mines, Limited, who have for the past two years been developing the Stirling mine in Richmond county, Nova Scotia, and who will bring the mine into production in November, 1929. No attempt has been made to give the paper a detailed technical character, for the main reason chat, since base-metal mining is something new in Nova Scotia, it is felt that a general description would be preferable before this Society, whose membership is mainly made up of chose engaged in the coal mining and associated industries. Furthermore, as both mining and milling operations will be governed to a certain degree by the experience gained after production commences, there are many points which cannot be definitely stated now. GEOLOGY Before discussing the mining methods, it is desirable to present a general picture of the geology and occurrence of the ore-bodies. The surface rocks in the vicinity of the mine consist of rhyolites of .pre-Cambrian age. These volcanic flows outcrop in very few places, usually along' the beds of creeks or on the shores of the numerous small lakes. Consequently, a detailed geological map is not available. The exploration work carried out to date has revealed a sheared zone extending through the volcanic flows for a distance of over 1,000 feet. Along this zone, there has been a replacement of the rhyolites by a carbonate rock for widths varying from 50 to 230 feet, and it is in this carbonate formation chat the mineralization at a later date took place.

Jan 1, 1929

By C. L. Reichardt

Pressure exerted on gold producers by regulators, project financiers and civil society in the wake of the Baia Mare tailings spill in Romania during 2000 prompted most responsible gold companies to sign up to the International Cyanide Management Code for the Manufacture, Transport and Use of Cyanide in the Production of Gold (the Code). The Code stipulates a ?cradle to grave? approach more comprehensive than that applied to any other mining reagent and poses particular challenges for operators who use cyanide-bearing tailings for backfill. This paper examine some of the challenges for Code compliance facing deep underground gold mines that employ backfill technology, most particularly the requirement to demonstrate that the potential migration of cyanide (and its degradation products) from emplaced backfill will not have an unacceptable impact on worker health and safety or the receiving environment, either during mine life or after closure. Although the Code only contains a single reference to backfill, more careful consideration confirms that most sections of the Code that deal with tailings management are potentially applicable to mines where tailings material is used for backfill, as are certain principles pertaining to aspects of operations, worker safety, emergency response, training and dialogue with stakeholders. For gold mines of the Far West Rand, the most significant cyanide-related risks associated with backfill operations relate to worker exposure to cyanide-bearing seepage and HCN gas. There is potential for seepage of cyanide-bearing water from backfill to compromise the beneficial use of surface and groundwater, and thus impact on downstream users and ecosystems. However, the extreme depth of mining and the specific geological and hydrological controls on the Far West Rand suggest that the potential environmental risks associated with backfill are likely to be considerably less significant than the cyanide-related risks to the workforce.

May 1, 2007

By T. R. Eger

Miners can be exposed to whole-body vibration (WBV), when sitting or standing to operate mobile equipment. In order to prevent vibration-induced injury it is important to understand how miners can be exposed to vibration, the health risks associated with vibration exposure, methods to evaluate vibration exposure, and strategies to reduce vibration exposure. WBV exposure typically occurs when operating mobile equipment, such as a load-haul-dump vehicle, haulage truck, or dozer. The probability of health effects such as low back pain, neck pain, headaches, and gastrointestinal track problems occurring from daily vibration exposure can be determined based on criterion values published in ISO 2631-1 and EU Directive 2002/44/EC. A special case of WBV termed foot-transmitted vibration (FTV) occurs when a miner is exposed to vibration that travels through the feet. FTV typically occurs when standing on vibrating surfaces associated with the operation of locomotives, jumbo drills, bolters, or raise platforms; however, there is no set standard to evaluate health effects associated with FTV. Recent medical evidence confirms workers exposed to FTV can develop cold induced blanching of the toes, in addition to numbness and tingling in the feet and toes. In order to reduce the risk of adverse health effects from exposure to vibration, the hierarchy of controls (elimination; substitution; engineering; administration; and personal protective equipment) should be followed. Best practices should be used to minimize vibration exposure through equipment purchases (i.e. vehicles with lower vibration emissions and seats that attenuate vibration), reduced driving speeds, and improved road maintenance for example. The elimination of other risk factors, which increase injury risk when combined with WBV exposure, such as awkward working postures, should also be eliminated. Very little is known about FTV exposure therefore further research is required in order to develop exposure standards and identify prevention strategies.

Aug 1, 2013

By Rene A. Morin, John K. Kebe

"As explosives become more widely used in urban and other congested areas, governmental regulations pertaining to their use are becoming more pervasive and stringent. This is forcing the blasting industry to review its entire spectrum of operations. Greater attention is now being paid not only to the design and layout of blasts, but also to the monitoring and recording of their after-effects for both legal and business reasons.Current PracticesThe major users of explosives in urban areas are quarry operators and construction companies. A characteristic of both of these industries, at least in recent years, is a relatively low margin of profit. This, coupled with the fact that their use of explosives is relatively intermittent, prevents them from having the kind of professional consulting services that blasting operations really warrant in today's regulatory environment. When such services are obtained, they tend to be directed more at the design and execution of the blast than at the recordkeeping function. The records that are kept tend to be more in the form of a summary of the consultant's design data as opposed to the kind of after-effect detail that is necessary.The more experienced consultants and operators now realize that at least as much attention must be paid to the record-keeping as to the design work. Regulatory bodies at all levels of government are insisting on the availability of such records.Unfortunately, the instrumentation in use today for taking such measurements does not lend itself to the practice of intermittent consulting. Current monitoring and recording instruments are based on so-called analog technology of the type that has traditionally been applied to the monitoring of earthquakes. They require set-up and calibration procedures which must be repeated each time the instrument is moved, or the blasting parameters are changed, as well as complex total analysis of the recorded data. This can lend to confusion and a dilution of responsibility for anything other than the design work and possibly some summary reporting."

Jan 1, 1985