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By N. Katsikaros, A. Lewis-Gray, P. Richards

"To optimize gold recovery in complex leach-to-electrowinning processes, Gekko Systems developed the Gekko resin exchange column (G-REX) as an intermediate step, using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin. Operational experience has been gained at the Castlemaine Goldfields Ballarat gold mine. In near-continuous operation since 2008, the Ballarat plant treats unclarified concentrate leach solution. The extension of this technology to higher throughputs and more complex chemistry is discussed.RÉSUMÉ Afin d’optimiser la récupération de l’or dans des procédés complexes impliquant la lixiviation suivie de l’extraction électrolytique, Gekko Systems a développé la colonne Gekko de résines échangeuses d’ions (G-REX) comme étape intermédiaire, à l’aide d’une résine hautement sélective pour la récupération de l’or qui permet d’isoler les métaux contaminants. Gekko détient la licence exclusive pour la résine AuRIX®100 produite par Purolite, et la colonne G-REX a été spécifiquement conçue pour cette résine. C’est à la mine d’or Ballarat de Castlemaine Goldfields que l’expérience opérationnelle a été acquise. L’usine de Ballarat, en exploitation quasi-continue depuis 2008, traite une solution concentrée non clarifiée de lixiviation. L’extension de cette technologie à des capacités supérieures et à une chimie plus complexe est examinée.AURIX®100 RESINAuRIX100 resin is a crosslinked polystyrene alkaline resin developed by Henkel (Virnig, Mackenzie, & Adamson, 1996). The resin beads are off-white in colour and spherical, with a nominal size of 100% +600 µm. This resin is highly selective for gold and silver over many metals, by way of extracting precious metal–cyanide complexes from leach solutions with a pH of less than 11.5. The higher end of the pH scale produces the best selectivity according to the order of preference: Au > Ag > Hg > Zn > Ni > Cu > Co > Fe. Purolite produces the resin and Gekko Systems maintains licensing of AuRIX100 resin for use in its G-REX column, as part of its unique suite of gravity gold–handling equipment.Significant cost savings over carbon-in-solution (CIS) systems are realized with AURIX100 resin: approximately 4–12% in capital savings and 27–40% in operating costs (Virnig, Mackenzie, Katsikaros, & Gray, 2004). Additionally, AuRIX100 resin is not susceptible to fouling; that is, the resin does not load with inorganic salts or organic compounds that would affect the loading and extraction of precious metals. To counter any potential for fouling by inorganic salts, a dilute acid wash is periodically conducted in service on the resin to unblock resin pores."

Jan 1, 2017

By N. Ahern, L. Manoukian

"Cyanide is a leaching agent for precious metals commonly used in gold ore processing. Cyanide exists in various forms (including free, complexed as weak or strong complexes, and as ions such as cyanate and thiocyanate), so its detection, speciation and analysis in processing or environmental samples can be complex. This paper will review best practices for cyanide sampling and preservation in the field, interferences and pretreatment methods required prior to sample analysis and analytical methods that are used for cyanide species. Titrimetric, flow injection ligand exchange, spectrophotometric, colorimetric, potentiometric, amperometric, and chromatography techniques will be discussed and their chemistries, detection limits, advantages and limitations will be described.INTRODUCTION Cyanide is well known to be an extremely toxic species. Accurate cyanide measurement in effluent from mines is critical from an environmental perspective. Its measurement is also an important control parameter in the recovery of gold using cyanidation. Cyanide chemistry is diverse and complex, and cyanide analysis can be challenging as a result of and because of limitations in understanding of analytical methods. Various chemical mechanisms can form or destroy cyanide, and the sample matrix or preservation chemicals can also affect analytical results. These interferences make the collection of reliable cyanide measurements challenging and can start as soon as the sample is collected, during laboratory pre-treatment and during analysis. This paper reviews different methods of cyanide measurement. The basic chemistry of cyanide, best practices for sampling and preservation, as well as various methods of analysis will be discussed.CHEMISTRY The complexity of cyanide chemistry is well known (Beck, 1987; Delgado, Botz, Bucknam, Milasovljevic, & Staley, 2008; Botz, Milosavljevic, & Ward, 2013) and is attributed to the ability of cyanide to undergo: •,Volatilization •,Precipitation •,Adsorption •,Complexation with metals •,Oxidation to cyanate, ammonia, or cyanogen chloride •,Reaction with sulfur or sulfide minerals to form thiocyanate •,Redox reactions leading to the formation of cyanogen and cyanate •,Redox reactions (of some cyano complexes) •,Photochemical reactions (of some cyano complexes)"

Jan 1, 2017

By David R. Winfield

I would like to thank you for spending the time with me today to review the FLIR PathFindIR thermal imaging camera system: It is truly an innovative safety system that has the added benefit of offering increased efficiency Our company the Winsted Group, specializes in mobile video systems that are fully customizable to address standard and unique operational requirements in a variety of industries from heavy equipment cameras to police and military digital recording systems, high end video camera systems are a hallmark of Winsted?s product line. The use of thermal imaging camera systems to enhance mobile safety is a relatively new concept as it relates to their use in both transportation and heavy equipment operation. This technology, like so many before it, has been adopted for civilian use from its military roots. The identification of enemy combatants through their heat signature has given our troops a decisive edge in military operations in total darkness Likewise, the ability to discern people and objects that give off heat is a significant step forward in collision and accident avoidance. The PathFindIR camera system that I am demonstrating today is so advanced that it cannot be exported outside of continental North America without a US government approved export license I would like to commence my presentation with a short video clip that discusses the technology associated with the FLIR PathFindIR Thermal Imaging camera systems. The video demonstrates the operational effectiveness of thermal imaging camera systems installed on a vehicle operating on the roadway at night, of course there are definite parallels to use in a mining environment, primarily the fact that lighting is limited and the chance for vision limiting dust is ever present. We are, of course more concerned with personnel safety in our mines than encountering wildlife on the roadside. From the same perspective, the transport driver is just as concerned with encountering a stalled vehicle as our mine truck operators are with other mine traffic.

Feb 1, 2008

By Yvon T. Maurice

Under the auspices of the Federal-Provincial Uranium Reconnaissance Program, a geochemical orientation survey was undertaken in an area of uraniferous Lower Proterozoic (Aphebian) rocks near Cape Dorset in southwest Baffin Island. The main objective of this study was to establish a methodology for a future reconnaissance geochemical program using lake samples over a 300-mile Lower Proterozoic rock belt that occurs along the southern coast of Baffin Island. Mineralogical and chemical studies of known radioactive occurrences, combined with detailed sampling of secondary environment media in the vicinity of the showings. indicate that uranium is the most significant pathfinder, despite considerable enrichment of other metals in the uraniferous rocks, Significant geochemical patterns produced by uranium in lake waters and uranium in lake sediments have been obtained, but their relative usefulness depends on the distribution of carbonate bedrock, which in turn affect the bicarbonate content of lake waters. In southern Baffin Island, because of erratic variation in lake-water alkalinity, it is recommended that both water s and sediments be sampled on a routine basis. The need for lake-water acidification to prevent depletion of soluble metal ions in samples resulting from adsorption on the walls of the containers and/or suspended solid matter is discussed briefly. The base metal potential of the area was examined in some detail and found to be significant, particularly for a Lower Proterozoic gossanous formation that occurs throughout southern Baffin Island.

Jan 1, 1977

By T. G. Joseph, A. Chamanara

ABSTRACT: The chicken and egg scenario — where adverse truck motions cause ground deterioration and poor ground profiles cause adverse truck motions — is a downward deterioration spiral dominating our industry. If we remove one action, the reaction stops. A simple truck to excavator load data analysis and wireless communication system is outlined, which will provide visual assistance to the excavator operator in achieving improved load placement and balance in a truck body. This will reduce subsequent hauler duty cycle adverse motions and g levels that contribute to structural fatigue, higher tkph, reduced tire life, and ongoing maintenance of haul roads.

Jan 1, 2012

By Ajit K. Sinha

"Abstract - Electromagnetic surveys were conducted over the Yava sandstone-hosted lead deposit in Nova Scotia to evaluate the usefulness of such surveys for detecting and mapping sedimentary­ hosted metallic ore deposits. Both transient and multifrequency systems were used for that purpose. The deposit consists of three zones of disseminated galena which also contain minor amounts of pyrite and sphalerite filling the interstices of the sandstone grains. Each zone overlies a basement depression and is separated from the adjacent zone by an intervening basement high. A conductive shale layer underlies the galena-rich sandstone formation at all three zones.Because the concentration of galena (3% to 4% ) and other sulfides is too low to affect the resistivity of the sandstone formations for detection by ground electromagnetic (EM) methods, the strategy for our survey was to look for areas of basement depressions and the presence of conductive shale in those depressions by EM depth soundings. The presence of the galena-rich sandstone formations could be inferred because of the close association of these two features with the deposits in the Yava area. Both transient and multifrequency EM systems were successful in mapping the basement depressions and detecting conductive shale at the three known mineralized zones. The technique, therefore, seems to offer good prospects for mapping similar stratabound sedimentary-hosted sulfide deposits."

Jan 1, 1993

By Ree Llewellyn

"It has been estimated conservatively that the costs of wear damage and friction in the Canadian mining and mineral processing industry amount to over one billion dollars per year. These are mainly incurred through the repair or replacement of worn parts and production losses from related equipment downtime. The selection and application of the most appropriate wear protection components and systems, can thus have a very significant influence on productivity, profitability and global competitiveness.Details are presented of the wide diversity of materials used to counteract the varied and often complex wear attack mechanisms that occur in surface mining. The majority are various forms of steels and irons with generally very high hardness. However, they also include relatively soft elastomers and polymeric products.The main characteristics and applications of the different classes are reviewed. Case studies record significant performance improvements achieved through more judicious selections. Finally, some new developments which reduce maintenance charges by substantially increasing wear component life, are described."

Jan 1, 1996

By C. Graham

Mechanisation has been a predominant theme of the past 50 years in the mining industry, particularly underground mining. As the level of technology employed has increased, the anticipated productivity gains have not been realised and the differences are not explained by the demand for higher standards of safety and security. Now, mining costs are so high and productivity so low that the resultant return on investment for many Canadian operations has fallen to levels considered unacceptable in a competitive capital market. Simply continuing technological development cannot reverse this trend and its financial implications. The focus on technological development has distracted us from some basic truths. Systems that are more complex are more likely to fail and cost-effective processes depend on the continuity of productive activity and the flow of material. When putting these facts together, it becomes clear that in a system that has fixed external conditions, the single most crucial issue is the effective management of the operational cycle. By its nature, technology focuses our attention on what gets done and how it gets done, while the crucial issue is the increasingly longer periods in the operational cycle when nothing productive is being done. What is required is to match the level of technological complexity to the fixed system conditions, which are virtually unchangeable. This paper looks at the overall system and objectives and attempts to present an appropriate level of technology for the Canadian mining industry, now and in the foreseeable future.

May 1, 2004

By R. C. A. Thurston

AT A FATIGUE SESSION organised by the A.S.T.M. in 1949, R. E. Peterson presented a brief introductory paper ( 1) in which lie referred to a discussion on the fatigue of metals which took place in England in 1849, and then proceeded to review some of the subsequent researches concerning the mechanism of fatigue. In the course of the review, he discussed metallograpl1ic studies with single crystals and polycrystalline materials, studies with X-ray methods, and the application of the electron microscope. During that hundred-year period considerable progress was made toward a better under-standing of the nature of fatigue, although it is probable that even greater attention was directed to the more practical aspects of the problem, such as the effects of notches, temperature, corrosion, surface treatment, residual stresses, and so on. Since then there has been an appreciable acceleration in the tempo of the fundamental work, partly influenced by the rapid development of the theory of dislocations, with the result that our knowledge of the mechanism of slip, the initiation of fatigue cracks, and their subsequent propagation, has still further advanced, although it is by no means complete as yet. The present paper is an attempt to out-line the more recent developments in these basic studies, to correlate them when possible, and to draw attention to those directions in which research might profitably be pursued.

Jan 1, 1957

By H. C. L. Reemeyer

One of the fundamental trade-offs for copper concentrators is between grinding circuit product size and copper recovery. The capital and operating cost savings and throughput increases for a coarser grind should be evaluated against potential recovery reductions. Other benefits of coarser grinds, such as GHG emissions reductions and favourable effects on tailings and water management should also be considered. This paper assesses the formation of laboratory and pilot test programs, design of process flowsheets, equipment selection, and evaluation methods to determine the most appropriate and economical grind size for a given deposit. The paper will include an evaluation of case studies. INTRODUCTION The majority of the world’s mined copper comes from sulphide deposits, which are mostly processed using crushing, grinding, flotation and dewatering flowsheets to produce copper-bearing concentrates for smelting. Ores must be ground to a sufficiently fine size to achieve an acceptable level of liberation to allow both high recovery of copper and valuable by-product minerals while efficiently rejecting gangue to tailings. Therefore, a key design parameter in process plant design is the grind size of the flotation feed. Copper concentrators use a variety of grind size targets that depend on various factors, including ore mineralogy and the grain sizes of valuable and gangue minerals; the sensitivity of valuable mineral recoveries in the rougher flotation stages to grind size, ore hardness; electricity costs; and mining vs. processing throughput constraints. Typically, copper and by-product recovery increase as grind size is reduced, which can improve revenue, but finer grinds increase power and grinding media operating costs and may have implications for tailings management. This paper explores the trade-offs that should be assessed in determining the optimum grind size, and to answer the question if coarser grinds are worthwhile. METALLURGICAL AND FLOWSHEET FACTORS Recovery-by-size behaviour of sulphide-bearing particles In base metals sulphide flotation, it is typical that flotation recoveries vary by particle size. Metal sulphide particles rendered hydrophobic by collector in intermediate size ranges (e.g. 10 to 100 um) usually show very high recoveries, often approaching 100%. Recovery usually falls away in finer size fractions (<10 um) as fine particles have little inertia and can move around bubbles without colliding and attaching to them. Coarser particles (>100 um) are susceptible to particle-bubble detachment and dropback (Jameson, 2019).

Jan 1, 2019

By Robert L. Tremblay

Dans le but de voir si une région comme la Gaspésie, qui a subi la derniere glaciation , se prête avantageusement à la méthode de prospection alluvionnaire, environ 800 concentrés de minéraux lourds furent prélevés dans les districts électoraux de Matane et de Gaspé-Nord. Les différentes phases minérales présentes dans les concentrés ont été examinées à la loupe binoculaire. Afin de mieux valoriser ce type d&apos;inforrnat ion, nous avons été arnenés à expérimenter et à mettre en oeuvre des techniques multivariables adaptées au traltement d&apos;une information semi-quantitative en utilisant le principe d&apos;un codage logique préalable. La structuration des résultats de la Gaspésie a conduit à l&apos;élaboration de cartes de synthèse qui constituent un support nécessaire à l&apos;interprétatlon des répartitions plus ponctuelles des minéraux "utiles" sur le plan de la recherche minière.

Jan 1, 1978

By G. S. Hume

THE discovery of natural gas with naphtha in 1924 in the Upper Palaeozoic limestone of Turner Valley, 35 miles southwest of Calgary, has led to continuous developments in this field. Drilling undertaken soon after this discovery demonstrated that the anticlinal structure was in reality a major drag-fold cut off on the east side by a westerly inclined fault of large displacement. The faulted edge of the .limestone at depth determines the eastern limits of the field, which between 1924 and 1936 was shown to have a gas area 14 miles long by about 1 mile wide. Since the strata dip westerly, away from the axis of the fold, drilling becomes progressively deeper to the west and, with the advent of deeper drilling, crude oil was discovered in 1936 on the west flank of the structure but in the same porous reservoir rocks as the gas on the crest and upper parts of the fold. Since 1936, drilling has been undertaken wholly for the production of crude-oil and at present two producing areas have been found within the Turner Valley structure. The larger of these, at the south end of the field, in the vicinity of Highwood river, has a length of about 4 3/4 miles and a proved width of one mile, whereas the smaller, in the north end of the field, south of the north fork of Sheep river, has only a few producing wells.

Jan 1, 1939

By Owen Matthews

THE property of Cochenour Willans Gold Mines, Limited, is in Dome township, Red Lake area, northwestern Ontario, a hundred miles north of Kenora and close to the Manitoba border. &apos;Planes of Canadian Pacific Air Lines, Limited, serve the district daily, except Sundays, from Kenora, Ontario, and Lac du Bonnet, Manitoba, passengers being trans-ported from Winnipeg to Lac du Bonnet by car. Freight is handled by the Patricia Transportation Company. It is brought in from Hudson, Ontario, on the Canadian National railway, in summer by water and in winter by tractor trains over the frozen lakes. The first staking on the property was done during the &apos;rush&apos; of 1926 and 1927 by William M. Cochenour, and on April 30th, 1928, a syndicate was formed, taking in claims of W. M. Cochenour and Dan Willans and H. G. Young. Surface trenching was carried on almost continuously until 1934. In October, 1932, Ventures Limited took an option on the property, and in December of that year they carried out an extensive diamond drilling programme, but considering the results did not justify further work, they relinquished the option. In July, 1934, further surface work was carried out under the supervision of W. P. Mackle and, on the strength of his report, Noah Timmins Incorporated took an option on the property and agreed to make an initial expenditure of $100,000 on development work. This was carried out under the direction of Hollinger Consolidated Gold Mines and included the sinking of a shaft to a depth of 165 feet, establishment of a level at the 150-foot horizon, and some 1,900 lineal feet of drifting and cross-cutting. The results obtained from this work were not considered of sufficient promise and the option was terminated in August, 1935. Mr. Cochenour then approached Alex Mackenzie and associates, and the present Company, Cochenour Willans Gold Mines, Limited, was organized on April 9th, 1936, and sufficient money was raised to continue operations. Under the direction of W. P. Mackle, the shaft was deepened and a second level was established at the 275-foot horizon; but, due to several adverse reports by outside engineers, it was found impossible to raise sufficient money to carry on the work and operations were suspended in December, 1937. In January, 1939, an agreement was entered into with Gold Eagle Gold Mines for the milling in their plant of some Cochenour ore. A total of 4,959 tons was treated, and the results were so encouraging that further finances were raised by C. A. Gentles & Company, of Toronto. Following further development in the mine, it was decided to erect a mill. Construction was started on September 1st and the mill was turned over on November 29th. The first gold brick was poured on December 23rd.

Jan 1, 1942

By A. M. Bell

General Summary THIS paper attempts to describe in a preliminary and general manner the nature of certain copper discoveries now being developed by Gaspe Copper Mines, Limited, in Holland township, in the interior of the Gaspe peninsula. Some copper mineralization appears to have been known here at the time of the earliest French explorations, was rediscovered in 1921, and has been under intermittent development by Noranda Mines since 1938. In the last two years discoveries have enhanced the picture so that the deposit now promises to develop into one of the important Canadian copper producers. As ideas are constantly changing with continuing development, any picture given now is very partial and tentative and must be subject to future revision. The nature of these copper occurrences differs from others known in eastern America. In many respects they have unique features but they are most closely akin to some copper deposits found away from the intrusive rocks in the porphyry copper districts of the western United States. The most important orebodies are replacement deposits in a limestone horizon in which the ore gangue is converted to skarn. These lie at considerable distances from any known intrusive but seem to have been derived from a buried stock of granite that intrudes the sedimentary rocks of Lower Devonian age. This intrusive has produced alteration effects in the overlying rocks that may afford a key to locating other ore areas in the Peninsula.

Jan 1, 1951

By John Crusius

? 3-year research program overview ? initial results- MainZone pit Waterline pit ? questions raised ? increasingly common in western N. America ? frequently low-pH waters with elevated concentrations of many metals ? water quality controls poorly understood ? some in U.S. are Superfund sites

May 1, 2002

By D. M. Maijer, S. M. Mohseni, A. B. Phillion

The microstructure evolution kinetics of aluminum alloy B206 during artificial aging has been investigated using non-isothermal calorimetry. A combination of differential-scanning calorimetry (DSC) and tensile tests have been utilized to develop an Avrami model to predict the precipitation kinetics as a function of the thermal processing parameters. The Avrami coefficients, found based on a Kissinger analysis, compare well against those reported in the literature for aluminum-copper alloys. The rapid precipitation kinetics predicted by the Avrami model at temperatures higher than 200°C were assessed through a qualitative comparison against hardness measurement results. In contrast to the continuous hardening observed at 150°C, the material softens with continuing heat treatment at 250°C resulting in an overaged state. This can be attributed to the rapid precipitation kinetics at this temperature, leading to the termination of the precipitation-hardening effects at early stages of artificial aging.

Jan 1, 2015

By Paul Toor

The operation of SAG mills is variable over time due to their continually changing liner shape, mass and subsequent load motion. However, this tends to be poorly accommodated in liner design and mill control, with only limited compensation made for this influence, usually in the first few weeks after a new liner is installed. With ever-increasing ore competency, increasing energy costs and decreasing ore grades, simplified design and operational approaches that compromise the achievable mill efficiency are no longer adequate. This paper presents a methodology that has been developed to measure and account for the changes in mill performance as the liner wears. This involves monitoring all liner profiles ? in other words the three-dimensional liner shape - over the life of the liner, then conducting controlled surveys at different stages of the liner wear life, and correlating the mill performance to the liner profiles. The measured liner mass is modelled to provide an ongoing meaningful load mass measure that excludes the liner mass.

Jan 1, 2012

By M. Choy, A. Kadiayi, E. Magdzinski

"Design of engineering controls to limit occupational noise exposure rely on accurate calculation inputs. Sound in mines can carry considerable distances. Mine ventilation engineers rely on noise propagation calculations to estimate silencer performance criteria for key mine fan installations that are often in proximity to occupied areas of a mine and can remain in service for decades. The blasted and rockbolted walls of hard rock mining tunnels have unique acoustical properties. Underground testing in an operating metal mine in Sudbury, Canada was performed and results processed to characterize noise propagation in mines, with the goal of improving the accuracy of noise calculations.INTRODUCTIONAs mine operators continue to improve and promote workplace safety, addressing noise at fixed infrastructure locations is observed as increasingly common. Underground fans are important to consider in this context, as they are typically loud, in proximity to occupied and sensitive workplaces, and operate nearly continuously. Predicting noise propagation from ventilation fans within underground mines has long been a challenge, with few available resources documenting acoustical properties as calculation inputs. Other factors in addition to rock face absorption properties include tunnel geometry and distance from the fan, which play critical roles in characterizing the noise level at any given point away from the fan. By understanding and establishing methods to better predict noise dissipation along underground mining tunnels, engineers can design noise controls with a greater degree of precision and confidence to effectively protect workers from over exposure to noise.This paper investigates classical methods of predicting reverberant room and direct field noise propagation. These prediction methods are then compared to noise measurements taken within the Fraser Mine of Glencore’s Sudbury Integrated Nickel Operations (Sudbury INO) Measurements were taken at a depth of ~881 m (2,889 ft), along an ~300 m (984 ft) long blasted hard rock mining tunnel. The noise along the mine tunnel resulted from the intakes of two 900 kW (1,200 hp) ventilation fans with a combined exhaust capacity of 300 m3/s (630,000 cfm)."

Jan 1, 2019

By G. G. Bowser

Introduction Flame shots are of very infrequent occurrence in the coal mines of Nova Scotia. Probably not more than one is recorded in three months. Many shot-firers have never experienced one, and many never will. As a consequence, although all such occurrences are very carefully investigated, information concerning the cause of flame shots is somewhat meagre. In the course of the years, however, something has been learned of the practices and conditions that are responsible for them. During the past ten? years, over seventeen million shots were fired in the coal mines of Nova Scotia and only fifty-two faulty shots were reported or investigated during that time. In thirty-nine of these, flames were reported; in five, sparks only; and in eight, smoke only. In eight of these occurrences, unburned explosive was found after firing. In one of these eight, flame was seen in the back part of the hole, and an accompanying hissing sound pointed to burning explosive. In four of them, there was no evidence that gas was not ignited. All samples of explosives from these faulty shots which were submitted for analysis were found to be normal, except two, in 1937, which contained excessive moisture. These two samples were from two following shots in the same room on the same day. The initial cause of trouble with all eight shots was one or several of the following: explosives in poor condition, separation of cartridges, incorrect priming, shot hole in poor condition or not properly cleaned. In the case of sixteen or seventeen of the thirty-nine shots which flamed, data are insufficient for conclusions to be drawn as to the cause of the flame.

Jan 1, 1947

By Daniel J. Corkery

Mines in Canada and the United States are subject to regulations limiting ammonia, nitrate and nitrite levels in mine effluents released into the environment. The primary source of these nitrogen compounds is typically explosive used in blasting operations, as ammonium nitrate (AN) remains a significant component of most explosives used in the mining industry. The amount of AN entering a local water drainage system is related to site conditions, explosives used, explosive handling and blast efficiency. Mining operators acknowledge AN loss to mine water from blasting operations. However, the mechanisms by which ammonia, nitrite and nitrate are entering the water drainage system, or the relative contribution of specific mechanisms, may not necessarily be assessed or monitored adequately. Characterization of these mechanisms, through systematic investigations, allows a mining operation to focus its efforts on reducing AN loss. This paper outlines a strategy for investigating the mechanisms through which AN enters the mine water drainage system and methods to mitigate this loss. This strategy includes collection and analysis of data to identify and quantify the AN loss mechanisms, design and implementation of tests to mitigate this loss, and assessment of the results. Such investigations are not intended to be a separate one-time project, but part of a long-term process of continual feedback and optimization that is related to the collection and reporting of AN levels for regulatory purposes. The implementation of the strategy must be tailored to each mine?s requirements and existing conditions.

Oct 1, 2010