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Gaby Copper Mining?s Gabriela Mistral property is located in the Antofagasta region of northern Chile, at an altitude of 2,660 m (8,727 ft) above sea level. The reserve contains an estimated 562 Mt (620 million st) of oxide ore with an average grade of 0.41 percent total copper. The mine went into production in 2008. Gaby Copper faced the problem of having no reliable way to measure the solids level. This is a challenge that exists throughout the mining industry, where dust in the air and accumulation of solids on a sensor make accurate measurements difficult in areas such as transfer chutes, the rock box underneath crushers, silos and anywhere else that information is needed on the level of solids. The next-generation technology in the Sitrans LR560 radar from Siemens addresses this challenge. With a frequency of 78 GHz ? higher than previous generations of radar ? it provides a more robust signal for measuring in areas where there are high levels of dust accumulation. The Sitrans LR560 provides a signal beam angle of four degrees, significantly narrower than any other product on the market can offer.

Jan 1, 2014

By William E. Cobb

15.1 INTRODUCTION The mine development process, as discussed in Chapter 2, is a series of data gathering and analysis steps. As the mine development process proceeds, information about the geology, mineability, and metallurgy of a particular deposit is continually generated, along with environmental information regarding project permitting status. As data are obtained, checkpoint evaluations are typically conducted to determine the economic viability of the particular deposit. Although the project evaluation process was discussed at length in Chapter 2, a brief review of the process is presented here to "set the stage" for the discussion on economic analysis of heap leach projects. Figure 15.1 (MacKenzie, 1980) presents an overview of the sequential process of mine development. Once the deposit is discovered or acquired, an initial delineation program can be undertaken to expand the project's geologic, mining, and metallurgical data base. At the end of this initial program, the direction of the project is evaluated. The company can either abandon the project, postpone it, develop and mine it, or gather additional data in hopes of improving the project's economic viability. If the company continues gathering data, then another decision point and evaluation will be required. This process may continue until the company either decides to postpone the project or develop and mine it. A project may be postponed indefinitely, typically in hopes of improved metals prices. Certain holding costs, such as land or royalty payments, may be associated with postponement. In general, once a company goes through two evaluations, the project is less likely to be abandoned. For this discussion, it is assumed that the company will undertake initial, second, and third delineation programs to gather sufficient geologic, mining, metallurgical , and environmental data to justify a positive production decision from the second or third economic evaluation. The objectives of the first delineation program will be to confirm and expand upon the available information about the deposit. During the second delineation program, development funds should be directed toward identifying the critical project items (i .e., ore reserves, mineralogy, mineable grade, metallurgical recovery, etc.) that must be resolved before making the production decision. This second economic evaluation can be used to determine which metallurgical concept will be applied to the project: heap leach or a traditional agitation-type leach plant. If the proper work has solved key project concerns in the second program, a production decision may be made from that evaluation.

Jan 1, 1988

By G. R. Laurer, J. W. Neton, C. Pomroy, N. Cohen, M. Eisenbud

INTRODUCTION In uranium miners, a causal relationship between exposure of the lung to high levels of alpha radiation and the consequential induction of bronchial carcinoma is now well-established (Wagoner, et al., 1965). Quantitation of this cause-effect association presents considerable difficulty, however, as the result of various confounding factors such as the contributing effects of smoking and/or arsenic exposure (Archer, Gillam, and Wagoner, 1976), normal metabolic variability and, perhaps most important of all, the absence of accurate radon/radon daughter exposure data. Estimates of cumulative lung exposures suffer from inaccuracy due to critical factors such as 1) unknown ventilation rates; 2) difficulties in obtaining representative mine air samples; 3) the variable character and magnitudes of the exposure sources; and 4) specific differences in metabolism and job histories that exist among miners. It was with considerable enthusiasm, therefore, that investigators readily embraced the idea of using skeletal burdens of the relatively longlived descendants of radon and its short-lived daughters, i.e., 210 Pb and 210Po (Archer, et al., 1968), to provide a measure of cumulative past exposure wherein the body acts as an integrating dosimeter. Early studies considered excretion rates of 210Pb and 210Po in urine, blood and hair (Sultzer and Hursh, 1954; Black, et al., 1968; Jaworowski, 1965; Bell and Gilliland, 1964) as well as their concentrations in bone samples, if and when they became available (Blanchard, Archer, and Saccomanno, 1969). These methods were ultimately complemented by in vivo, whole-body counting techniques using low background, NaI-Csl(T1) detectors (Eisenbud, et al., 1969). By this latter method, it would be possible to measure the skeletal burden of 210Pb directly, thereby avoiding the many difficulties associated with the relation between nuclide excretion rates and body burden. The rationale was simple; by knowing the skeletal burden of 210Pb it should be possible, by the judicious use of an applicable metabolic model, to estimate the cumulative lung exposure to alpha-emitting radon daughters (Fig. 1). Various models that were consequently constructed, however (Fisher, 1969), all suffered from the same limitation, i.e., the assumption that the source of 210 Pb in the skeleton and the source of lung exposure to the short-lived radon daughters were simply related and, if not, were at [ ] least not too variable (Raabe, 1970). By now, the difficulty with this assumption has been recognized and more sophisticated modeling techniques have been attempted which presumably present a more realistic picture of exposure conditions (Holtzman and Rundo, 1981). There is, nevertheless, the pessimistic view that due to the variety and variability (in time as well as in character) of sources that may exist for the origin of 210Pb in bone, it may [never] be possible to estimate past lung exposures accurately by an indirect, predictive model. For example, the origin of 210 Pb in the skeleton may include such sources as: 1) the decay of short-lived 222Rn daughters, inhaled and ingested; 2) the decay of 222Rn dissolved in body fluids and tissues; 3) directly from 210 Pb present in air, inhaled and ingested; and 4) 210Pb from non-occupational sources, e.g., food, water, smoking and endogenous 226Ra. The contribution of each of these sources may vary depending upon specific site conditions such as ventilation and mining operation. On the other hand, empirical evidence seems to indicate a trend reflecting the simplest of direct

Jan 1, 1981

By K. Kavouridis

Coal is broadly recognized as sure, competitive, diversified, not vulnerable and predictable in price energy resource. In power generation coal is playing a dominant role in the EU-27 with 25% of installed capacity and almost one third of the power generation. The role played by the domestic resources and especially by coal are increasingly becoming the focus of the EU energy strategy. There is a strong pressure for the decarbonization of the energy mix. The Emission Trading system (ETs) can have an impact on the shift to lower carbon-intensity fuels. The impact of ETs on coal can be important, because it is very short sighted and only defines the period up to 2008-2012. The ETs CO2 regime must ensure that investment in coal-fired plants in the long term are supported. EU Research Institutes and Coal Industry identified an important CO2 reduction potential by improving the efficiency of the conversion of solid fuels into electricity. Highly efficient clean coal technologies can contribute to reasonable costs and challenge the issue of climate change. It must be pointed out that the EU Energy policy should now concentrate on the necessity to effectively support demonstration projects and to create the legal framework for the integrated approach of efficiency enhancement and CCS. It is not a right approach to implement CCS before the technology is demonstrated and before it is clear that it will be commercially viable.

Jan 1, 2007

By A. F. Edwards

The Main Pass sulphur and oil deposit is located at Main Pass Block 299 in the Gulf of Mexico, 30 miles east of Venice, Louisiana, in 210 feet of water. The deposit was discovered by Freeport-McMoRan and its joint venture partners, IMC Fertilizer and Homestake Mining, in late 1988-early 1989. The sulphur deposit contains 67 million long tons of recoverable sulphur. The sulphur occurs in bio-epigenetic limestone replacing anhydrite caprock on top of a salt diapir. Recoverable reserves of 39.4 million barrels of oil and 9.1 billion cubic feet of gas are also contained in the limestone caprock and in supracap sandstone stringers.

Jan 1, 1992

By John J. Mancini

Elastomeric liner products have been used for over two decades in a wide variety of uses including pond liners, hazardous waste barriers, dam face rehabilitation and mining applications. Asphalt blended with polymers is enjoying renewed interest in the engineering community because of its durability, high yield attributes, fewer CQA steps due to seamless installation, and ease of installation and repair. As in other lining technologies, advancements in polymer chemistry and improvements in installation techniques have had dramatic impact on the quality of fluid-applied asphalt (FAA) membranes. Membrane 6, man­ufactured by Deery Oil, Inc. for over 16 years is a hot-applied polymer modified asphalt membrane that can be applied to a variety of substrates in a reinforced configuration or installed directly on an asphalt surface. By blending thermoplastic polymers with asphalt, very favorable stress/strain characteristics can be achieved (Chambers, 1980). Typically the membrane will yield under rel­atively low stress and also exhibit high elongation capability. In service applications where puncture resistance is a concern, fluid applied asphalt materials have the flexibility and com­pressive strength under heavy loading that leach pad designers may find attractive. Additional security is achieved if long term service life is important as in the case of radioactive waste con­tainment. The Department of Energy selected Membrane 6 over seamed liners for a surface barrier that must isolate and contain radioactive waste for 1000 years. Asphalt has a long history of use as a water-stop material and it is believed that this natural construction material combined with SBS polymers will per-form for a millennium. (Freeman, 1994) The process of installing Membrane 6 varies according to job size and the type of surface to be protected. Lining applica­tions on compacted substrates require the membrane to be applied to a scrim cloth (fig 1). Some early pioneers in FAA technology neglected this step and therefore never achieved per­formance levels that satisfied regulatory guidelines. The scrim provides a cohesive surface that promotes membrane flow while achieving high impermeability (2Xl0 '11).

Jan 1, 1996

By William H. Meadows

This information describes the ventilating and methane gas testing procedures utilized during the raising of a mine shaft using a Robbins 81-R drill. An overview of the raise boring process is presented to illustrate the ventilating and gas testing procedures. A mine shaft project, 4.88 m (16 ft) in diameter and approximately 457.2 m (1500 ft) in length, will be the focal point of the presentation, with reference to similar projects for additional comments on variations in procedure.

Jan 1, 1980

By Kevin Stuffle, James E. Sharp, Sean Premeau

Two process enhancements for the biological oxidative pretreatment of sulfidic gold ore for subsequent treatment with cyanide are discussed. These are the use of a high areal density ring and pin packing (BioBalls™) as substrate, and the use of a novel biological ferric generator. The BioBall™ packing when coated with concentrates for heap leach processing offers higher areal densities, while leaving more open volume for fluid flow than more commonly used substrates such as aggregate. An oxidation rate study was performed on crushed auriferous arsenopyrite whole ore to demonstrate the benefits of using the packing. The auriferous arsenopyrite grading 2.9% Fe and .212 OPT gold was 50 percent oxidized in 24 days. The biological ferric generator is a passive air-side trickle bed reactor that efficiently converts ferrous to ferric in a process stream. Conversion rates of .8g/L h ferrous to ferric are routinely obtained. Although the biologically generated ferric solutions have not yet been tested on gold ores or concentrates, prior work has demonstrated that the high ferric solutions which will result in rapid oxidation of sulfidic gold ores or concentrates.

Jan 1, 1997

By James B. Loftis

The importance of increasing the world's mineral production to help solve our food and energy problems has been widely discussed. Improved surface mining methods will be needed to meet these needs. This paper reviews the modern horizontal drilling and blasting methods which can increase the productivity and lower the costs of I surface mining. A substantial decrease in the number of blast holes required, total footage of blast hole required and amount of explosive used has been realized by many mining companies using this method. Applications of this method are presently in large coal surface mines. However, similar gains are possible and probable in open pit mining of copper and iron.

Jan 1, 1975

By William W. Wellborn

Abrasives are substances both natural and synthetic that are used to grind, polish, abrade, scour, clean, or otherwise remove solid material usually by rubbing action (as in a grinding wheel), but also by impact (pressure blasting). Facts about the discovery, early use, adaptation, and development of abrasives prior to the 20th century are few. From the sparse, earliest information that is available, it would appear that the science of abrasives began when, to fashion his tools, man began to select certain kinds of rocks in preference to others because of their peculiar properties. There is evidence that stones were sawed by some sort of grinding machine as early as 4000 BC in Egypt. The real expansion of abrasives use coincided with the beginning of metallurgy in the Middle East around 2000 BC. The earliest confirmed use of abrasives for grinding metal comes from a steel dagger found along with a sharpening stone which was dated at about 1500 BC. Natural and manufactured abrasive substances play an important role in fashioning and finishing numerous products with a wide variety of end-use applications. The mining and preparation of crude, natural abrasives for their markets and the manufacture of synthetic and other abrasive materials contribute significantly to the US economy (Table 1). In addition, just as sawing to specific dimensions enhanced the value of the Egyptian stone, the use of abrasives in fabrication of modem products, and the addition of abrasives to others, add value. GENERAL CONSIDERATIONS The most important physical properties of materials that qualify as abrasives are hardness, toughness (or rigidity), grain shape and size, character of fracture (or cleavage), and purity (or uniformity). To fabricate bonded abrasive products such as grinding wheels, additional considerations include stability under high heat and bonding characteristics of grain surfaces. The economic factors of cost and availability are always important. No one singular property is paramount for any use. For some applications extreme hardness and toughness are needed, as in diamonds for drill bits. For other uses, factors of greatest importance are hardness and ability to break down slowly and, in the process, develop fresh cutting edges when grains become worn. In garnet sandpaper, for example, highly cleavable, friable, or extremely tough grains are not desirable. For other uses, extreme hardness may be objectionable. Abrasives for dentifrices and for glass-cleaning soaps are cases in point. For the most efficient uses in more critical applications, different types of abrasives are rarely completely interchangeable. While crushed quartz and garnet are both used in sandpaper, the two abrasives are not at all interchangeable in their applications. In the final analysis, the choice of a high-grade abrasive depends upon the quality and quantity of work performed by the abrasive per unit of cost. Initial cost of an artificial abrasive may be much greater than that of a natural abrasive, but the artificial mineral may do so much better work and do it so much faster that the ultimate cost is less. It is for this reason that artificial abrasives have largely replaced natural abrasives.

Jan 1, 1994

By M. Leroux, S. R. Rao, J. Kim, V. Gervais, J. A. Finch, G. Labonté, N. Macminn, M. Ounpuu

Collectorless flotation of sulphide minerals from Lyon Lake ore (Mattabi Mines Ltd.) has been studied both in the laboratory and plant. Among the four major minerals chalcopyrite showed the greatest response to collectorless flotation, followed by galena. Flotation of sphalerite and pyrite was minimal. Collectorless flotation was influenced by pulp potential and pH. Experiments using different gas compositions showed collectorless flotation was promoted when the pulp potentials were greater than about 0 mV (SCE). The study of the effect of depressants showed that SO2 at pH < 8.0 depresses both galena and chalcopyrite but at pH 9.5 flotation of chalcopyrite recovers. Use of NaCN preferentially depressed chalcopyrite compared to galena. Preliminary results from plant tests at Mattabi Mines Ltd. confirm that collectorless flotation occurs and that it is preferential for chalcopyrite and to a lesser extent galena. Practical implications of collectorless flotation in plant practice are discussed. A critical factor will be silver recovery.

Jan 1, 1989

By Wendell H. Nielson

Flotation processes contain disturbances which make material balance closures difficult to achieve. Lack of closure also arises from instrument errors. A portion of these problems can be overcome by proper equipment selection; the primary measurement installation and methods of initial data filtering are discussed below. The problem of data adjustment has been considered before (2). The technique described here is essentially that of Ripps (2). The technique was expanded to include linearization of non-linear material balance equations. An additional large error detection portion was also added to Ripp&apos;s formulation. Ripp&apos;s technique is based on a Lagrange-Multiplier optimization method. The Lagrange-Multiplier technique is generally applied when there are equality constraints on the variables. Steady-state material balance equations fit in this category. The basic Lagrange-Multiplier method is described. It is followed by a description of the modified material balance data adjustment technique. An example is presented to illustrate the use of this method.

Jan 1, 1970

By K. S. Venkataraman

The physical properties of clay-water systems depend on the complicated system of forces between the clay particles themselves, and between the clay particles and the ions in the liquid phase. The kind and distribution of ions in, on, and between the clay particles and the size and the shape of the particles are the basic factors determining the macroscopic behavior of clay-water systems. Understanding the system requires a knowledge of the nature of the clay particles, their size, structure, composition, and surface properties, and of the manner in which they interact with ions [and molecules] in the surrounding liquid [or other medium]. The validity of Professor Brindley&apos;s words (Brindley, 1958), written three decades ago in the context of making pottery, whitewares, and electrical porcelains, transcends time, and the basic message is perhaps all the more important in the considerably expanded use of ceramics for structural, thermal, tribological, electronic, and other applications. Silicon carbide, silicon nitride, and sialons have been studied in the last two decades for high- temperature structural and tribological applications, particularly for using in internal combustion engines. Titanates, zirconates and niobates of barium, strontium and lead, have high dielectric constants, and are extensively used in the formulations for making capacitors. Hexagonal ferrites (molecular formula MO.6Fe2O3) are in use for making permanent magnets for fabricating miniature motors, and for assembling loud speakers, particle accelerators etc. Cubic ferrites such as magnesium-zinc ferrite and nickel-zinc ferrite are used as transformer cores, and for other high-frequency applications. In this context, Richerson&apos;s recent book (Richerson, 1984) on the general scope of traditional and technical ceramics is a good starting point for an overview of contemporary ceramics technology. Glasses are a whole class of amorphous materials used widely as sintering aids, and for making glass-bonded ceramics and glass-ceramic composites. Composites are yet another burgeoning field where two or more particulate components are used for improving the performance of ceramics. For all these applications, the inorganic starting materials are almost always submicron and near-micron powders. Understanding the powders&apos; physicochemical properties, and their surface chemical interactions with the surrounding liquid/gaseous medium is-necessary for making reliable ceramic parts at competitive prices. Even though ceramics science and engineering has attained its separate identity in universities and the industry, ceramists themselves would concede that ceramics science is a cross-disciplinary field, having incorporated and assimilated within itself many principles from several apparently disjointed disciplines. Principles of material science, graduate-level physics and chemistry, polymer science, surface and colloid chemistry, transport phenomena, particle technology, unit operations commonly used in chemical engineering and mineral processing, and statistics and applied mathematics are integral part of any ceramics curriculum in universities. Added to this is the fact that all bench-scale successes in making ceramic parts are to be scaled-up for larger throughput operations. Understanding and applying process engineering principles of comminution, classification, drying, calcination, etc. then becomes essential. CERAMIC FORMING: Despite the diversity of the materials and processes, conceptually, the steps involved in making ceramic parts have remained the same over several decades: The different components for making the pan (usually one or more powders plus other forming and sintering additives) are proportioned and mixed thoroughly, and the well-mixed formulations are consolidated into desirable shapes known as "green bodies." Usually binders such as wax, clay, organic polymers and surfactants, whether dispersed or dissolved in a suitable liquid are used during mixing the batch for giving strength for the green bodies. In the dried green state, the inorganic powders typically occupy only 55 to 60% of the bulk volume of the body, depending on the particle size distributions of the powders and the forming history, with mostly inter- particle voids accounting for the rest of the void volume. SINTERING: The formed bodies are then fired in high- temperatures kilns/furnaces during which the parts are exposed to a predetermined temperature profile, and "soaked" for a certain duration at the final high temperatures, typically between 1200 K and 1900 K, and then cooled to room temperature. The gaseous atmosphere in the furnace is controlled (oxidizing, reducing, or inert) when necessary. During the initial stages of firing, volatile liquids evaporate, and during the intermediate temperatures between 400 and 600 K, the the organic polymeric additives pyrolize and oxidize into water vapor, CO, C02, and other gases. At still high temperature, the glasses, when present, soften, and simultaneously, the ceramic particles rearrange into a network of grains with definite grain boundaries so as to reduce the total interfacial free

Jan 1, 1990

By R. K. Amankwah, E. K. Asiam

Changes in the thermal-oxidation behavior and other properties of gold-bearing waste activated carbon when milled in both a ball mill and a vibratory mill were investigated. It was found that significant changes occurred in the oxidation temperature of the vibration-milled waste carbon as a result of increases in surface area and mechano-chemical activation. The mechano-chemical action brought about modifications in the crystal structure of the waste carbon. As a result, the vibration-milled sample was completely oxidized at a temperature of 450°C. Thus, the study established that vibration milling is a better way of lowering the temperature of oxidation of the waste carbon. Furthermore, the gold was found to be concentrated in the ash and, when leached with cyanide for 20 hrs, the gold recoveries from a sample having a head grade of 2 kg/t was 99.5% for the vibration-milled sample and 82% for the ball-milled sample. The lower gold recovery for the ball-milled sample was attributed to sintering of the ash, which was caused by the higher temperature required for its oxidation.

Jan 1, 1997

By DING TANG, JINGHE CHEN, Shuiping Zhong, CHEN KUANG

The Zijinshan gold-copper mine, located in Shanghang County, China, is a porphyry-type, low-grade ore deposit with a geological profile of upper gold and lower copper. Despite its low-grade nature, it has become one of the largest in production scale and most profitable nonferrous metal mines in China, which can be attributed to the successful application of hydrometallurgy as well as proper engineering design. A large-scale, open-air cyanide heap leach has been successfully implemented to recover gold under the humid and rainy weather conditions of southern China. Furthermore, according to the gold ore characteristics, a combination of gravity separation, carbon-in-leach and heap leaching processes was developed to improve gold recovery. In terms of copper extraction, copper ore of a grade higher than 0.25 percent is fed to the flotation plants to produce copper concentrate (gold is also enriched here), while copper ore of a grade lower than 0.25 percent undergoes heap bioleaching followed by solvent extraction and electrowinning to produce cathode copper. Additionally, a unique bioleaching system has been established at the Zijinshan Mine: low operating pH (0.8~1.0), high concentration of total soluble iron (~50 g/L), high temperatures (45~60 °C) and low activity of microorganism (~104/mL) in the pregnant leach solution (PLS). This review paper summarizes the practical experience acquired in developing the Zijinshan gold-copper mine and could be of use in other gold and/or copper plants.

By L. Shwydiuk, A. Chrzanowski, W. Newcomen, G. Bastin, R. Wilkins

Automated monitoring of steep embankments allows the early detection of instability and can be used to avoid or mitigate possible slope failures. A system that uses multiple and different types of sensors has been created and successfully tested at the Highland Valley Copper mine in British Columbia. The system uses robotic total stations (RTSs) as the primary measurement sensor, with surveys repeated at predefined intervals selected to optimize operational efficiency. A methodology has been developed to improve the system’s accuracy and reliability by reducing the effects of systematic errors created by atmospheric refraction and unstable instrument and reference point positions. The inclusion of GPS sensors to monitor the RTS positions creates additional operational flexibility and maintains system integrity when insufficient reference stations are available.

Jan 1, 2003

By James C. Cobb

Middle Pennsylvanian (Desmoinesian) coals of certain areas of the Illinois and Forest City Basins contain epigenetic sphalerite and associated minerals in veins, clastic dikes, cleat, and other small-scale structural features. The presence of sphalerite in these coals records information about the geology of coals and coal basins, and represents a potential source for zinc as a byproduct of coal production. Origin of Sphalerite in Coal The origin of sphalerite in coal suggested by Cobb (1) involves sphalerite precipitation from zinc-bearing ?Na-Ca-Cl brines upon contact with sources of sulfur in the coal bed, e.g., pyrite, H2S, and organic sulfur. These brines were essentially at the temperature of the host coals as determined by fluid-inclusion thermometry and vitrinite-reflectance studies. The migration of these brines into coal beds may have been caused by compaction of sediments due to continued sediment loading of the coal basins. Zones of high permeability such as sandstones and the coals themselves presumably acted as conduits for the movement of the brines. The open spaces where sphalerite was deposited resulted from minor deformation associated with differential compaction and cleat formation enhanced by volume shrinkage during coalification.

Jan 1, 1982

By Slavko Ostojic, V. G. Hill

This paper reviews various bauxite classification schemes with respect to the differences in texture, composition and geological associations of the deposits. It demonstrates that a techno-economic classification, based on: a) associated rock type - lateritic versus karstic, b) content of aluminum ore minerals - gibbsite, boehmite and diaspore, and c) gangue minerals (iron oxides etc.) has a geological basis with natural cut-off points for the bauxite types identified. Thus, this scheme is seen as applicable to bauxite resources. It also provides a basis for their rational exploitation taking into consideration the long-term interests of both the bauxite producing and consuming countries. Against this background, the industrial mineral or non-metallurgical grades of bauxite are seen as localised and relatively rare occurrences. Their consumption should, therefore, be aimed toward the specific (hence more remunerative) products as indicated by the bauxite characteristics.

Jan 1, 1984

By M. K. LeBegue

Water sprays located behind the bits of cutter drums have been shown to reduce the incidence of face ignitions. This paper details the design approach to successfully incorporating water seals into a drum miner cutter head.

Jan 1, 1999

By Gilles A. Tremblay

Acidic drainage has been long recognized to be the largest environmental liability facing the Canadian mining industry and to a lesser extent the public through abandoned mines. The Mine Environment Neutral Drainage (MEND) Program was the first initiative formed in 1989 to develop scientifically-based technologies to combat acidic drainage. This 9-year volunteer program reduced the liability by several hundreds of million dollars and established Canada as the recognized leader in research and development on acidic drainage for metal mines. MEND 2000 is a three-year program that started in 1998. The key to MEND 2000 is technology transfer- providing state-of-the-art information and technology developments to users. MEND-developed technologies are being verified by long-term monitoring of large-scale field tests. Maintaining linkages with a number of foreign government and industry-driven programs is also important to the successful completion of the program. Through these efforts a further reduction of the environmental liability associated with acidic drainage will be realized.

Jan 1, 2000