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By Wm. I. Weisman

Sometimes in assessing where we are and where we are going it is informative to take a look at where we have been. Whether or not it adds to our understanding of the present, I think it may be interesting to review some of the past history of our industry. As a starting point I chose to use the famous Paley Commission Report, formally known as "The U. S. President's materials Policy Commission -Resources for Freedom."(l) The Paley Commission report said "Fluorspar is an essential raw material for the steel, aluminum, and chemical industries." Of course this statement is still true. It also said, "United States known reserves of fluorspar would be sufficient for some 15 years at present rates of consumption--about 426 000 short tons in 1960. Projected consumption for 1975, however, is several times as great, and reserves in other free countries do not appear adequate to supply United States deficiencies during the next 25 years." This simply demonstrates how even the most learned and competent people can observe all the facts avail-able to them at a given time and yet be unable to predict the future very accurately. We all know that reserves in other countries are more than adequate to supply the United States today, 25 years since the report was published. In fact, the report estimated free-world reserves at something over 36 million tonnes (40 million short tons). Contrast this with 246 million tonnes (271 million short tons) estimated as total world reserves from the section on fluorspar from Commodity Data Summaries of 1974, published by the Department of the Interior. (2) The Paley Report discusses other matters pertaining to fluorspar that are still of interest, such as improving mining methods. Furthermore, it certainly did a good forecasting job in noting that greater recycling should become possible in the aluminum industry in regard to fluorine lost in wastes and also concerning the substitution of fluorspar in the steel industry by other fluxing materials. It also suggested that non-fluorine containing propellants should be investigated as a replacement of those containing fluorine as a conservation matter. Some discussion was devoted to recovering the fluorine content of phosphate rock, which is being practiced today, but was in its infancy in 1950.

Jan 1, 1978

By Samer Sadek, Phoebe Cheng, Changmo Kwon, Myat Ohn

BART Facilities Standards (BFS) Structural Criteria is a living document that governs planning, design, and construction of all BART projects. Since its development, the document undergoes incremental changes and updates to reflect policy changes, changes in local, State, or national design codes and guidelines, advancements in engineering and technology, or based on the performance of past built infrastructure. In 2020, the BFS-Structural Criteria underwent a comprehensive update and was released with BFS version 3.2. This paper summarizes the updates to the Tunnels and Underground Structures Section of the Structural Criteria, and provides insights to the basis and logic of the requirements.

Dec 1, 2022

By Carson Rife, Michael L. Clark

INTRODUCTION Zortman Mining Inc. is a wholly owned subsidiary of Pegasus Gold Corporation of Spokane, Washington. Pegasus has been producing gold and silver from the Zortman and Landusky mines since 1979. The Zortman and Landusky mines are two distinct open pit mines located approximately 6 kilometers apart in the Little Rockies Mining District of north central Montana. The two mines use large-tonnage, low- grade heap leaching techniques to efficiently process the gold and silver ore. PROJECT DESCRIPTION The Little Rockies rise abruptly 914 metres from the surrounding plains to about 1829 metres above sea level. The topography is quite steep, making efficient leach pad construction a major challenge. The climate is semi-arid with moderate summers and occasionally severe winters. Freezing temperatures usually arrive in late October or early November, influencing the effectiveness of leaching operations. GEOLOGY AND MINERALOGY The geology of the Little Rocky Mountains consists of steeply dipping sedimentary ridges forming an elliptical dome surrounding a core of intruding syenite porphyry. Within the syenite porphyry are well fractured and mineralized shear zones where the existing reserves and open pits are located. The ore is presently divided into oxidized, mixed, and sulfide. Only the oxides and mixed zones that are of ore grade are placed on the leach pads. The syenite porphyry host rock enables effective leaching of gold and silver to depths of 61 metres, having a major impact on leach pad construction costs. MINING All mining since 1979 has been by contractor. This enabled initial mining to commence without capital investment in equipment. Through competitive negotiations, Pegasus has been able to keep contract mining costs at levels very close to what would be experienced if Pegasus had purchased equipment initially. Contracts are negotiated yearly and are based on a unit price and haul distance for ore and waste. Haul distances have ranged from as little as 457 metres to as much as 3,050 metres. At present, Pegasus is developing a 27,000,000-tonne leach pad at the Landusky project that is adjacent to the minine area. This design feature will reduce the mining cost by 20 percent over the life of the mine. In 1987, over 5,900,000 tonnes of ore and 3,200,000 tonnes of waste will be mined at the Landusky project. Through 1986, 13,763,000 tonnes of ore have been mined at a waste-to-ore strip ratio of 0.60:l at the Zortman project, and 13,005,000 tonnes of ore at a waste-to-ore strip ratio of 0.79:l have been mined at the Landusky project. Current mining reserves are 32,769,000 tonnes of ore at a waste- to-ore strip ratio of 0.59:l. Through efficiencies of large-scale heap leaching, Pegasus has been able to lower the mining cutoff from 0.34 grams per tonne gold to 0.27 grams per tonne gold. This has reduced the mining cost per tonne of ore h percent through a reduction in strip ratio of 14 percent. Beginning in 1984, all pits were designed based on computer-generated "floating cone" pits. The geologic models were developed by Pegasus staff with a series of economic models evaluated. The resulting computer-generated pits were used as a guideline in designing the mine plans, including haul roads for final calculation of tons and grade. Input to the floating cone models consisted of mining cost, processing cost, cutoff grade (0.34 grams gold per tonne), recovery (67 percent) and gold price. Due to the gold being deposited primarily on the fractures of the syenite host rock, no crushing of ore is needed prior to leaching. This characteristic of the ore is a key in being able to profitably mine and process gold ore at an average grade of 0.69 grams of gold per tonne. Strict blasting control is also a key in success of the leaching operation. A system of splitting ore and waste in blast patterns has been devised to reduce dilution. Also, drill hole spacings are varied from 3m x 3m in breccia ore to 4m x 4m in syenite ore to 5m x 5m in waste. Drill holes

Jan 1, 1987

By Liz Diaz, Tacio Ferreira

Capstone Copper’s Pinto Valley Mine faced challenges in recovering rock and ore on final walls because of geotechnical constraints that require restrictions on methods for loading blastholes adjacent to the pit boundaries to preserve wall stability. The operation had been using the same drill and blast designs for years. With changing geology, such as harder rock, as mining progressed, material was being left unmined in final walls because of poor breakage. The amount of unrecovered, unprocessed ore was estimated at approximately 380,000 tons a year generated from an average of 60 final wall blasts performed annually. The engineering team from Capstone and Dyno Nobel engaged to minimize the amount of material left on the final pit walls. This paper presents how we collected data, reviewed design standards, and found opportunities to improve ore recovery from pit final walls without increasing drilling and blasting costs. The results collected from implementing the new design on two benches showed the potential for extra revenue of approximately $3.6 million generated annually from reducing final wall unrecoverable underbreak by nearly 71% on the mine’s highwalls.

Feb 1, 2025

By V. Russel Burkhart

One of the most difficult items to justify economically on any budget is a training program. The costs can easily be identified--primarily the cost of the program and the inconvenience and cost of filling in for the men taking the training by working other personnel extra hours at overtime rates. Operating efficiency, higher productivity, increased plant availability, development of confidence, improvement in morale and less absenteeism are only a few of the benefits which far exceed the costs. A good preparation plant training program can accomplish more in 5 weeks than can be accomplished in five years of on-the-lob operation. During recent years, coal preparation plants have become more sophisticated and complex as the specification for coal used by electric utilities in their power plants have required improvements in coal quality to adhere to air quality regulations and to improve boiler performance and reliability.

Jan 1, 1981

By David A. Fawcett

An auxiliary cross-pit mining system, working in tandem with the prime excavator, is evaluated technically, operationally and economically for application in the selective removal and replacement of soils and unconsolidated ovezburden. Previous studies on cross-pit technology and applications of this technology are briefly reviewed. Stratigraphy plus pit, operating and economic parameters are assumed and applied in the evaluation and comparison of a base case dragline system with two alternatives - a dragline/scraper-dozer combination and a drag- line/cross-pit system combination. The economics of the proposed cross-pit system favour it as a viable alternative to conventional systems.

Jan 1, 1981

By J. B. Moritz

From the beginning, man has concerned himself with the task of controlling the elements and forces about him so as to provide a better and easier life. In the accomplishment of this task, he is required to utilize in the best way possible the resources which are available to him. In many cases, the available resources must bee refined before they are in a useable form. Many products in the mining industry fall into this category, as some form of refinement is generally needed to produce a saleable product. Over the years man developed more efficient ways of extracting the resources from earth through the use of electrical and mechanical devices. A reduction in manual labor, which is a by-product of increased efficiency through machines, has also been enjoyed. The combination of man's senses and new devices has also enabled man to reach a high level of control in the refinement process. Control of a process through machinery and man's senses has been termed an "art." Until recently man's senses (sight, feel) were the only method available for making measurements simply because suitable measurement devices (instruments) were not available. Even today some items cannot be measured and man's senses must be used. However, the development in our instrument laboratories tends to indicate that time will eliminate this. In recent years, control of many processes has been reduced to a science and part or all of the art eliminated. This does not imply that process art should be degraded; however, when a process is reduced to a science, uniformity of the product from day to day is attained. Decreased processing time and more efficient use of additives and raw materials are other benefits that result from control of a process when it is reduced to a science.

Jan 1, 1965

By Alvin Kaufman

Malthus, an eighteenth century economist, predicted a rather dismal future for the world. It was his contention food supplies would not be sufficient for the population of the world because the economy of a nation grew arithmetically while population increased geometrically. As a consequence, within a relatively few years mass famine would spread throughout the world. This prophecy, based on an agrarian economic situation, did not come true at least insofar as the Western World was concerned. In largo measure, the salvation of our part of the earth resulted from the growth engendered by the Industrial Revolution. Throughout much of today's world, however, the Malthusian theory seems to be coming true. The advantages and benefits of the Industrial Revolution have net reached all nations. Further, the situation has been compounded by the benefits of modern medicine. This has reduced child mortality and extended life expectancy, but placed no limitations on births in the developed countries, child mortality has declined to 2 percent and adult life expectancy has doubled, but education and general prosperity have resulted in voluntary limitations on pregnancies thus partly offsetting the increased chance of survivals Even so, the present rate of population increase in Europe is approximately 6 percent per decade, and somewhat higher in the U.S., Japan, and other developed countries. The world as a whole, however, is expected to double its population by the year 2000, This would imply a rate of increase in the less developed countries approximately four times that in Europe.

Jan 1, 1966

By J. Ke

Traditional geostatistical methods have been used in ore reserve estimation for decades. Neural Networks (NNs) have provided an alternative approach to data analysis and ore reserve estimation. Unlike the traditional geostatistical methods, neural network uses a highly non-linear complex algorithm to do the estimation. Although Neural Networks have been demonstrated to be attractive alternatives as with every new techniques, there are questions which remain unanswered. This paper presents a comparative analysis with different types of metamodeling approaches -- Triangular, Kriging, Spline, and Neural Network. The neural-network is organized in a multiple-layers and Back-propagation model is used to handle the non-linearity and hidden slabs for smoothing the predicted results. With multiple dimensional and very noisy drill hole sample data, the ore grade is predicted and the overall performance is validated by the analysis of R-squared (R2), Root-Mean-Squared (RMS), and contours of ore grade spatial variability. The ore grade and tonnage of estimated outputs are also compared with various cut-off grades.

Jan 1, 2003

By G. M. L. Robinson

Mineral Processing Wastes, as defined by the Environmental Protection Agency (EPA), has determined that most of the mine wastes will be regulated pursuant to subtitle D (Solid Waste Regulations) of the Solid Waste Disposal Act while specific mine waste categories will be regulated within the framework of the Toxic Substance Control Act. Though EPA's determination currently relieves the industry of the regulatory constraints mandated by the Resource Conservation and Recovery Act (Hazardous Waste Regulations) Subtitle C regulatory framework; the industry is not granted immunity from historical or current environmental regulations related to listed or characteristically hazardous or solid wastes. Because of the current regulatory trends and the need to implement cost effective remediation alternatives; advanced currently available on-site remediation technologies are available to minimize, reduce, contain or prevent environmental impacts related to mining and processing activities. In light of industry technical needs, an overview of the research and commercially available remediation technologies will be discussed and a brief discussion of the strengths and weakness of each technology will be presented. Technologies to be discussed includes stabilization, solidification, soil wash, soil flush, thermal distillation, pump and treat, metal extraction, centrifuges, filter presses, bioremediation, and incineration.

Jan 1, 1992

Integrated mining information and process control systems can reduce information delays, enhance decision making and improve the responsiveness of mining operations to, for example, variations in market conditions, mineral grades and ground conditions. This paper examines developments in the areas of: monitoring, data analysis and diagnosis,' communications systems; integrated mining support system;, and process and machine control. It concludes that the development of a comprehensive information technology plan is fundamental to the phased implementation of these technologies. In addition, hardware and software standards and concurrent digital design and simulation practices in selected manufacturing industries are examined and concluded to have relevance to the mining industry. Integrated information and process control systems will lead to emergence of the "digital mine". Such advances in mining information infrastructure as well as mining equipment will enable mining operations to shift from mass production methods to leaner production techniques. "Lean mining" aims to enhance and accelerate cash flow over the life of a mine by focusing on reduction of' throughput times; stockpiles for volume and quality control; and wastage and rework.

Jan 1, 1995

By M. Moats, I. E. Paschalidou, K. Awuah-Offei

Tellurium (Te) is a rare metalloid that is predominantly produced from the treatment of anode slimes formed during copper (Cu) electrolytic refining. The US Government lists Te as one of the 50 critical minerals, partly, because of its use in thin-film photovoltaic (PV) technology. Given policy initiatives to increase Te production, it is important to evaluate the life-cycle environmental impacts of Te recovery as a by-product of Cu processing. The literature contains a few specific life cycle assessment (LCA) studies of groups of metals that include Te without proper regard to impacts per life-cycle stage of Te production or the effect of allocation on the results. This study builds an LCA model of the production system of Te from anode slimes treatment to evaluate the effect of allocation on life-cycle impacts. We build life cycle inventories using data from the Ecoinvent v3.7.1 database, literature, and engineering calculations and allocate impacts in proportion to products’ mass and economic value. The results show that economic value-based allocation yields greater impacts than mass-based allocation indicating the significant effect of the allocation approach on life-cycle impact estimates.

Feb 1, 2023

By T. M. Biddle

If an accident occurs at a mine, the mining company, its parent and affiliates, and its supervisory employees may face substantial -- and sometimes unexpected -- liabilities and costs. This presentation surveys the likely sources for post-accident exposure, including wrongful death and personal injury claims, mine closure/operational disruptions, and government civil and criminal actions against the company and its employees.

Jan 1, 1986

By Duane A. Smith

Introduction From the days of the Spanish in the eighteenth century, Colorado's San Juan mining district has attracted miners and public interest. The Spanish left behind names - San Juans, La Plata, Animas, legends of lost mines, and the remains of a few scattered mining operations. They came, but did not stay. Again in 1860-61, as a spinoff of the Pike's Peak gold rush, prospectors climbed the mountains and descended into the canyons searching for gold. They found some, not enough to convince them to remain and confront the isolation, often hostile environment and the Utes, who rightfully felt this to be their home. Not until the 1870s did miners come to stay. In their wake little camps grew in the high valleys and squeezed into narrow canyons. Nowhere else in Colorado were there more rugged mountains, a higher average elevation, nor a climate that one old Swede said was "three months of mighty late fall and nine months of winter." The San Juans proved eventually to be a mineral treasure chest. At the moment, however, the prospectors sought gold. Then they discovered silver deposits and the first rush was on. It got started just in time to be completely overcome by the Leadville excitement. At Leadville, investors almost fell over themselves to buy claims and stock in the hopes of becoming another millionaire like Leadville's own Horace Tabor. The San Juaners could only look from the sidelines and speculate how it might have been had fate been kinder. Fate was seldom kind, as these pioneers quickly discovered. From the mid-1870s on, the San Juaners wrestled with some major problems. And the fate of their district rode in the balance. The problems they faced were similar to those of other Colorado districts, compounded by their geographic isolation. Every mining district needed the best transportation system available, experienced investors combined with sound investment, and mineral reserves to develop. The San Juans offered the last in abundance. It was hoped the first two would appear. Railroads - much needed transportation link Nothing was more desired than railroad connections, the penultimate nineteenth century form of transportation. Colorado's own, the Denver & Rio Grande, resolved the issue with its mountain-hugging narrow gauge. As early as the mid-1870s, the D&RG dreamed of tapping this potentially lucrative market in southwestern Colorado. A national economic depression and then the Leadville silver excitement prevented immediate construction. Not until 1879-80 did survey crews start work.

Jan 2, 1988

By M. Plesha, A. Zubelewicz, K. Connor, T. B. Belytschko, O&apos

INTRODUCTION The Northwestern University Rigid Block Model (NURBM) has been extended to explicitly model dilatant behavior of rock joints. By incorporating dilatancy, the resistance to shear displacement and slip, which previously was limited to simple Coulomb friction, along edge-to- edge contacts is now provided by contact roughness as well as frictional resistance. The explicit formulation is based on concepts presented by Plesha (1985) in which a plasticity-based phenomenological approach was used to model dilatant joint behavior. This approach has been modified to allow for joint closure upon reversal of shear deformation. After presenting a brief description of the new joint constitutive relationship, model behavior will be illustrated with two examples. The first involves a simple two-block model to simulate a cyclic direct shear test of a single joint. The second example involves simulation of a large cavern in a moderately jointed rock mass subjected to cyclic excitation. It will be shown that in- creasing joint roughness increases cavern stability by interlocking of adjacent blocks. JOINT CONSTITUTIVE RELATIONSHIP Within NURBM adjacent two-dimensional rigid blocks interact along their common edge-to-edge contact with contact forces transmitted at the contact midpoint. The contact constitutive relationship was originally restricted to a Coulomb friction yield criterion with no tensile stresses permitted along the smooth contact surfaces. The local coordinate system for any contact is described as shown in Figure 1 with the elastic stresses and displacements related by the linear- elastic constitutive law: [ ] The contact microstructure has been modeled as Patton-type saw-tooth surfaces such as shown in Figure 2. Sliding can be active along the right asperity with angle aR and length lR or along the left asperity with angle a and length lL. In general, aR and aL will difkr as will lR and lL but for purposes of this paper it has been assumed that these angles and lengths are identical. By a simple transformation, the microscopic asperity stresses can be expressed in terms of the macroscopic contact stresses [ ] If Coulomb friction is assumed along the asperity surfaces, the plastic slip condition will be [ ] where µ is the friction coefficient with the convention that compressive stress is negative. When F is negative, the behavior is elastic and when F is zero, slip can ensure. When plastic slipping does occur, it is assumed that the relative tangential and normal displacements between the two contacting rigid blocks are additively composed of recoverable elastic parts and nonrecoverale plastic parts, [ ]

Jan 1, 1986

By W.J. Atkinson

The first recorded discovery of diamonds in Australia was in 1851 from New South Wales. Subsequent prospecting has shown alluvial occurrences of diamond to be relatively widespread through much of the Tasman Fold Belts of Eastern Australia and production to date is estimated to be some 500 000 carats from a number of 'small alluvial fields. Despite extensive exploration though, no primary rock source carrying significant diamond contents has ever been confirmed in Eastern Australia. Conversely, diamond exploration of the older Western and Central Cratons of Australia over the past 30 years has discovered 12 fields containing 360 kimberlites, lamproites and lamprophyric volcanic pipes, dykes and other intrusives, of which 180 have been confirmed to be diamondiferous. Only one pipe however, the 1200 Ma high grade Argyle lamproite and associated near-by alluvials, has proved to be economically exploitable with current annual production of 40 million carats valued at approximately US$400 million. Production from the open-pit will be sustainable until at least 2003. This paper briefly summarizes the history of diamond discovery in Australia, principal diamondiferous provinces and deposits, current exploration activities and the potential for future discoveries.

Jan 1, 1995

By J. Andres

"Freeport-McMoRan’s Sierrita operations refines molybdenum disulfide in a ferric chloride leach to remove impurities. To understand bottlenecks in the leach process and the true capacity of the leach system, a cross-functional team was established to look at theoretical models, kinetics of the leaching process, equipment limitations and operational strategies. A series of in-plant tests were run which resulted in a road map for improved throughput. INTRODUCTION Molybdenum, a vital component in the steel industry, is often found in nature as molybdenum disulfide (MoS2). Molybdenum disulfide deposits can exist as standalone components in an ore body, or can also be found within copper porphyry nodes. Processing for these copper/molybdenum porphyry ore bodies involves a first stage of flotation to produce a bulk concentrate before separation of the copper and molybdenum concentrates in a second stage of flotation. In this second stage of flotation, a reagent is added to suppress the copper particles, while allowing the molybdenum disulfide particles to remain hydrophobic and continue to float. This separation is very good at keeping the molybdenum out of the copper concentrate; however a portion of the copper continues to float through the circuit. As a result, there is typically some amount of copper in the final molybdenum concentrate. This copper must be removed in order for the molybdenum disulfide product to meet product quality specifications. Once the raw molybdenum disulfide product has been made, a separate process must be applied to remove any copper, lead, or other impurities remaining in the concentrate. This process usually involves the selective leaching of impurities out of the bulk solid. Gupta mentions three specific types of leaching agents, sodium cyanide, ferric chloride, and hydrochloric acid for the removal of sulfide impurities. Sodium cyanide is useful for the removal of copper compounds such as bornite, covellite, and chalcocite.1 Sodium cyanide solution dissolves these copper compounds, and the remaining molybdenum solids are filtered to produce a pure molybdenum concentrate. Ferric chloride works similar to that of sodium cyanide, but is particularly efficient in removing chalcopyrite and galena compounds. These compounds are easily chlorinated at elevated temperatures, producing copper chloride and lead chloride, through the reactions presented below:"

Jan 1, 2015

By Jr. Pickering

Kaolin is mined from extensive sedimentary formations in the eastern Amazon River Basin of Brazil. Production began about 25 years ago from 30 meter thick beds of ultra-fine particle clay of superior viscosity along the Jari River north of the Amazon. Operated by CADAM S.A., capacity now exceeds 750,000 tonnes per year ot high glossing paper coating kaolin product. South of the Amazon on the Capim River are two new operations: Para Pigmentos S.A. and Rio Capim Caulim S.A. The purity , and large coarse plate-shaped particles of these Capim kaolins support production of superior brightness and whiteness paper coating and filling grades. Annual capacities are reported to be 150,000 to 300,000 tonnes each, with expansions planned. Most of Amazon area kaolin production is shipped to western European, Asian, and North American markets.

Jan 1, 1999

By M. F. Corcoran

Rapid advances have been made in the past few years in the application of automatic controls and instrumentation to iron ore pelletizing plants. Present practice in applying instrumentation and control to the Grate-Kiln system of iron ore pelletizing is described. Major control points and loops are tabulated. Future trends in the application of digital control including computer data logging systems are described.

Jan 1, 1965

By K. Huttu, A. van Wageningen

"The Kittila underground mine is extracting one of the largest known gold deposits in Europe and has an estimated mine life through 2034. The Kittila mine is located in the Lapland region of northern Finland, approximately 900 kilometres north of Helsinki and 150 kilometres north of the Arctic Circle. The ore at the Kittila mine is refractory, making gold extraction relatively difficult because the gold is generally locked inside the two main sulphide minerals – arsenopyrite and arsenic-rich pyrite. The orebody consists of a complex pinch-and-swell structure including up to 100 different gold mineralization lenses. Fluctuating gold prices and other economic considerations increase the need to maintain and update the mining plans more frequently. Over 3,000 stopes need to be designed and optimized once a year for the LOM-plan and more frequent updates are needed for mid- and short term plans as well as production studies. As a large part of ore body is very sensitive to cost and gold price changes, stope optimization is crucial to find the best possible production scenario for every moment. Kittilä has gone through several methods for stope design and optimization. Most recently the Deswik Stope Optimizer (Deswik.SO) has been successfully used. Dewsik.SO has helped Kittilä to design and optimize stopes in a timely and cost efficient manner. Together with the Deswik suite of planning tools, reliable and auditable plans are created. This paper describes the methods used for stope design and optimization at Kittilä. THE KITTILÄ MINE The Kittila underground mine in northern Finland is extracting one of the largest known gold deposits in Europe. Kittila achieved commercial production on May 1, 2009, becoming Agnico Eagle’s first mine to open outside of Canada. The Kittilä orebodies were initially mined from two open pits – Suuri and Roura – and underground operations were added in October 2010. The pits were mined out in November 2012, so mining is now entirely underground in the Suuri and Roura deposits. Additional, small open pits will mine any remaining near-surface reserves in the future. The Kittila mine is located in the Lapland region of northern Finland, approximately 900 kilometres north of Helsinki and 150 kilometres north of the Arctic Circle. With a mine life estimated through 2034, Kittila is Agnico’s longest-life mine. The mine’s proven and probable reserves contain 4.7 million ounces (32 million tonnes at 4.6 g/t gold). Ore has been mined from underground since 2010. The original 3,000-tonne-per-day operation underwent an expansion project to increase the throughput capacity of the mill by 1,000 tonnes/day, starting by the end of 2014. The region around the Kittila mine is underlain by mafic volcanic and sedimentary rocks of the Kittila Greenstone Belt oriented nearly vertical. This greenstone belt is similar to those hosting Agnico Eagle's Canadian deposits in Quebec’s Abitibi region and Nunavut. At the contact point between iron-rich and magnesium-rich rocks lies a 100- to 200-metre-thick structural zone known as the “Suurikuusikko Trend”. This trend hosts the Kittila deposit, where multiple mineralized zones have been traced over a strike length of more than 25 kilometres."

Jan 1, 2015