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By L. W. T. Weitzel

"This paper reviews the Falconbridge- SMRQ’s Raglan project in northern Quebec and the process that was used in developing its current long-term mine plan. Challenges were many and not only limited to the longevity of the project, numerous ore deposits (both underground and open pit), and a 40 km property strike length. As a result of its remote northern location, other factors such as progressive reclamation, leachable mine waste, water treatment, and waste management were also part of the plan. A combination of modern planning tools were used to formulate the plan including DataMine, Mine 2-4D, AutoMod Simulation, and an Excel-based financial spreadsheet to bring the total plan together. The focus of the paper is to show the complexity of modern mine planning and associated economic modelling of mine processes. IntroductionThe Raglan project is located 1660 km directly north of Quebec at the northern tip of the Quebec Peninsula in Nunavik. The main property is 40 km in length stretching from the Donaldson airport area at the eastern edge of the property to East Lake at the western edge. The Deception Bay port is 90 km north of the main complex/mill situated at Katinniq which lies approximately in the middle of the property (Fig. 1). The mine processes 1 000 000 tpy of ore from both open pit and underground sources. The mill is forecasted this year to produce more than 150 000 t of concentrate grading more than 18% nickel. All personnel and critical cargo are transported to the site via a company-leased 737 jet from Rouyn-Noranda where the main administration office is located. The majority of cargo is shipped to the site via Deception Bay from Quebec and on the return trip, nickel concentrate is shipped back. From Quebec, the nickel concentrate is sent by rail to the Falconbridge smelter in Sudbury and on the reverse rail haul, nickel matte from the smelter is sent to Norway via Quebec."

Jan 1, 2003

Several Approaches to Enhance the Bioleaching of Enargite Some approaches were investigated to enhance the recovery of Cu from enargite by bioleaching with Acidithiobacillus ferrooxidans using the galvanic interaction with pyrite and activated carbon, and with thermophilic bacteria, Acidianus brierleyi. Addition of pyrite initially enhanced Cu leaching by the Galvanic effect, but after that the formation of secondary minerals passivated the surface of enargite in inoculated batches. Activated carbon improved Cu recovery from enargite much better than pyrite, when it is contacted with enargite. Recovery of Cu from enargite has been recorded to at largest 2.4 per cent within 30 days in the presence of activated carbon when mesophilic bacteria were inoculated at 25¦C. The recovery of Cu from enargite was drastically enhanced by inoculation of thermophilic bacteria, Acidianus brierleyi, up to 60 per cent within 40 days at 70¦C and still not leveled off after 40 days unless the formation of Fe(III) precipitates occurred. After 40 days dissolved molar ratio of Cu/As is around 5.2, suggesting that metal-deficient sulfides and/or ferric arsenate might be formed on the surface of enargite.

Sep 13, 2010

By S. H. Ash

THE MAGNITUDE of the anthracite industry's drainage problem in the Northern field of Pennsylvania is realized when it is known that, for the 8-year period 1944-51, all pumping plants in this region pumped an average volume of 112.5 billion gallons of water from the mines to the surface each year. This is over 214,000 gallons per minute pumped against an average hydrostatic head of 400 feet each year for that period (12).4 By comparison, Lake Wallenpaupack, the largest artificial body of water lying wholly in Pennsylvania, contains 71 billion gallons of water in its 24-square-mile area; the average volume of water pumped from the mines in the Northern field each year during the 8-year period was 58 percent more than the volume impounded in Lake Wallenpaupack. The natural configuration of the drainage area overlying the Northern field subdivides the total area into two major drainage areas-the Lackawanna River drainage area and the Susquehanna River drainage area overlying the Wyoming Basin. Although the 169-square-mile drainage area overlying the Wyoming Basin is slightly less than half that of the Lackawanna River drainage area (10), the total volume of water pumped to the surface from mines in the Wyoming Basin is 21 percent more than the total volume pumped to the surface from mines in the Lackawanna Basin. From this, it is apparent that the Susquehanna River and the pervious deposits in the buried valley over which it flows in its course across the coal measures of Wyoming Valley is the greatest single source of mine water affecting mines in this area. Because of its relatively flat terrain, the wide flood plain of Wyoming Valley does not facilitate rapid runoff; consequently, much of the surface water seeps directly into the buried-valley deposits and eventually into the mine workings.

Jan 1, 1953

By John D. Wiebmer

First, a definition of a small scale miner is in order. The US Bureau of Mines classifies him as one who produces 360 t/d (400 stpd) of ore or less. In Canada, he would be refered to as a "junior company." Mexico identifies the small scale miner as one whose gross income from operations is less than $880,000 per year. A small surface mine in India employs less than 400 people, and a small underground mine employs less than 150. Peru considers a small scale miner one who produces less than 54 000 t/y (60,000 stpy) of ore. Obviously, the term is relative. What may be a small mine in one country is a medium or large mine in another. This lack of agreement is understandable since small scale mining does not often cross national boundaries. Rather, its effects are felt at the regional and local levels within each nation. Its importance doesn't lie with any huge contribution to the GNP or balance of trade. Instead, its value is as a local employer and as a frontrunner in geologic exploration.

Jan 2, 1979

Development of the Boleo Process Flow Sheet and the Direct Solvent Extraction (DSX) Circuit for Cobalt and Zinc Recovery The metallurgical process designed to treat the El Boleo Cu-Co-Zn-Mn ore involves a sulphuric acid leach in seawater under oxidative and then reductive conditions to maximise metal extraction. Copper and cobalt are recovered as cathodes by electrowinning, zinc and manganese as zinc sulphate monohydrate and high quality manganese carbonate, respectively, by precipitation after a number of separation and purification stages. One of the key purification stages of the Boleo metallurgical process is the CSIRO DSX circuit. The DSX circuit was developed using the synergistic solvent extraction (SSX) technology. Initially, a synthetic solution was studied, and by adding 0.4 M LIX63 to 0.5 M Versatic 10 in Shellsol D70, large synergistic shifts were obtained for cobalt (?pH50 4.24) and zinc (?pH50 1.62). After a single contact, the separation factor of metals over manganese reached over 6,000 for cobalt and over 380 for zinc, indicating excellent separation of cobalt and good separation of zinc from manganese, magnesium and calcium. The SSX system was further optimised with the modified synthetic pilot plant solution. The extraction of cobalt and Zn after a single contact was 93 per cent and 70 per cent, respectively, while the Mn concentration in the loaded organic solution was only 0.28 g/L. A proof of principle pilot plant operation was conducted in 2004 and a demonstration pilot plant for final engineering design in 2006 with outstanding performance of the DSX circuit. For the demonstration pilot plant, the overall recovery of cobalt and zinc exceeded 99 per cent with a raffinate containing only 4 mg/L Zn and 1 mg/L Co. The DSX organic system showed no sign of degradation during the pilot plant operation, indicating good chemical stability under the anticipated commercial operating conditions. The DSX circuit will be implemented in the future Boleo processing plant.

Sep 13, 2010

The new legislative regime applying to the mining industry has been in force for nearly two years. However the parameters for the permits required under the Crown. Minerals Act 1991 and the resource consents required under the Resource Management Act 1991 are still being established. Mining operators will benefit from participating in the development of policies and plans currently being formulated by local authorities. The Energy Legislation Amendment Bill currently before the House contains amendments to the Crown Minerals Act to clarify points of uncertainty and to reduce transaction costs where possible.

Jan 1, 1993

By Sneddon N

In November, 1975, Aberdare North colliery was sealed at the surface to extinguish an open fire underground.The fire had developed from a spontaneous heating in one of the open goaf areas of the mine.The mine was re-entered with normal ventilation methods following the isolation of the working district containing the fire. The isolation was accomplished by remotely sealing the open roadways with lly ash emplaced through boreholes from the surface. A subsequent re-entry operation similarly closed the roadways close to the fire and enabled the re-opening of the sealed district.Most of the mine and the underground equipment was recovered after clearing of numerous falls and production recommenced on 25th October, 1976.

Jan 1, 1978

By H. Sekimoto, T. Matsuoka, K. Yasuhara, M. Ota, S. Akutagawa

A magnetic anisotropy sensor is used for nondestructive measurement of stress on surfaces of a ferromagnetic material, such as steel. The sensor is built on the principle of the magneto-strictive effect in which changes in magnetic permeability due to deformation of the material is measured in a nondestructive manner, which then can be translated into the absolute values of stresses existing on the surface. This technique was applied to measure stresses of H-beams used in tunnels. The results show that this method could be one of the promising technologies for non-destructive stress measurement for safe construction of underground structures. Une sonde magnétique anisotropique est utilisée pour des mesures non-destructives de stress sur la surface d' unmétal ferromagnétique, comme l'acier. La sonde est construite sur le principe de l'effet magnéto-strictif dans lequel les changements dans la perméabilité magnétique due à la déformation du metal est mesurée avec une manière non-destructive, qui peut être alors traduite en valeurs absolues des stress existants à la surface. Cette technique a été appliquée pour la mesure de stress des poutres en H utilisées dans les tunnels. Les résultats montrent que cette méthode peut être l'une des technologies promet tantes concernant les mesures non-destructives de stress pour des constructions sûres de strcutures souterraines. Ein magnetischer Anisotropie-Sensor wird für die zerstörungsfreie Messung von Spannungen an Oberflächenvon ferromagnetischen Materialien wie z.B. Stahl verwendet. Der Sensor kann Änderungen in der magnetischen Durchlässigkeit auf Grund von Verformungen des Materials erkennen, die dann in Absolutwerte der Spannungen an der Oberfläche umgerechnet werden können. Die Methode wurde auf Messung von Spannungenvon H-Balken in Tunnels angewendet. Ergebnisse zeigen, dass dies eine vielversprechende Methode für diezerstörungefreie Messung im Tiefbau ist.

Jan 1, 2003

By A. Broussaud, J. D. McKay

Benefits analysis of adaptive Expert control systems operating at plants in Africa and the United States are presented. Proper statistical tools and techniques are discussed. Technical and practical pitfalls of strategy comparison are also presented and illustrated with from published data. Advantages and disadvantages of a “Pay for Performance” approach to a project are reviewed.

Jan 1, 2001

From a vast army of workers to gargantuan machines to immense volumes of material being moved, almost everything about the Port of Miami Tunnel (POMT) project points to tunneling on a massive scale. Almost.The star of this underground and underwater show is a Herrenknecht tunnel boring machine (TBM,) nicknamed ?Harriet? by a local Girl Scout troop. With her 12.9-m- (42.3-ft-) diameter cutting head and a total length of 139 m (457 ft), Harriet is boring through thousands of cubic meters of clay, dirt and sand, which is often mixed with coral and other materials, to create two 1,280-m (4,200-ft) traf?c tunnels connecting Watson Island and the Port of Miami (Dodge Island) beneath Biscayne Bay, FL. But in the midst of all of the oversized equipment and machines, a strong contender for the best supporting nod goes to a relatively tiny machine: the Brokk 400. Bouygues Civil Works Florida crews are using the compact, remote-controlled and electric-powered machine to excavate five cross passages between the twin traffic tunnels. The pas-sages will be essential to the safety of people who drive their vehicles under the bay every day.

Sep 1, 2013

During August, 1926, with the consent of Mr. Schell, mine manager, the writer conducted a mill test on this company's concentrators. Mr. Schell not only gave him his permission, but rendered all possible assistance. Although it was impossible to take all the samples one could have wished to obtain, yet the salient points of the mill flow-sheet were sampled for a continuous period of eight hours, and from these samples and separate data supplied by the manager, valuable information was collected.THE MINEThis is a true vein-type of mine; the lode formations, striking almost due north-south, cut the large porphyritic intrusion at right angles. There are three distinct veins on this property - parallel, persistent, and dipping at an angle varying between 40° - 50° to the horizontal.The country rock is very sound, and timber, save for the small amount required for ore chutes, is entirely absent from all mine workings.The lode varies from a width of 1 in. to 8 in., but the stopes are carried forward with a minimurn width of about 30 in.The mine is particularly dry for a West Coast property, and conditions underground are very favourable. Air drills are used...

Jan 1, 1928

By Frances H. Clark

IN wartime, the fabrication and use of metals assumes increased importance, for a modern war of sizable proportions cannot be undertaken with- out a vast supply of this material. Light alloys of aluminum and magnesium, which were comparatively unknown in the last war, will play an important role in this one. Due to research on a vast scale in the interim of years, industry is today well equipped to fabricate metals on an enormous scale. Research for the past year has been most productive and a comprehensive survey in the space of this article would be impossible. It is hoped that the stressing of a few items here and there out of a great quantity of able work will indicate in a small way the advances made within recent times. Specific references to the literature will be omitted at the Editor's re- quest but some authors of papers that I have found of special interest are mentioned.

Jan 1, 1940

By Randy N. Powell

The Pipeline gold ore body was discovered in Lander County, NV in March 1991. Construction of the new mine and mill did not start until early March 1996. The $289-million project was placed on a fast-track development schedule upon completion of permitting and corporate approval. The mine and mill were commissioned 11 months after the start of construction and the project ended up $40 million under budget. Project design and construction management were provided by Placer Dome Project Development Division (PDD). History The Cortez Joint Venture has operated in northeast Lander County since the late 1960s. The business structure is comprised of 60% Placer Dome and 40%Kennecott Exploration. Throughout the years, production has been from several small open-pit deposits— Cortez, Horse Canyon, Gold Acres and now Pipeline.

Jan 1, 1999

A large lab apparatus was designed using a scale-down methodology based on the design legacy of the current FLSmidth commercial forced air flotation machines. This new apparatus, along with a new test methodology, was used to evaluate new rapid prototype concepts. The apparatus was designed to monitor bubble size, power, pumping capacity, Jg, velocity profiles, froth character, and tip speed. The methodology developed follows a sequence that goes from hydrodynamic tests and solids suspension tests to a flotation kinetic test. This methodology has been demonstrated to be a good tool to determine the effect of machine design changes on flotation.

Jan 1, 2012

By Thomas A. Milne

As part of the broad program to improve the safety of underground coal mines, the Pittsburgh Mining and Safety Research Center sponsored several detailed studies on the inhibition of coal dust-air explosions. The present study was one of these. The goal of the research was to advance the development of improved coal-dust explosion inhibiting agents by determining, on a laboratory scale, the basic chemical processes involved in the inhibition of coal-dust flames by dry-powder agents. B. Our Approach Neither the basic molecular processes involved in coal combustion, nor the molecular mode of action of dry-powder agents, are known with certainty. Our approach, therefore, involved the direct determination, by sampling techniques, of species behavior in small, aerodynamically simple flames. To further aid in separating behavior of coal and dry-powder inhibitors, the latter were studied in CH4-air flames.

Jan 1, 1976

By Roberto Folchi, Hans Wallin

Lake Mead, the largest man-made reservoir in the United States, is located about 30 miles southeast of Las Vegas, Nevada. For the construction of Lake Mead third water intake, which is entirely placed underground, an underwater excavation was needed at a depth of 100 m (330 ft): a large surface had to be deepened by 20 m (66 ft) in basalt.

Jan 1, 2012

By James J. Meadows, Jason D. Pampena, Emanuele G. Cauda, Lauren G. Chubb

Exposure to respirable crystalline silica (RCS) can cause serious and irreparable negative health effects, including silicosis and lung cancer. Workers in coal mines have the potential of being exposed to RCS found in dust generated by various mining processes. The silica content of respirable dust in one single mine can vary substantially over both time and location. The current monitoring approach for RCS relies on the use of traditional air sampling followed by laboratory analysis. Results generated using this approach are generally not available for several days to several weeks after sampling, and this delay prevents timely and effective intervention if needed. An alternate analytical method is needed to reduce the time required to quantify the RCS exposure of mine workers. The National Institute for Occupational Safety and Health (NIOSH) has developed a new method using commercially available portable infrared spectrometers for measuring RCS at the end of the sampling shift. This paper will describe the application of the new field-based RCS analytical process for coal mines, including the use of the new method with the existing Coal Mine Dust Personal Sampler Unit. In a case study conducted by NIOSH with a coal mine operator in West Virginia, field-based RCS analysis was completed at a mine site to evaluate the new technique. The RCS analysis results obtained by the field-based method in this case study showed sufficiently strong correlation with results obtained by the MSHA standard laboratory analysis method to allow the mine operator to use the field-based method for evaluating process improvements.

By Thomas D. Kaufmann

Introduction What drives the price of gold? Supply and demand, of course. But in ways far different from the forces that drive the prices of other major metals, such as steel, aluminum, and copper. Gold, in fact, is one of the few commodities where both buyers and sellers are happy when the price goes up. Current production, production costs, and variations in production have little influence on its price. Gold inventories are so tremendous that current production has small impact on the amounts available to the market at any time. Worldwide gold inventory and production The world's inventories seem to be between 78 and 98 kt (2.5 and 3 billion oz). Since biblical times, the gold miners of the world have produced about 98 kt (3 billion oz), mostly in this century. Only small amounts have been thrown away and most of it - more than 78 kt (2.5 billion oz) - remain in bullion, coins, or jewelry. About 40% is held by central banks and other governmental authorities, 30% by private individuals as bullion or coins, and about 30% as jewelry. Except for some of the jewelry and the few industrial applications, this inventory is constantly available in marketable form at a price. By comparison, gold production is indeed small. The US Bureau of Mines estimates that the world produced 1.5 kt (50 million oz) of gold in 1986. Consequently, production increased world inventories by only 2%. Variations in production have a negligible or very short-term effect on the supply and, consequently, on the markets for gold. Although South Africa mines about 40% to 50% of the world's annual production, continuing labor strife there does not seem to have ruffled gold prices. Determining gold's price Gold prices, however, do determine cutoff grades in the mines and, thus, do influence production. Nonetheless, changes in production have little impact on the inventory supply. Consequently, it has small influence on the price of gold on the market. With a fairly stable supply, price changes are driven by changes in its demand. Unlike other metals, very little of the demand for gold comes from industry. Dental, electronic, and other industrial uses for gold consume less than 46.6 t/a (1.5 million oz per year). It would be safe to assume that such uses are less than 124 t/a (4 million oz per year) for the entire world. Variations in the 124 t (4 million oz), compared to a supply of 78 kt (2.5 billion oz) of supply can have only a negligible effect. Production net of industrial uses adds perhaps 1% annually to world inventories. This could, in time, affect markets. The increase, however, is mostly absorbed by population growth - more people wanting to own gold - and by gold being put in more attractive forms, such as coins. As an ancient Lydian king discovered, minting bullion permits

Jan 9, 1987

By Jan Pru?ka

This paper describes the sheet pile design for the Line C extension from Ládví station to the North of Prague. The first part of the paper describes the geological conditions and structural configuration of the project. Typical cross sections, the description of the construction stages, and monitoring are discussed. The second part of the paper focuses on the sheeting design method. It describes the method of dependent pressures, that is, how the pressures acting upon a structure depend on the deformation. The design process and verification methodology are described in detail with comparison of the results with in-situ monitoring.

Jan 1, 2011

By Marilia S. de Magalhaes

Keywords: sinter, characterization, agglomeration, iron ore Iron ore sinters are the main burden of blast furnaces for pig iron production. The evaluation of these agglomerates is very important due to their properties affect indirectly the productivity and costs of production of the steel industry. In the sintering plants, the standard procedure of sinter assessment has been carried out by particle size control, bulk chemical analyses, tumbler and/or shatter tests and determination of reduction degradation and reducibility indexes. Microscopy techniques have just been applied to characterize sinters produced in pilot conditions, however, these techniques, the classical ones and the less traditional, allow enhancing the industrial sintering process assessment. For investigation of the phases, microstructures and fabric, reflected-light and scanning electron microscopy(backscattered electrons images) were used; for micro analytical chemical examination, energy-dispersive X-ray spectrometry; for Kikuchi patterns registers, electron backscattering diffraction. In addition to the microscopy techniques, the magnetic behavior was depicted by means of magnetic susceptibility measurements. Iron ore sinters are made up by hematite, magnetite, silicoferrite of calcium and aluminium and silicates. These phases develop either during sintering or, in some proportion, represent remnants of ores and fluxes; this is the case of some hematite and Mg-bearing silicate, respectively. From the magnetic susceptibility results, three different behaviors were determined, which are directly related to the magnetiteproportion in the samples. The phase association and proportion, the sintering conditions andthe quality assessment are some features appraised by such procedures, which reveal themagnitude of this proposal in sintering plants.

Jan 1, 2005