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By A. Tylczak, C. Norman, C. Shook, S. Loif

"There are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes or malfunctioning equipment early, which allows problems to be corrected promptly.Sacré-Davey Engineering in Vancouver has performed over 50 Energy Management studies for various industries including: mining, pulp and paper, oil and gas, etc. Energy Management programs can be used to identify energy reduction opportunities, assess project feasibility, complete equipment selection trade-offs, as well as to monitor and manage energy costs. Benefits of energy management programs are reduced energy costs, reduced maintenance, and increased plant automation. Additionally, energy management can provide access to utility incentive funding and quantify savings which can greatly improve the return on investment of potential projects.Energy management studies are funded by many Utility programs across Canada. There are various programs available for existing plants energy audits, project feasibility studies, new plant design reviews and energy monitoring and targeting, etc. There are capital incentives available which can significantly reduce payback period.This paper discusses how energy management can be used to support mill/mine operations groups, maintenance programs, as well as expansion or green field projects. This paper will also provide an overview of Canadian Utility companies programs and how they can assist mining companies.IntroductionThere are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes and identify malfunctioning equipment early, which allows problems to be corrected promptly."

Jan 1, 2015

By K. P. Black, G. W. Sevick, D. E. Hockley, K. S. Sexsmith, J. T. Chapman

Mineralogical analyses of carbonates in depyritized tailings and pyrite concentrate (from depyritization of the tailings) were completed as part of the tailings characterization for the Crandon Project, a massive sulfide deposit in northeastern Wisconsin. The mineralogical study was designed to determine the proportion of calcium and magnesium carbonates, and therefore the effective buffering capacity of carbonates in the tailings. The depyritized tailings are net acid consuming and will be stored in a surface tailings management area. The pyrite concentrate is net acid generating and will be used as backfill in the underground mine workings. The majority of carbonates in the depyritized tailings were ferroan dolomite containing 10 to 15% iron (by weight) and lesser amounts of siderite and magnesian siderite. The proportion of calcium and magnesium-rich carbonates corresponds to several independent tests of carbonate neutralization potential (CO3-NP) availability. The pyrite concentrate had less CO3-NP, indicating segregation of the carbonates during pyrite flotation. These carbonates reported higher iron contents, consistent with the relatively lower availability of CO3-NP in the pyrite concentrate.

Jan 1, 2002

By P. Miranda, K. Le, G. Maes, R. Peters

"The Mount Milligan Mine, owned by Thompson Creek Metals Company Inc. (TCM), started operations in September of 2013. It is located between the communities of Fort St. James and Mackenzie and is the first major metal mine to open in British Columbia in 15 years. Based on reserves as of January 1, 2014, it has an estimated 22 year mine life with 2.1 billion pounds of copper and 6 million ounces of gold in reserves. Like all commissioning operations, there have been issues achieving design throughput and recovery due to flow sheet design, equipment failures, control philosophy, and reagent scheme. Efforts to improve overall mill performance include equipment modifications, reagent screening and testing, and grind size testing. Applying these changes to the mill and working closely with the mine has resulted in continuous improvement each month as Mount Milligan looks to achieve the nominal design capacity of 60,000 dry metric tonnes per day in the later part of 2015. Considerable focus is being placed into ensuring size reduction equipment is utilized effectively. Additional modifications and tests are being undertaken to steadily improve processes and alleviate restrictions in the mill. This paper will discuss the start-up and present ramp-up history of Mount Milligan, the current mill processes, and the steps taken to achieve expected production numbers.OPERATION BACKGROUNDMount Milligan is an open-pit copper and gold operation wholly owned and operated by Thompson Creek Metals. It is located approximately 155km northwest of Prince George, British Columbia, between the communities of Mackenzie and Fort St. James. The copper-gold porphyry deposit contains a Measured and Indicated Mineral Resource of 706.7 Mt at 0.18% Cu and 0.33 g/t Au, containing 2.84 billion lb. copper and 7.50 million oz. gold. Mine life is currently estimated at 22.1 years (“Feasibility Update – Mt. Milligan,” 2009). The mill is designed to process 60,000 dry metric tonnes per day and produce 400 dry metric tonnes of concentrate per day averaging 25.5% Cu and 40 ppm Au. Concentrate is delivered by truck and trailer to Mackenzie followed by rail to Vancouver for overseas shipping to various customers.Mount Milligan is considered a “zero discharge” operation meaning no process or surface water will be discharged to the environment. As well, stockpiling is very limited and is only permitted for a short period of time. This scenario presents several unique challenges. Scheduling of ore/waste production must be carefully planned as waste rock is used to build the tailings storage facility (TSF). Reagent selection is also important as persistent chemicals will have a tendency to build up in reclaim water which feeds the process water tank."

Jan 1, 2015

By Christopher Mark

Pillar recovery continues to be one of the more hazardous activities in underground coal mining. Safety requires that the roof above the intersection remain stable until after the pillar has been extracted. Artificial supports (timbers and Mobile Roof Supports) arc essential to roof stability, but so is the final remnant stump or pushout. Traditional mining practices usually called for the complete extraction of the final stump, but the recent trend (both in the U.S. and internationally) seems to be towards mining plans that leave a remnant stump. For this study, a sample of roof control plans from the Mine Health and Safety Administration (MSHA) Coal Districts were analyzed to determine current pillar recovery practices. Both full- and partial- extraction plans were included. Special attention was paid to whether plans require that a final stump be left, and whether requirements regarding the dimensions of the remnant stump are included. Foreign experience with final stumps is also summarized. It seems that the risk of major pillar falls can often be reduced by leaving final stumps that are large enough to protect the intersection, but small enough that they do not inhibit the caving of the gob. Because final stumps are often irregular in shape, a new approach for estimating their strength is described. Analyses were conducted to assess the effect of seam height and depth of cover on the potential variation in the size of remnant stumps.

Jan 1, 2001

Impala Platinum?s No.16 Shaft mine is currently under construction and is expected to reach full production of 256 500 tons per month by 2014. Mining will start at 1 260 m below surface with a maximum mining depth of 1 535 m where virgin rock temperatures of 56.6°C will be experienced. As a result of depth, high virgin rock temperature and narrow reef mining, an expected total of 31.5 MW[R] of air cooling capacity will be required to achieve acceptable underground conditions. This will be achieved by cooling mine intake air in a single dedicated air cooling installation located on surface. The compact installation includes air cooling spray chamber, refrigeration machines, condenser cooling towers, evaporator and condenser water reticulation as well as all electrical and control systems. Construction and commissioning of the first phase of this air cooling installation has recently been completed on a turn-key contract basis.

Jan 1, 2009

By J. A. Cooper

The objectives of this research were to define the chemical composition and physical characteristics of the aerosols associated with attached radon daughters in operating uranium mines, and to investigate the relationship between these aerosol parameters and operating conditions. Major Results and Conclusions The organic, inorganic and radiological characteristics of test chamber and active U-mine aerosols have been measured as a function of particle size. These measurements represent the first detailed analyses of the organic and inorganic components in U-mine aerosols and the first determinations of the details of the individual and total radon daughter distributions in operating U-mines. The following is a list of the major results and conclusions:

Jan 1, 2012

By M. J. Beus, B. Stewart, S. Iverson

Synopsis U.S. Mine Safety and Health Administration (MSHA) accidents statistics have identified ore-pass hazards as a significant safety problem in U.S. underground metal mines. The statistics show that nearly 75% of injuries are directly or indirectly related to pulling or freeing of ore-pass chutes, the use of hand tools in ore passes, fails of broken rock in ore passes and structural failures of chutes or gates and ore-pass walls. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) are investigating hazards in and around ore passes in hard rock mines. Risk assessment methods, such as fault-tree analysis, have been employed to identify the most probable causes of orepass failures, define research priorities and analyse the factors that result in malfunctioning and unsafe ore passes. Static and dynamic loads are being measured in a laboratory setting with the use of a reduced-scale orepass mock-up. Field tests are being initiated in mine ore passes to determine static and dynamic loads. Data from the test ore passes are being compared with data from the mine to characterize true system behaviour. Computer modelling with the use of closed-form solutions, finite-element analyses and a newly developed particle flow code predicts static and dynamic leads from the flow and the impact of ore and waste in the ore pass. Preliminary results indicate that dynamic impacts from ore and waste rock might be considerably greater than expected. The total static load is substantially less than is typically used fur the structural design of chute and gate support members. It is suggested that damping factors, normal and shear stiffness and mass frictional characteristics have a significant effect on particle flow and resulting impact loads. This is being verified with the use of results from laboratory tests, field tests and particle flow analyses. Ore passes are vertical or steeply inclined openings in a rock mass through which ore and waste are transported and where they mar also be stored. A typical underground mining system is shown in Fig. 1. The arrows indicate the locations of ore passes and loading pockets and their relative configurations. The control of material flow is potentially one of the most hazardous operations in underground mining. According to MSHA data. most of the ore pass-related accidents in the U.S.A. are associated with the loading-unloading cycle and removal of blockages from ore passes. In particular, attempts to free ore hang-ups have resulted in multiple fatalities. The hazards are obvious; there is uncertainty as to when the ore will break loose and miners are unable to escape falling rock to a safe location. Although ore passes and chutes and gate systems for underground metal and non-metal mines roust meet the requirements specified in the U.S. Code of Federal Regulations (CFR). Parts 57 and 75, recent structural failures of ore-pass linings and gates have underlined the lack of adequate ore-pass design standards available to both MSHA enforcement staff and mine engineers. Because of the importance of an ore pass to the safe operation of a mine design criteria need to be assessed and new guidelines developed. Researchers at the Spokane Research Laboratory of the Nationals Institute for Occupational Safety and Health (NIOSH) are investigating hazards in and around ore passes in hard rock mines and studying design criteria for ore passes. The near-term goal is to conduct laboratory and field experiments and computer modelling to evaluate the ore-pass design criteria currently used. Literature searches, field site

By U. E. Brown

This papery describing the mining methods employed by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the United States. The Bunker Hill and Sullivan mines are situated in the western part of the Coeur d'Alene district at Kellogg, Shoshone County, Idaho. The mines were discovered during the summer of 1885 and except for two short periods of labor trouble, between 1890 and 1900, have been in continuous operation. About 575 men are employed at the mine. The production is about 1,400 tons of lead-silver ore per day. This is treated in the company's concentrator and smelter at Kellogg.

Jan 1, 1931

By Y Yang

This paper discusses various issues surrounding the metallurgical control for furnaces, especially focusing on processes with long time-constants and æmetallurgical memoriesÆ. Examples will focus on furnaces accepting particulate and sometimes ill-defined feeds, eg submerged-arc furnaces, blast furnaces, secondary scrap smelting operations, recycling operations, waste incinerators, etc. Generally, because of the usually higher metallurgical time constant of these furnaces, these reactors have to be controlled in a feed-forward manner by the use of a hybrid of æblack boxÆ or empirical and ægrey boxÆ semi-empirical first principles metallurgical modelling and simulation techniques in a supervisory metallurgical control capacity.

Jan 1, 2000

By Dave Marsh, John Goode, Niels Verbaan, Kevin Bradley, Henrie Notzl

The mineralogy of the Avalon Nechalacho deposit is complex with significant fractions of HREEs, Zr, and Nb found in refractory minerals such as zircon and fergusonite. Sulphuric acid baking followed by water leaching can be used to extract REEs from flotation concentrates, but acid baking does not completely "crack" the zircon and fergusonite, so the extractions of Zr, Nb, and HREEs are not high. An alternative flowsheet has been developed that is able to obtain significantly improved extractions of HREEs, Zr, and Nb from flotation concentrates or acid bake residues. This is accomplished by cracking the zircon and fergusonite minerals with caustic soda at high temperatures, followed by water washing to recover excess caustic soda and soluble sodium silicates and phosphates. REEs, Zr, and Nb in the solid residue can then be solubilized with HCl or H2SO4. This paper highlights some of the findings from an extensive laboratory program and discusses several flowsheet implications.

Jan 1, 2014

By P J. Dailey, S L. Burchell, R F. Chiappetta

In recent years, high-speed motion picture photography has become a powerful diagnostic tool and technique to study, analyze, evaluate, and aid in blast designs. Production blasting, typically lasting less than two seconds, requires an extended time base for observation and clarification of short-lived phenomena. Information obtained from high-speed photographic analysis is categorized into two main groups.

Jan 1, 1989

Editor?s note: Each year, the June issue of Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue. Thank you to the industrial minerals annual review editor, to the technical committees chair and vice-chair, and to the authors of the individual commodity profiles. Jim Norman, member SME, of GeoTrans, Inc., is the industrial minerals annual review editor. SA Ravishankar, member SME, of Cytec Industries, is chair of the industrial minerals technical committees. Technical committee vice chairs include: ? Abani Samal, member SME, of Pincock Allen & Holt, agricultural minerals. ? Aaron McMahon member SME, of Pincock, Allen & Holt, ceramics and refractories. ? Bradley S. Van Gosen, member SME, of the U.S. Geological Survey, chemical raw materials. ? Mark Zdunczyk, member SME, of Continental Placer, Inc., construction materials. ? Jerry Gauntt, member SME, of JEG Minerals Consultants, fillers and pigments. ? Michael Cheshire, member SME, of Indiana University, sorbents, filters and process aids. Their help makes possible this June industrial minerals issue. On behalf of ME readers, the editors thank them.

Jan 1, 2008

By Edmond Chin

The land mass of the Asia and Pacific region comprises 11 million square miles or about 15% of the total Earth's land area. The bulk of the region is contained on the Asian continental land mass. Australia, the world's largest island or the world's smallest continent, alone is almost as large as the continental United States. The islands of New Zealand, New Guinea, Borneo, Sumatra, and Honshu are among the largest in the world. Collectively, they constitute a land area of 1.1 million square miles or an area about one-fourth the size of the United States. The countries in the Asia and Pacific region represent some of the most vibrant economies in the world. Japan is undisputed as one of the world's leaders in manufacturing and commerce. Hong Kong and Singapore are significant both as entrepôt and banking centers. The economies of Australia, the Republic of Korea, and Taiwan compare favorably to the level of the industrialized countries in western Europe. Indonesia, Malaysia, the Philippines, and Thailand have maintained strong economic growth during the past two decades. All these countries in the Asia and Pacific region collectively constitute a significant bloc as to raw materials production and consumption, as to manufacturing, and as to world trade.

Jan 1, 1992

A working understanding of present coal mine communications equipment and its usage is an essential prerequisite to the determination of future communications systems needs. As a means of gaining this understanding, a field survey program was planned and implemented. The plan formulated called for obtaining both qualitative and quantitative data from three main areas of interest: the types, physical condition, and performance characteristics of equipment presently used in the sample of mines to be visited; the relationship present communications has to safety and productivity; and the practical, future communications needs as de- rived through interviews with present mine management. In compliance with the original plan, the type and physical condition of equipment in use was found through at-mine interviews of personnel responsible for installation and maintenance. Further evaluation was made through the review of equipment instruction books and maintenance manuals and through in-mine inspection of communications equipment and signal distribution networks. The performance characteristics were determined through listening to conversations and noise levels and by talk-testing from randomly selected stations throughout each mine. System operation was evaluated by asking communication system users their opinions and by noting any difficulties personnel had using the systems. Plans in the second area of interest--that of relating communications to mining operations-- were to observe mining operations and usage of communications; to gain insight through interviews with mine management, from mine superintendents to section foreman; and to look for correlation between communications, production, and safety. Lastly the communication systems needs and requirements were determined from first hand interviews of mine personnel, from the analysis that lead to the individual reports on the eight mines, and from an overview of all of the mines studied. The latter was done to find commonality between the needs of the individual mines such that system requirements having the greatest universal value could be derived, thus lowering per-mine cost of equipment through economics of scale. Armed with tape recorders, backgrounds in communications technology, and with an interview questionnaire that was improved as experience was gained, engineers visited the eight mines to obtain the raw data from which the needs and requirements could be developed through analysis. During the first part of the program two days were spent at each mine so that interviews and tours could be completed, and so that full eight hour shift phone usage recordings could be obtained for statistical analysis. One day visits were sufficient for those trips where tape recordings were not made. During the later trips less attention was given to the statistical nature of communications, and more to how communications relates to the total mining operation.

Nov 15, 1974

By R. L. Whiting, H. J. Ramey

The basic study from which this paper was prepared was started as the result of the growing need throughout the world for increasing quantities of energy in all forms. Quite obviously, natural forms of energy that are readily available at low development cost are those in greatest demand. The underdeveloped countries — and particularly those having little or no petroleum resources — are the countries in which the most interest is being shown in the newer energy sources. One of the least expensive energy sources is natural geothermal steam.'-* Although this form of energy has been recognized for centuries, it has been only during the past 20 years that serious efforts have been made to harness it. Natural geothermal steam energy in Italy, New Zealand, Mexico, Japan, and California is now being produced through wells to drive turbines and generate electricity. Further, active exploration for natural geothermal steam is being conducted in Hawaii, Fiji, Taiwan, Chile, Russia, Greece, and Katanga. It is surprising to find that most geothermal steam exploration is in the "steam seep" stage. That is, surface studies are made and exploratory wells are drilled in the general area of steam seeps. However, in the larger geothermal steam areas, there have been efforts to apply the most modern geological and reservoir engineering principles in order to define the reservoir parameters, particularly those relating to estimates of reserves and future productivity. This paper is concerned with the development of appropriate equations and techniques to facilitate these estimates. Production of natural steam or hot water presents problems different from those experienced in the production of oil and gas. For example, steam or hot water systems may be essentially single-component systems, while hydrocarbon systems are most frequently multicomponent fluid systems. Heat effects are much larger for water than for hydrocarbon systems; and the natural steam production may or may not be isothermal, while production of petroleum reservoirs is considered normally to be isothermal. Petroleum reservoir engineering principles may be applied to natural steam or hot water reservoirs if the inherent differences in the systems are considered. The basic considerations involved in geothermal steam reservoir engineering are: thermodynamics, physical and thermal properties of water, materials and energy balances, fluid influx, and performance matching and predicting. Thermodynamics Fig. 1 is a pressure-temperature diagram for the liquid-vapor region for pure water, showing the critical point and five other points representing possible initial conditions for a geothermal steam reservoir. To generate a physical appreciation for the mechanics of natural steam production, it is helpful to consider

Jan 1, 1970

By K. Bartholomew

The Functional Performance Equation for ball milling circuits provides plant staff with a new means to improve circuit performance. However, successful execution of a plant processing performance improvement project, with verifiable improvements, requires a significant number of accompanying steps beyond using this equation. In order to identify and articulate all these steps, a study was undertaken with the metallurgical staff from two milling operations and process application specialists from a grinding media manufacturing company. “Task analysis” of improving plant grinding performance was carried out. This analysis identified the required steps, and ultimately yielded a “Plant Grinding Circuit Processing Performance Management/ Improvement System.

Jan 1, 2015

By Joe Pezo

Desde 1999 se desarrollaron pruebas de lixiviación de concentrados en la planta LESDE de Toquepala con el propósito de evaluar las recuperaciones y los tiempos de procesamiento. Las recuperaciones a nivel laboratorio indican que la promoción de la actividad bacteriana es uno de los factores para acelerar el proceso de solubilización del cobre calcopiritico del concentrado. La actividad bacteriana se define como la capacidad de adaptación que tienen las bacterias en medios lixiviantes para elevar la velocidad de oxidación del ión ferroso y convertirlo en férrico y es el mecanismo para la lixiviación del sulfuro primario o calcopirita, el resultado de la interacción de las bacterias ferrooxidantes, el oxígeno y el control de ácido que mantienen un pH por debajo de 2.1. En ese sentido, el presente texto señala las pruebas de lixiviación de concentrados que incluyen estos últimos conceptos, con el objetivo de evaluar la factibilidad técnica y económica de obtener licores de cobre que puedan ser aprovechados utilizando la capacidad existente de extracción por solventes y electrodepositación de la planta LESDE Toquepala.

Sep 12, 2005

Experimental investigations were made into the decoppering of lead, tin, and bismuth using a technique which approximates on the small scale to industrial practice.Decoppering lead with sulphur alone in the absence of tin and silver did not proceed to low copper values. With a minimum of 0·02 per cent Ag or 0·10 per cent Sn, lead was decoppered to less than 0·01 per cent Cuby stirring with 0·2 per cent S over 10 min. Decoppering of tin or bismuth proceeded rapidly to very low levels in the absence of any "catalytic" impurities, at any rate in excess of those concentrations normally encountered in commercially pure tin or bismuth.

Jan 1, 1971

By Alton Gabriel

During the fall of 1940, J. R. Thoenen of the Mining Division, Bureau of Mines, accompanied by the senior author, surveyed the more important domestic alunite deposits. Although the study was designed primarily as an economic survey, samples from a number of the deposits were collected to investigate the beneficiation of the lower-grade material.

Jan 1, 1942