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By Christopher R. Winter

Mining companies have sharpened their refocus on their tailings management strategies in recent years. Mining companies with tailings storage facilities that use the upstream construction method have been challenged to track the evolution of industry standards, assess risks, revise design, and communicate design revisions with regulators. While many aspects of best practices and industry standards have evolved in recent years as an attribute of continual improvement, the controlling standard in the design of many upstream dams is understanding the foundational strengths of hydraulically deposited tailings. Following best practices and industry standards, Hibbing Taconite Company managed by Cleveland-Cliffs, began the re-evaluation of foundation strengths underlying a system of upstream dams at the company’s iron ore mine tailings storage facility in northern Minnesota. Initial steps in the re-evaluation require reanalysis of design parameters and recommendations by the Engineer of Record to the Owner, which was followed by a series of meetings with the Technical Review Board to determine an initial path forward. Once a path forward and preliminary design parameters were determined, the Owner engaged with the State Dam Safety Engineer to discuss and seek approval of the plan. With continuous regulatory engagement throughout the process, further refinement of the design parameters for the hydraulically-placed tailings foundations underlying upstream dams began with field and lab geotechnical investigations. Following a review of risk assessments and trigger actions response plans, Hibbing Taconite revised its tailings storage facility operating plans and budget for the coming years. Based on the findings of the re-evaluation, reanalysis, and refinement of parameters, a paradigm shift was realized with the hydraulically placed tailings foundation strengths underlying the upstream system of dams. This paper explores the path that the Hibbing Taconite Company followed to understand the paradigm shift and construct downstream improvements. The plan involved tailings re-characterization, dam design revisions, operating plan reconciliation, budget revisions, wetland permitting, dam safety permit amendments, storm water prevention plans, borrow materials studies, new concrete decant structures and the pursuit to recognize and be consistent with industry standards.

Feb 1, 2024

By Dennis A. Long

Slip and fall accidents are a major cause of lost-time injuries associated with large mobile equipment in surface mines. An evaluation of the safety hazards associated with getting on and off large surface mining vehicles showed that most of the accidents occur at the point where personnel attempt to mount or dismount the machine at ground level. The major hazardous design conditions were identified as excessively flexible supports for lower steps or rungs, inappropriate ground-level-to-first-step distances, poor step designs, access designs that use vehicle components as steps or walkways, and inadequate hand- rail and guardrail designs, Additional hazards are introduced by the lack of proper maintenance of ladder hardware and the work practices of operators in carrying articles while mounting and dismounting the vehicle. This Bureau of Mines report describes the design and in-mine testing of improved access system for large mobile mining equipment.

Jan 1, 1984

By M P. Sandy, V Louchnikov, V Eremenko, M Orunesu, O Watson

"Surface support is a key component of most ground support systems which are applied as a means of reducing the risk of rockfall occurrence and maintaining serviceability of mine development. Surface support has two primary functions: distributing the applied load throughout the system by providing connection between rock bolts retaining smaller rocks that unravel between rock bolts.Confinement is also provided to the rock mass, which may increase its capacity to resist further degradation or loosening.Surface support has been routinely installed in most underground mines around the world for many years, yet the operators are still not always certain which type is best suited for deformable ground conditions. A number of factors need to be taken into consideration prior to selecting the type of surface support liner, such as its capacity, availability, practicality of installation, manual handling and loading conditions (static or dynamic) to ensure the system’s optimal performance in terms of safety and costs.This paper presents an overview of the surface support types currently used in underground mines in Australia. Shotcrete, weld mesh, high-tensile chainlink mesh, reinforced weld mesh and high energy absorption (HEA) mesh are discussed. A detailed description of each system is provided in terms of capacity, energy absorption, installation cycle and costs. The cost of each system has been normalised to the units of energy absorbed. The information presented in this paper can be used by underground operators as a reference guide when deciding on suitable surface support type for deformable ground conditions.CITATION:Louchnikov, V, Sandy, M P, Watson, O, Orunesu, M and Eremenko, V, 2014. An overview of surface rock support for deformable ground conditions, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 57–66 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

By Nicholas J. Grant

It is the purpose of this paper to examine a number of the recent developments in powder metallurgy, being most concerned with those which are yet to prove themselves rather than those which have achieved commercial maturity. Such developments include the production of very much coarser and very much finer powders, down to the near-micron size range. Also considered are activated sintering, direct powder rolling and extrusion (both hot and cold), brazing and welding, hydrides of reactive metals, oxide dispersion strengthened alloys and theoretical evaluations. Introduction T HERE surely can't be very much argument with the fact that powder metallurgy has made large advances on many fronts during the past ten or more years (1). These advances have taken place in raw materials, in processing, in product development and in a better understanding of many of the phenomena which occur in the various steps involved in powder metallurgy. It should be clear, in view of such growth, that it will not be possible to highlight all of the new developments in the present paper. Many of these developments,

Jan 1, 1965

By L. B. Pankratz

Enthalpies above 298° K were determined for AgCl to 1,400° K and for AgBr to 1,200° K by copper-block calorimetry. Before melting, both compounds showed an anomalous increase in enthalpy, an effect associated with lattice defect formation. Melting points and heats of fusion were determined to be AgCl, 730° K and 2,945 cal/mole; AgBr, 700° K and 2,030 cal/mole. The heat capacity of both melted substances decreased with increasing temperature over the entire liquid ranges investigated. Enthalpies above 298° K were tabulated at even temperatures along with derived entropy increments and heat capacity values. The results were combined with the known heats of formation and entropies at 29.8.15° K to obtain values of the heats and free energies of formation over the range 298.15° to 1,400° K for AgC1 and 298.15° to 1,200° K for AgBr.

Jan 1, 1970

By R. W. Waytulonis

This paper is an update of the activities of the U.S. Bureau of Mines, other government agencies, and the automotive and truck industry concerning diesel emission control. Enacted and proposed regulations from the U.S. Mine Safety and Health Administration (MSHA) and developments in diesel emission control are presented in terms of their impact on underground coal, metal, and nonmetal mines. Mine air quality regulations proposed by MSHA may require the underground mining industry to comply with new standards. Some mines may be required to take additional actions to meet new diesel particulate and lower nitrogen dioxide exposure standards; however, the mining industry is in a position to benefit from emission controls developed for the on-highway diesel engine market. The U.S. Environmental Protection Agency (EPA) has enacted regulations to reduce emissions from on-highway diesel trucks and buses. Engine manufacturers have responded by developing cleaner burning engines. Fuel producers have responded by providing cleaner burning reformulated diesel fuel, and exhaust aftertreatment devices have been developed to provide additional emissions reductions. Bureau research and development projects seek to determine the advantages of using modern engines and fuels, and to evaluate the efficacy of new exhaust control devices on mining machines. It appears that the diesel engine will continue to be a practical power source for use in confined environments because no other available power source is as mobile and efficient.

Jan 1, 1993

By Yong Hack Lee

Nonferrous smelting processes have been through a rapid transformation since the beginning of 1980. The copper smelting technology has changed from the conventional Blast Furnace process to the Flash Smelting and MIB process. In the field of lead smelting, the technology has changed from the Blast Furnace Smelting to the Direct Smelting such as QSL and KIVCET. In 1992, Onsan Refinery successfully commissioned Direct Smelting QSL technology for lead. The QSL could produce more than 160,000 ton per year of lead bullion from lead concentrate and various residues. Moreover, since the year 2000, the TSL (Top Submerged Lance) Technology utilizing the same Direct Smelting process has been successfully commissioned to treat lead concentrate as well as lead sulfate residue produced from a hydrometallurgical zinc plant. This paper presents and compares the energy flows of lead smelting processes such as a conventional process and the Direct Smelting Processes plotted on the Pb-O-S phase diagram. The oxygen potential diagram suggests how to control the oxygen potential in the fum ace. Also, it describes the recent operational experience in the TSL plant of Onsan Refinery with necessary mass balance of key elements.

Jan 1, 2003

By C. Watson Owings

"The mining Industry in the United States is becoming fully cognizant of the hazards of dust in underground mining as well as in surface plants. The dust problem in metal mines has been brought to focus through knowledge of the harmful effects of dust, especially silica, and through adoption of more or less stringent legislation classifying certain types of pneumoconiosis as occupational diseases. The coal-mining industry is aroused principally by the apparently great increase in the dust-explosion hazard resulting from the rapid growth of mechanized mining. The United States Department of the Interior, through the Safety. Division of the Bureau of Mines, has been requested repeatedly to recommend methods of allaying dust in both coal and metal mines. Methods adequate under hand-mining conditions fail to effect satisfactory reduction of dust in more rapid extraction with modern equipment. Studies of methods and equipment for allaying dust are being conducted in both metal and coal mines. Results of these studies are discussed, and indications of possible means of reducing dust concentrations are presented in the hope that the health and 'safety of men employed in the mining industry may be increasingly safeguarded.DUSTThe term ""dust"" is a common one, and yet the meaning is applied to widely different particle sizes. The general term means ""earth or other matter reduced to fine, dry, and powdery particles."" The root from which the word is derived means ""something that can be blown about by the wind."" As a result of tests on the explosibility of coal, the Federal Bureau of Mines has arbitrarily defined dust as being. ""that which will pass through a 20-mesh screen,"" based upon the fact that particles coarser than 20-mesh have little influence on the development of an explosion of Pittsburgh coal-bed dust. The study of dust, from a health standpoint, has given rise to still another definition of dust, namely,- according to Drinker3/, ""solid particles ranging in size from less than 1 micron to about 150 microns."" A micron is 1/25,400 inch, and 150 microns are approximately 1/1,700 inch. Atmospheric dust usually is considered as 10 microns or less, larger particles not being counted under the microscope in determination of dust concentrations."

Apr 1, 1942

By Philip S. Mathews

THE tremendous stimulus given to the mining industry by the gold and silver policy of the present administration has found the capital market for mines ill prepared to afford practical means of financing. Particularly has this been true of the host of abandoned high-cost producers and prospects which increased gold and silver prices have made potentially profitable. In a comparatively short time, experience has demonstrated abundantly that valuable properties have frequently failed to secure capital, while questionable properties have drawn to themselves and their promoters more of the public moneys than their prospects justify. Singularly enough the fault is usually attributable to faulty financing. Discussion and study of this problem are vital to the industry.

Jan 1, 1936

By AIME AIME

A COMMITTEE, representing a number of the larger oil companies in California, met in San Francisco on Nov. 12, 1919, for the purpose of discussing the depletion deductions to be allowed in computing the Federal income taxes under the Internal Revenue Act of 1918. It was the general sense of the committee that a system based on sound engineering principles should be formulated for estimating the value of oil properties, so that better and more uniform results might be obtained by the various companies in filing their returns with the' Bureau of Internal Revenue. A subcommittee, consisting of five petroleum engineers, was thereupon appointed to collect information and draft a report. The committee consisted of G. C. Gester, Carl H. Beal, J. H. G. Wolf, E. G. Gaylord, and E. D. Nolan; this report is the work of that subcommittee.

Jan 1, 1920

The Bureau of Mines is operated to assist in promoting economic development through increased efficiency in the mining, preparation, treatment, and utilization of mineral substances; to aid in conserving mineral resources through preventing waste; and to help the mining industry improve health conditions and increase safety. Accomplishment of those ends is sought through investigation of scientific, technologic, and economic problems of the, mineral industries and dissemination of resulting information. Building materials of mineral origin constitute an important product of mining, and the Bureau makes studies of these in the various fields mentioned. The following commodities come within this classification: Asbestos, anhydrite, asphalt, cement, clay and clay products, diatomite, dolomite, glass and mineral wool, granite, greenstone, gypsum, lightweight building materials, lime, limestone, magnesite, marble, sand, sand and gravel, sandstone, sand-lime brick, slate, soapstone, and trap rock.

Jan 1, 1937

By Robert G. Lundquist

This report summarizes all relevant findings and conclusions regarding capabillty of high-energy projectile impact to operate effectively in an open pit mining environment and to successfully handle secondary breakage and bench scaling problems. A silenced, aimable, mobile projectile launcher was designed and fabricated, utilizing a Government-furnished smooth-bore, 90 mm cannon. The silenced launcher was tested at the contractor's test site prior to shipment to ANAMAX Mining Company's Twin Buttes Mine near Tucson, Arizona. Demonstration tests were conducted at an inactive waste dump in the mine on 39 oversize boulders to determine the relationship between boulder size and projectile energy required for secondary breakage. The high energy projectile impact method (known by the acronym REAM -Rapid Excavation and Mining) was tested on an additional 23 boulders in the working mine and on 31 areas of potentially loose rock high on the pit walls. Most of the secondary breakage tests were successful and acceptable for open-pit mining purposes without producing large amounts of fly rock. Five of the 31 scaling tests were successful with one shot, but most of the remainder required two or more shots, and a few could not be dislodged because they were not as loose as they appeared to be, based on visual examination from a distance. Cost comparisons between the REAM method and conventional methods of secondary breakage and bench scaling are discussed. A film documentary, REAM--Mining Applications of High Energy Projectile Impact, has been produced by the contractor depicting the applications of the silenced cannon.

Jan 1, 1976

Bosworth, T. 0. The Mackenzie oilfield of northern Canada. Petroleum Times, vol. 5, Apr. 30, 1921, pp. 489-491. Jour. Inst. Petroleum Technologists, vol. 7, Oct., 1921, pp. 276-290; discussion, pp. 290-297. Gives location of the field, some of its geology, mode of occurrence and character of the oil. See also Oil Trade Jour., vol. 12, June, 1921, pp. 48-108. Canadian Min. Jour., vol. 42, May 27, 1921, pp. 420-422. Oil and Gas Jour., vol. 20, June 3, 1921, pp. 90-90. Petroleum World (London), vol. 18, June, 1921, pp. 233-2.64, 236-238, 240-241. Bull. Canadian Inst. min. and met., July, 1921, pp. 629-638. Mining and Metallurgy, Oct., 1921, pp. 47-48. Bureau of Foreign and Domestic Commerce. Resources of Balkan and Near Eastern countries. Commerce Repts., Oct. 24, 1921, pp. 488-489. Includes summary of the mineral resources of these countries, mentioning petroleum and allied substances in Roumania, Albania, Anatolia, Mesopotamia, Palestine, Arabia, Persia.

Jan 1, 1921

By Doris Hiam-Gálvez

El presente trabajo describe las últimas tecnologías que mejoran la minería en América Latina y la eficacia en el procesamiento del mineral. Así también se revisa el modo innovador de energía a través de la fundición de sales con energía solar, particularmente en regiones desérticas de América del Sur. Cada tecnología ofrece mejoras sustanciales en eficiencia, capital, y costos operativos y contribuye a la reducción el impactom ambiental de las operaciones mineras.

Feb 1, 2012

Jan 1, 1987

By D. B. Hyma

"The Raglan Ni/Cu property is located on the Ungava Peninsula in Northern Quebec, Canada, at a latitude of61°42' and a longitude of73°40', approximately 40 km southwest of Douglas Harbor. Geological reserves are estimated at 18 million tonnes, grading 3. 1 % nickel, 0.9% copper and smaller amounts of cobalt and platinum group metals.Extensive project development has defined the concentration process, concentrator sizing, tailings and environmental management required for this project.The grinding circuit selected is a fully autogenous primary grind, with pebble crushing and a pebble mill for secondary grinding to produce a product of 80% -70 microns for flotation.The flotation circuit is a simple circuit utilizing roughing, a regrind of rougher concentrate to 80% -20 microns, two stages of column cleaning with a cleaner scavenger bank on the column tails.Concentrate handling options were thoroughly reviewed because of the pyrophoric nature of the concentrate, remote site location and long distance to downstream processing. The preferred option, currently.is to dry the concentrate at Raglan to less than l % moisture and then pneumatically handle the powder.A detailed analysis of tailings placement options, suggests filtered tailings placement to be the preferable route for the Raglan site.INTRODUCTIONThe Raglan Project, as proposed by Falconbridge Limited, will develop extensive nickel-copper deposits in the Ungava Peninsula, Quebec, Canada. The project schedule and construction conditions in the project area are demanding. The Raglan mineral deposits have been the subject of numerous studies and evaluations over the last thirty years and the Phase I 1991 pre-feasibility document includes exploration information obtained in the 1989 and 1990 drilling seasons. This review concluded that an 800,000 tonnes of ore per year mining and concentrating complex located at Katinniq could produce 20,000 tonnes per year of nickel at competitive costs."

Jan 1, 1993

By A G. Sheard

Fire safety requirements inside tunnels have become more demanding as tunnel designers consider the impact of potentially larger fires. Tunnel ventilation equipment is required to clear hot gases in the event of a fire. This is vital to maintain smoke free escape routes for people trapped in the tunnel and to facilitate safe access for emergency services. As the fire becomes larger, the temperature of clearing hot gases increases. Traditionally, engineers have taken into consideration gas temperatures of 250°C when designing tunnels. Because of larger fires, engineers must now design equipment to clear hot gas up to 400°C.Increasing the temperature of hot gases to 400°C requires tunnel ventilation equipment that goes beyond historic limits. As temperature rises, material strength reduces, consequently mechanically constraining fan aerodynamic performance. Developing tunnel ventilation equipment suitable for clearing hot gases at 400°C requires a fan technology that is more typical of industrial turbomachinery. The standards EN 12101-3:2002 and ISO 21927-3:2006 defi ne the necessary design criteria and testing methodologies to verify that a range of tunnel ventilation equipment is capable of extracting hot gases.This paper describes the process by which the authors certified in accordance with EN 12101-3 and International Organization for Standardization (ISO) 21927-3 a range of powered ventilators suitable for clearing smoke and hot gases at 400°C for two hours. Proving the high temperature capability of the new range provided a challenge as a consequence of the large physical sizes and high motor powers involved. Additionally, the need to install vertically, as well as horizontally, imposed high thrust loads on motor bearings, further complicating both mechanical design and testing. The paper presents the methods by which the authors overcame these challenges.

Mar 8, 2011

By M. Louarrat, G. Enaime, A. Yaacoubi, A. Baçaoui, J. Blin

"The purpose of this study is to prepare a new activated carbon from olive stones for use in gold recovery by carbon-in-leach (CIL) and carbon-inpulp (CIP). The preparation method chosen was physical activation using steam. The effect of four process parameters: the residence time for carbonization, the activation temperature, the residence time for activation, and steam flow, were studied by the mean of response surface method (RSM) in order to optimize the yield, iodine index, and attrition characteristics. These two last responses were used as primary indicators of gold recovery capacity and mechanical strength. The results obtained show that optimal activated carbon can be prepared under the following conditions: a carbonization time of 157 minutes, activation at 921°C for 53 minutes, and a water vapour flow of 0.18 mL/min. This optimum carbon has an iodine value greater than 1100 mg/g and an attrition index in the order of 0.74%. These values reflect the quality of the precursor (olive stones) as a raw material for the development of an effective new activated carbon for the gold mining industry. IntroductionActivated carbon is an effective adsorbent widely used in industry due to its high surface area, well-developed reproducible microporous structure, and high degree of surface reactivity and adsorption capacity. World consumption of activated carbon is steadily increasing. It is primarily used in industrial wastewater and gas treatment and also for silver and gold recovery from cyanide solutions (Syna and Valix, 2003; Soleimani and Kaghazchi, 2008; Buah and Williams, 2010; Eddy et al., 2011). However, activated carbon is expensive and it needs to be regenerated after each adsorption cycle. In order to decrease the cost of manufacturing activated carbon, low-cost forest and agricultural wastes are considered promising new materials. In recent years considerable research has been reported on activated carbon from agricultural wastes, such as olive stones (Yavu et al., 2010), acorn shells (Sahin and Saka, 2013), peanut shells (Wu, Guo, and Fu, 2013), grape seeds (Jimenez-Cordero, 2014), coconut shells (Yalcin and Arol, 2002; Gratuito, 2008), palm shells (Sumathi, 2009), cherry stones (Jaramilloa, Gomez-Serrano, and A´lvareza, 2009), macadamia nut shells (Eddy, 2011), apricot stones (Soleimani and Kaghazchi, 2008), and bagass (Syna and Valix, 2003)."

Mar 1, 2019

By W. P. Yant

Publication of lists of the devices for giving respiratory protection which have been approved by the U. S. Bureau of Mines is made periodically for the purpose of aiding consumers in procuring equipment .374/ The last published list , approved to March 15 , 1935 , appeared as Information Circular 6845 with the same title as this article . The schedules of requirements and tests which the devices must meet in order to obtain approval are published 2/6/1/8/ by the Bureau of tests the devices must Mines and are available to the public . It is pertinent to mention that the preparation of a schedule of requirements for fresh-air supply devices of the types commonly known as positive -pressure respirators , airline respirators , sand- blast helmets , and hoods , has been practically completed and will soon be ready for release to the public .

Oct 1, 1936

By Marco Olper

Zinc bearing materials containing chlorides and fluorides of alkali metals, such as EAF dust, Waelz oxides, galvanizing ashes, zinc & brass foundry fumes and converter fumes are little attractive, both technically and economically for processing in ISF plant or in a conventional zinc sulphate electrolysis works. The Ezinexm Process allows for the recovery of high purity zinc in cathode form, from these materials, regenerating the leaching liquor. The process is based on a new electrochemical system which depolarizes the anode reaction with reduction of the cell voltage, compared with the traditional sulphate electrolysis method. The electrolyte, based on a chloroamrnino complex, allows for the recovery of other valued metals present in the zinc bearing materials such as lead, copper and silver, these being recovered as a metallic cement consequently improving the economics of the process.

Jan 1, 1994