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By C. C. Hatch

As part of a general project to simulate a concentrator, the Brenda Mines Limited secondary crushing plant, located near Peachland, B. C., was sampled during the summer and winter of 1975 to develop a digital crushing plant simulator specific to the Brenda operation. The purpose of this simulator was to study the influence of manipulable process variables on important responses and to permit study of alternative circuit configurations if desired. This paper describes the simulation methodology employed and presents the results of a computer study of the secondary crushing plant (1).

Jan 1, 1979

By William K. Brown

Are the results of an exploration program worth the cost? This is a question I suspect many of you are familiar with and, theoretically at least, it is an easy question to answer. The answer, of course, lies in comparing the future earnings stream the program is expected to generate, to the present value of the cost of carrying it out. While historical costs can be determined without much difficulty, estimating the value of a future earnings stream involves all sorts of assumptions regarding future costs, metal prices, inflation rates and an appropriate discount factor; and in the context in which the question arises, requires additional assumptions about mineral deposits which have yet to be discovered. As a practical matter, this kind of approach isn't likely to produce a very convincing answer; certainly not one convincing enough to satisfy a skeptical audience; nor one likely to temper the illusions of recent converts to mineral exploration, who are convinced that if enough money is spent, profitable discoveries will inevitably follow. Within broad limits, however, I believe it is possible to analyze the costs and results of gold exploration in the U.S.A. over the past 20 odd years in a useful manner. And while such an analysis is imperfect, it will provide some insight into this fascinating subject.

Jan 1, 1983

By Danny Chan, Shahram Tafazoli, Nicholas Himmelman, Edmond Chow

"While wearable technology has been garnering attention in the consumer market, enterprise and industry have just begun exploring its potential applications. Since February 2014, Motion Metrics International has been working in collaboration with Vandrico Solutions Inc. to apply wearable technology to improve productivity and safety in the mining industry.This article discusses the value proposition of using wearable technology to deliver critical notifications in mining. The advantages and disadvantages of various form factors are explored. The challenges, both specific to mining and in general to wearable technology, are defined. Finally, the concept of MetricsGear, the first wearable technology platform developed for mining by Motion Metrics International in collaboration with Vandrico Solutions Inc., is described. MetricsGear is designed to notify the user with minimal distraction to keep the user focused on his or her primary task and aware of mission-critical events. This focus and awareness allows the user to work more efficiently and safely. The mining process consists of a series of intricate stages, where certain events or conditions in one stage can have a huge impact on other stages. The notification of these critical events or conditions is vital for ensuring the overall efficiency of the mining process. Critical notifications can be classified as two types: timecritical events and contextual information. Time-critical events are situations where a timely response from a responder can have a significant impact on seizing an opportunity or mitigating cost. Some human-computer interaction (HCI) experts classify notification types based on the interruption, reaction and comprehension (IRC) framework. Time-critical events are classified to have high interruption, high reaction and low comprehension due to their urgency. The responder should have just enough information to identify the crisis and react as soon as possible (Chow, 2014). For example, when a tooth is lost during shovel operation, it is necessary to recover the missing tooth before it jams the primary crusher. The consequence of missing this critical time period is a jammed crusher that can cause the mine to be out of production until the jammed tooth is extracted (Baumann, 2013). In this case, the responder only needs to see an image to confirm if the tooth is missing and information to identify which equipment and when the tooth went missing (Fig. 1)."

Jan 1, 2014

By Paul H. Rydlund

The wide use of bulk ANFO in surface coal mines is questionable in our energy conscious environment. At many locations, bulk ANFO is not the proper economic selection. Water conditions, energy requirements, waste and spillage, and vibration control are factors too often overlooked in the proper choice of blasting agents. Cost savings over 20% have been realized by converting bulk ANFO to packaged blasting agents. Future trends suggest greater concern for energy conservation in blasting will limit bulk ANFO applications and promote packaged products where quality can be maximized, waste and spillage eliminated, and water compatibility in wet areas assured.

Jan 1, 1980

By John F. M. Sims

Political issues and a glaring infrastructure deficiency have retarded the emergence of a strong mining component to the Alaskan economy in recent years. Barriers to orderly mineral development are slowly being removed attendant upon changing political circumstances. Infrastructure development, as an investment avenue as well as a responsibility of the State, is receiving much greater attention than in the past. Alaska of course has a rich and varied mining history going back to the 19th Century. This paper, however, focuses on the mining potential, not the mining heritage of the 49th State. The mining industry is emerging from a nadir in the economic cycle - times during which it was buffeted by unsympathetic administrations and confused and confounded by the protracted land status- conflicts prior to enactment; of the Alaska National Interest Lands Conservation Act (ANILCA) and other milestone legislation. Today Alaska's mining industry looks toward a bright and healthy future and, in the process, will become a very important and vital component of the State and national economy.

Jan 1, 1982

By W. J. D. Stone

Many of the common valuable minerals have a magnetic susceptibility which is sufficiently high to render them amenable to magnetic separation. In addition,, many minerals which form the unwanted constituents of an ore can be removed by magnetic means. Magnetic separation in general has suffered seriously from, the lack of a high intensity wet separator. It is only recently that such a separator has become available to the industry. Prior to this, high intensity magnetic separation has been limited to the use of the dry techniques. Since the introduction of the Jones Wet High Intensity Magnetic Separator, extensive test work has been conducted to investigate possible applications. From the investigations conducted and the discussions that have taken place in the industry, it is apparent that the important mineral characteristic of magnetic susceptibility is not receiving the attention that it deserves. Applications for high intensity wet separation are being found in areas hitherto not considered.

Jan 1, 1963

By Earl M. Frizzell

Investigation of mined land characteristics, evaluation of irrigation systems and evaluations by the mining industry determined that irrigation is a feasible method for aiding the revegetation of coal mined lands in the western arid and semi-arid regions (Sherman, et al. 1980). The various regions studied displayed a commonality of characteristics which enables, independent of the site or region, the recommendation of solid-set irrigation. Irrigation should be supplemental by complimenting natural precipitation and should be implemented on a temporary basis. For germination, the vegetation requires application of small amounts of water in a gentle, frequent, and timely manner. For the establishment phase of growth, moisture should be applied and stored in the soil either through pre-irrigation or deep irrigation.

Jan 1, 1985

By C. F. Giermak

Over a considerable period of time great interest has been shown in selective dry concentration of fine ferromagnetic particles, although it is only recently that new permanent magnetic materials have been made available to permit building of such permanent magnetic separators. It is well known that the conventional drum separator does' not efficiently separate fine materials. The centrifugal force on any drum acts in accordance with the particle size and gravity, which may beat varying magnitude-.opposite to the magnetic force, especially when the material is not closely sized. The Magnetic-Mechanical Separator (MMS) is designed for the concentration of fine, unsized magnetic materials where the percentage composition of magnetics to nonmagnetics, or the nature and texture of the materials, is such that its unique agitation and shake-out action with no centrifugal force provides greater efficiency than is obtainable by conventional magnetic separation equipment. This machine consists of a complete double belt conveyor unit with a premagnetizing Axial Pole Agitating Pulley at the feeding end of the lower conveyor belt and a special agitating concentrator magnet above the lower belt of the upper conveyor.

Jan 1, 1965

By Trevor R. Ellis

In August 2011, the Southern African Institute of Mining and Metallurgy (SAIMM) contacted mining institutes and related societies internationally to assess their interest in participating in coordination of the review of the South African Code for Mineral Valuation (SAMVAL) with reviews of other mineral valuation standards. The main mineral valuation standards are the CIMVal Standard of The Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the VALMIN Code of The Australasian Institute of Mining and Metallurgy (AusIMM), the SAMVAL Code, and the extractive industries? guidance note of the International Valuation Standards Council (IVSC), Valuation of Properties in the Extractive Industries, GN 14, designed for application within the full set of International Valuation Standards (IVSs). By January 2012, SAIMM had concluded that the level of respondent interest was adequate to organize a meeting. A meeting was scheduled for April 18, 2012 in Brisbane, Australia in conjunction with a VALMIN mineral valuation conference organized by the AusIMM. The stated purpose of the meeting was to develop an accord on terms of reference for pursuing harmonization of mineral asset valuation standards adopted by the participating mineral institutes. SME decided that, although it has not developed its own mineral valuation standard, it should participate in the Brisbane meeting and the harmonization process, as also did the American Institute of Minerals Appraisers (AIMA).

Jan 1, 2012

By Raymond E. Langen

Uranium exploration in the Powder River Basin of northeastern Wyoming has been intensive since 1966 and in 1968 produced significant discoveries of reduced uranium ore by Humble Oil & Refining Company and others. Substantial reserves have been established in the area. High-grade carnotite ore was discovered in 1951 near Pumpkin Buttes in the central part of the basin (Fig. 1). Other mineralized areas were soon established from Pumpkin Buttes south to Monument Hill and Box Creek. Total production from these shallow oxidized deposits in the lower Eocene Wasatch formation was small. The AEC reports total production of 520,000 tons of ore averaging 0.19% U3O8. The authors are indebted to many people within Humble Oil & Refining Company and Esso Production Research Company for their assistance and guidance. SUMMARY AND CONCLUSIONS The Highland ore deposit, discovered in 1968, is a large uranium occurrence located in the southern part of the Powder River Basin. Uranium mineralization consists of sooty, black uraninite and coffinite coating sand grains and is concentrated along the margins of Tertiary fluvial sandstones. Uranium was transported by oxidizing solutions roving through the buried sandstones and spreading into less permeable channel-edge sandstones to form typical rolls and tabular deposits. Unaltered sandstones are light gray to gray-buff where the sandstones have been oxidized, the colors are various shades of red, yellow, and yellowish brown. An Oligocene tuffaceous source for the uranium is proposed; however, leaching of the arkosic and tuffaceous host sediments may also have provided a source.

Jan 1, 1971

By David A. Greenhut

The Kubota surface melting system has been under development since 1975. It has found commercial application on the melting of municipal sludge, and ash from solid waste. The melted product has physical properties allowing its use as a substitute for aggregate in cement and asphaltic construction. This paper describes the surface melting system, its current use and anticipated future use.

Jan 1, 1991

By Qingming Feng, Jinhong Zhang

This study investigates the application of fly ash as a high-strength, water-resistant precast construction material through geopolymerization. The experimental results show that working conditions such as water content, sodium hydroxide (NaOH) concentration, curing temperature and curing time significantly affect the mechanical properties of the geopolymer matrix. Through optimization, compressive strength above 100 MPa was achieved, and the optimum working conditions were found to be NaOH concentration of 10 M, water content of approximately 14 to 15 percent, and curing at 90 °C in an oven for one day or at ambient condition for three weeks. Water-soaking tests show that the geopolymerization product has high water resistance without losing noticeable compressive strength even after one month of soaking time. The findings provide a novel method to apply fly ash as a high-strength, water-resistant precast construction material.

By James Humphrey

There is a natural resistance to change in any form. When it comes to implementing a game-changing technology like autonomous haulage on an operating mine site, the resistance can at times appear insurmountable. Whether based on real information or misguided preconceptions, it?s essential that we don?t underestimate the effort it will take to overcome this resistance, while clearly recognizing when it?s worth the effort. These realizations did not happen overnight for sites where autonomous haulage has been implemented. Nor did they happen overnight for manufacturers of autonomous mining equipment. Caterpillar, for example, began building toward autonomy more than 30 years ago and had a truck operating in the mid-1990s. Lessons learned during those early years led to the realization that there was much more to be learned ? not just about the machines themselves, but about the systems and knowledge that must be in place for a successful implementation. Working closely with customers, initiating real-life demonstrations on mine sites, having discussions with regulatory agencies and other stakeholders ? these and many other activities were necessary before autonomy could be fully and successfully launched. After decades of effort, Caterpillar?s first official commercial autonomous mine site went to work in 2011 in Farmington, NM.

By Khosrow Badiozamani

Operating mines in Wyoming and Montana, which are generally characterized by shallow overburden and thick coal seams, are faced with reclamation problems which are unique to this area. Unlike the eastern or midwestern mines, removal of thick coal seams and lack of sufficient overburden creates overburden deficiencies that require careful evaluation prior to mining to insure compliance with regulatory requirements. Computer models and computer graphics can assist in such evaluation where appropriate alternatives can be selected which satisfies both the regulatory requirements and minimizes cost. This paper presents one such model used in evaluation of backfill requirements for restoration of surface and ground water regimes, restoration of mined-out areas to the approximate original contour, and the blending of the mined-out areas to the surrounding topography.

Jan 1, 1981

By Earl Parker

The mining/mineral processing industry constantly faces the challenges of handling tons of material in a variety of processes such as crushing, milling, drying, belt transfer and loadout. These processes result in the production of high volumes of dust. A variety of dust detection and collection equipment is needed to properly manage these emissions to remain compliant with stringent air quality and safety requirements. Dust monitoring and bag leak detection can provide ways to reduce air pollutants, make work environments safer and remain compliant with requirements from the U.S. Environmental Protection Agency (EPA), U.S. Mine Safety and Health Administration (MSHA) and U.S. Occupational Safety and Health Administration (OSHA). There are several approaches to monitoring particulate emissions from dust collection equipment. These can include visual inspections, differential pressure gauges or bag leak detection systems. Bag leak detection and monitoring systems can be optical, light based or electrostatic/triboelectric. Recent developments have advanced the efficiency and reliability of electrostatic/triboelectric style monitors. New technological improvements have been developed that are based upon the principal of unifying dc (impaction) and ac (induction) signals and incorporating other proprietary circuit innovations. This higher signal resolution technology results in a more robust and stable measurement for detecting the presence of particulate in a dust collector emission duct or a flow process pipe.

By W. Z. Choi

In our previous work, a population balance model describing the simultaneous processes of size reduction and mineral liberation has been developed. The experimental verification of this model, however, has been limited to a binary mineral system containing only one composite particle class. When considering multiple classes of composite particles, the estimation of model parameters becomes much more difficult. In the present work, a procedure for estimating model parameters for a multiple composite class model has been developed. Emphasis is placed on the direct experimental determination of these parameters. The physical significance of the breakage rate function and the liberation function in characterizing the liberation process is also discussed.

Jan 1, 1987

By Stephen J. Swan

Feed-forward control (i.e. the forward flow of information in a control system ) is a simple and flexible approach to over-all control of a ball mill-rake classifier grinding circuit. The system described here uses mill power, feed rate, mill dilution water flow rate, and classifier dilution water flow rate only, to control mill load, throughput, mill solids, and classifier solids as well as classifier overflow grind. The mill load is controlled by a simple feed-back control loop, while mill solids and overflow grind are controlled within close limits by a unique non-linear feed-forward water control system. In effect the control follows a limited mathematical model of the grinding circuit. The configuration minimizes deviations in overflow grind due to changing ore conditions, but since it is open-loop, and the model is not complete, it is affected by changes in total ball charge and liner wear. These effects are fortunately gradual, and changes in the grind can usually be kept to within ± 1% of a target continuously for several days without adjustment. Control adjustments are made with feed-back from laboratory composites. This control system has won enthusiastic operator acceptance; it is easily started up and shut down; grind-outs have been eliminated along with flotation machine flooding and mill spills. Standard measurements and components are used throughout providing a trouble-free system design at a moderate cost.

Jan 1, 1970

By Georgene Renner, Chee Theng, William Gleason

"A walk through the exhibit hall or a glance at the technical programing that was offered at the 2019 SME Annual Conference & Expo and CMA 121st National Western Mining Conference in Denver, CO, Feb. 24-27 makes it evident that the mining industry is an innovative one that is on the cutting edge of technology. However, a glance at the nearly 6,700 attendees of the conference and it is also evident that while the industry is moving forward at a rapid pace in some areas, it is lagging behind in terms of diversity, both in gender and ethnicity.At Monday morning’s keynote session, Hannah Ubi, a millennial and a public speaker who joked that she is the proud owner of a sixth-place swimming trophy and a number of participation medals, addressed a full house that consisted of many men with gray hair or balding heads. The issue of an aging workforce that is rapidly being depleted by retirements is not a new one for the mining industry. In fact, it has been a concern for the industry for more than a decade. The central question has long been, “when the current senior-level people begin to retire, how do we replace them, and how do we fill the knowledge gap that is walking off into the sunset?” SME has been on the front lines in searching for solutions to the impending problem and, along with industry partners, has worked hard to develop programs that will address these issues. Among other efforts, the Society has developed a Ph.D. fellowship program to encourage people to remain in academia to teach the next generation and to help train the next generation to take over in the private sector.“The SME Foundation’s Ph.D. and Career Development Grant program is exceeding expectations at this point with two Ph.D. students graduating and taking a position in academia and two professors achieving tenure,” SME Executive Director Dave Kanagy said during the conference.The Society’s Minerals Education Coalition (MEC) has done its part to help educate future generations about the mining industry with initiatives like EngineerGirl, the Boy Scout Merit Badge and Move Mining, the Shark-Tank-style competition that was held on Monday with five finalists competing for the top prize (ME, April 2019, page 53)."

May 1, 2019

By Matthew Holden, Jason Emery, Matthew Benjamin, Peter Craig

Over the last 25 years, through adversity and a growing level of risk mitigation, Australian Longwall mines have been using higher and higher capacity cable bolts for secondary support. A recent survey revealed 85% of Australian longwall cable bolts are a 70 tonne capacity pre-tensioned hollow post groutable system. Mines avoiding pumping cementitious grouts are sometimes using pre-tensioned resin encapsulated solid cable bolts of over 90 tonne capacity. Results from various industry and University research has led to manufacturer's fine tuning the construction of their cable bolts. A review of this research explains how smooth wire construction is now dominant. Aggressive shear has also led to some mines using 8 tonnes pre-tension instead of the previous common 20 tonnes pre-tension. Lower pre-tension acceptance is now leading to a greater use of threaded cable bolt end fittings, these are tensioned to 8 tonne using the drill motor torque. A recent development is the TEX cable bolt, a slim line threaded end fitting that fits with the drill hole like a standard rock bolt. This cable is being installed at the coal face as primary support off bolter-miners. The laboratory and in-situ testing of the TEX cable is presented. In a bid to improve gateroad development rates and ground support in the last several years, a 100 tonne tensile capacity Goliath cable system was developed. The latest development in resin anchored solid cables is a 110 tonne capacity cable bolt, with laboratory and in-situ testing results presented.

Jun 25, 2024

By Víctor Vázquez, Guillermo Tiburcio, Martin Encinas, Jesús L. Valenzuela, Erick Montaño, Alejandro Valenzuela, José Parga

Merrill-Crowe is the primary process used for the concentration and purification of silver in a cyanide solution. The Langmuir Adsorption model for silver recovery in a cyanide solution was used for the study. The maximum adsorption capacity was 6.19 mmol/g for silver. This model properly adjusts the experimental results of the adsorption equilibrium with high correlation coefficients, which also favors the formation of a single layer of molecules adsorbed for the silver in the electrocoagulation- generated species. The thermodynamic parameters ΔG, ΔH, and ΔS were estimated, and it was found that the adsorption process is exothermic and spontaneous. For the kinetic study, the Lagergren second-order equation was used to study the adsorption speed. To characterize the solids coming from the electrocoagulation, X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) were used; the results of this study suggest that silver is present in aluminite, hydroniumjarosite, and alunogen.

Oct 30, 2021