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By L. A. Feldkamp, L. I. Davis, F. Yuan, G. V. Puskorius

Emerging technologies such as neural networks and fuzzy logic have many potential industrial applications in diagnostics, modeling, and control. In the automotive industry, applications can be divided into those that impact manufacturing processes and those that relate directly to the product. Though discussion often centers on neural networks deployed in hardware, their potential in the development of problem solutions (however deployed) could easily be of greater importance. Here we concentrate on the use of neural networks for modeling and control, using a simulation of vehicle active suspension as a concrete example.

Jan 1, 1993

By A. De Daio, D. W. Fuerstenau, P. C. Kapur

Because of its pronounced tendency to undergo visco-plastic flow, coal ground in the energy- efficient high-pressure roll mill invariably comes out as a briquetted product which must be disintegrated in a conventional type of grinding device such as the ball mill. The aggregates comprise comminuted coal particles that are apparently extensively cracked and weakened during passage of the coal through the high-pressure rolls. Their deaggregation in a ball mill in the second stage is accompanied by further grinding of the coal with a relatively small expenditure of energy. Thus in spite of energy dissipation in briquetting in the roll mill and in disintegrating the briquettes in the ball mill, significant energy savings are possible in the fine grinding of coal in a two-stage serial grinding mode, as compared to ball mill grinding alone. It has been determined that for the best results the energy invested in the two grinding stages must be apportioned in an optimal manner, the energy consumption in the ball milling step is comparable to, even in excess of, the energy spent in the high- pressure roll mill; and 20 to 50 percent energy savings might be possible in grinding coal to minus 200-mesh size by this two-step process, as compared to conventional milling.

Jan 1, 1995

By Gordon R. Wicker, Willem P. C. Duyvesteyn, Robert E. Doane

A versatile acid leach process has been developed which is applicable to a broad range of oxide nickel ores. Inherent in this process are high recoveries of nickel and cobalt, as well as a relatively low energy consumption. These features extend the range of economic exploitation of laterite deposits to low grade limonites and to garnieritic ores not suitable for pyrometallurgical processing. Particular advantages can be realized in treating orebodies containing both limonite and garnierite and ores containing significant amounts of cobalt.

Jan 1, 1979

By D. Leppert

Large deposits of natural zeolites may provide cost-effective alternatives for treatment of soil and water contaminated ) with heavy metals and radionuclides. Research on the Bikini atoll demonstrated that addition of clinoptilolite to the soil significantly reduces cesium uptake by plants. Re- search on the potential use of zeolites in soils at Bunker Hill, ID indicated only minor benefits at very high contamination levels vs. US Bureau of Mines (USBM) work on the use of zeolites for treatment of mine waste waters emphasized problems with natural waters that previous studies have not addressed. High levels of competing calcium in natural waters significantly decrease the effectiveness of zeolites for heavy metal sorption and may limit the usefulness in these applications.

Jan 1, 1991

By Anthony Harding, Rodolfo D. Aradas, Juan M. Fernandez, Darío Tsingas

"The adoption of tunneled combined sewerage interceptors and outfalls leads to design linings which are often subject to internal pressures that are larger than the external pressures, resulting in significant tension loads. The need to meet stringent durability conditions for the normal design life of 100 years often drives client specifications to require a double pass solution with a cast in situ secondary concrete lining. However, improvements in concrete technology and the need to seek efficiency in terms of time and costs, have driven designers to consider single pass segmental linings. The Riachuelo Sanitation project in Buenos Aires is subject to these constraints both upstream and downstream of a sewage treatment plant. This paper describes how the challenges of up to 2 bar pressure differential have been addressed by careful analysis of soil structure interaction to ensure that the full benefit of external ground pressure is realized, resulting in a more optimal design for the constructor both in terms of cost and time. INTRODUCTION The construction of long sewerage interceptors and outfalls is becoming an increasingly common piece of infrastructure for modern urban cities facing a large water front and estuarine conditions, which are under a significant environmental burden imposed by decades of sustained growth. Such works intercept most of the distributed sewage discharges to then divert them to a central treatment point from which it will be finally diffused via an outfall into a water body capable to accept these discharges under acceptable environmental conditions. Depending on the magnitude of the sewage load to be handled, the configuration of the urban environment and the conditions of the receiving water body, both in terms of oceanography forces and seabed conditions, these schemes will vary in length, conveyance capacity and design and construction requirements. When conditions permit, the current trend is the execution of long outfalls using flexible solutions (such as the use of HDPE pipes) which usually require some form of concrete ballasted weights to resist off shore dynamic forces when directly laid over the sea bed. However, this concept faces limitations when the conveyance requirements indicate the need for large diameters (typically above 3000 m) and also when the outfall needs to avoid deep features off shore such as navigation channels. When this occurs, tunneling, particularly segmentally lined tunnel constructed by TBM emerges as the most feasible approach for large diameter, long deep outfalls. The operating conditions often result in internal pressures that are larger than the external pressures, resulting in significant tension loads in the lining. The need to meet stringent durability conditions for the normal design life of 100 years often drives client specifications to require a double pass solution with a cast in situ secondary concrete lining."

Jan 1, 2016

By Steve Wirch, Robert Jankowski

The issue of dust control in underground coal mines has been extensively studied by both government and industry. This research work has resulted in many techniques which control the dust or help miners avoid it. Control techniques either prevent the dust from becoming airborne or cleanse the air before it can be inhaled. Avoidance measures minimize the exposure of miners to the airborne dust by blowing the dust away from work areas or making it unnecessary for a miner to occupy a dusty region. One of several successful dust control measures in continuous miner sections is the use of a machine mounted scrubber which cleanses the air and helps to prevent the contaminated air from reaching areas frequented by mine personnel. Research on the application of scrubbers on longwall shearers began in the 1970s and continued into the 1980s. The most successful projects showed only moderate improvement when a scrubber system was mounted on a longwall shearer, and the less successful projects actually increased worker dust levels. There are many reasons that scrubbers have not been successfully applied on longwalls. The most significant of these is that longwalls have across the face ventilation and generally have high face air flows. Scrubbers tend to work best when they are the primary cause of ventilation. Therefore, their capture efficiencies on longwalls tend to suffer because of the exposure of the drums to the primary airflow. Other reasons scrubbers have not been implemented on longwall s include the successful application of an excellent water spray system, effective cutting techniques, and dispersion of dust sources. These techniques can help control drum generated dust, increase production, and limit the relative effectiveness of a scrubber.

Jan 1, 1995

By R. Hiebert, M. Canty, S. Beckman

An innovative biological process is described for the treatment of cyanide-, metals- and nitrate-contaminated mine process water. The technology was tested for its ability to detoxify cyanide and nitrate and to immobilize metals in wastewater from agitation cyanide leaching. A pilot-scale demonstration is described in which a pilot plant was constructed to demonstrate the technology on a mine process-waste stream at a mine in Nevada. The demonstration was performed jointly under the Mine Waste Technology Program (MWTP), funded by the US Environmental Protection Agency (EPA) and jointly administered by the US De¬partment of Energy's (DOE) Western Environmental Technology Office (WETO) under Interagency Agree¬ment Number DW89938513-01-0. The Superfund Innovative Technology Evaluation (SITE) demonstration program was also involved in the project. MSE Technology Applications Inc. (MSE), Butte, MT, was the contractor responsible for conducting the project, and Pintail Systems Inc., Aurora, CO, was the technology provider. The pilot-scale unit was field-tested at Echo Bay's McCoy/Cove Mine southwest of Battle Mountain, NV. The biotreatment process was considered successful in destroying cyanide in the mine process water. The process was also determined to be effective in removing metals. The pH was consistently neutralized and nitrates were successfully removed from the mine process water. From the results of these pilot-scale tests, it was concluded that the biotreatment process potentially of¬fers an innovative, cost-effective alternative for the treatment of mining wastewaters.

Jan 1, 2000

Many organisations, including those in the resources industry have Board-level endorsed principles on sustainability. A key challenge, however, is how to systematically integrate these high-level principles into the design and operation of mineral processing plants. In an effort to meet this challenge the Sustainable Operations framework, called SUSOP®, was conceived and developed through the Corporative Research Centre for Sustainable Resource Processing (CSRP) in Australia. Somewhat analogous to HAZOP (Hazard and Operability Studies) which is well entrenched in the resources industry, the key aim of SUSOP® is to produce a holistic, systematic and rigorous methodology for identifying and assessing sustainability opportunities and risks. This paper argues the need for such a sustainability framework, presents the key elements of SUSOP®, highlights how case studies enhanced its development and articulates the reasons why such a framework will have growing importance into the future.

Jan 1, 2011

By M. Ghoreychi, M. Fauueau, P. Lebitou, P. Berest

A brief study of the history of gas caverns in salt formations enables us to consider creep mechanism in a cavity as a phenomenon of dissymmetrical deformation. Among different parameters affecting such a phenomenon, gravity forces, especially in large caverns, seem to be responsible for important bottom heaves as compared to roof releases. This fact is demonstrated here by means of certain theoretical considerations concerning elasto-viscoplastic constitutive laws relevant to rocksalt rheological behavior.

Jan 1, 1986

By R. M. Carland, F. F. Aplan

Six natural zeolites were evaluated for their ability to selectively remove heavy metal cations from solution. Ion selectivity was found to be Pb+2>Zn+2>Ni+2 and Cu+2>Co+2 from their respective solutions. The presence of K+, Ca+2 and Mg+2 in the actual waters to be used may seriously interfere with the ion exchange and elution of cations from zeolites. Zeolites were found not to be effective in removing precious metals from their cyanide solutions.

Jan 1, 1995

Passive seismic monitoring is a useful tool for measuring wave propagation in rock mass in deep underground mining. About 20000 mining ? induced seismic events of a hard rock mine, are identified and investigated. The travel times of source-receiver pairs allow us to demonstrate temporal change in velocity. It was found that the average P wave velocity is about 6000 m/s in the mining regions. Velocity investigations on the data during about three months around the main shocks show a significant decrease of the average seismic wave velocity after the main shocks. The sudden drop of average velocity change after the main shocks implies the creation of new fractures in the rock mass due to the main shocks. Afterward, the average velocity increased to a normal level after a time duration of several days. A reasonable explanation for the post seismic velocity increase is that opened cracks begin to close due to crack healing.

Feb 23, 2014

By F. M. Doyle, J. P. Dwyer

Introduction The mining industry has a poor public image. It is often perceived as a despoiler of the landscape and a polluter of the environment, and there is little recognition of societal needs for the raw materials and fuels that this industry produces. There are many reasons for this poor image, but an important one is that a substantial number of mining operations have caused significant damage to the environment. Many of these operations, particularly those that now are abandoned, continue to have an adverse impact, principally in the form of water pollution.1 In some cases, the damage caused by this pollution extends well beyond the immediate region around the mine. Chemical contamination of ground and surface waters can, and does, occur in nature when these waters flow through or over undisturbed, mineralized rock masses. However, the problem is greatly exacerbated by mining because the mining activities increase, by several orders of magnitude, the permeability and the surface area of rock that can be contacted by percolating water. Water flowing through either the mine workings or the waste rock dumps becomes contaminated. Pollution can also arise if leachate from tailings ponds enters either groundwater or surface waters. This leachate may contain chemicals used in processing the ore. The magnitude of the threat posed by mining wastes depends on the type of minerals in the deposit, and on the chemicals used to process the ore. The magnitude of the threat also depends on two other, site-specific factors. One is the volume of water flowing into the mine and through the dumps, which depends on rainfall patterns, topography, and whether the mine workings are surface or underground. The other is the proximity of the pollution source to groundwater or surface waters, which depends on both the climate and geology. These factors influence the concentration and the quantity of polluted water forming and reaching the receiving water. Mining activities present a potential problem of enormous scale. Vast amounts of rock are mined each year2 and, as noted above, substantial problems have arisen at some mine sites. These problems are usually exceedingly costly to address, and it is imperative that these mistakes not be repeated. There are indications that we can accomplish this goal; we now better understand the processes that cause pollution and have methods to prevent or contain it. In addition, in the past few decades society has started to recognize the need for all industries to operate in a manner that maximizes the health and safety of workers and the public and minimizes adverse environmental impacts. A variety of recently enacted federal and state laws regulating public health and environmental hazards reflect the increasing concern over these issues. Many statutes, such as the federal Clean Air Act and the Clean Water Act, encompass activities undertaken by the mining industry. Other laws, such as the Surface Mining Control and Reclamation Act, have been written to regulate specific hazards posed by this industry. At the present time, the federal government. through the Environmental Protection Agency (EPA), and several state governments, are preparing new regulations specifically tailored to control the disposal of mining wastes. Given the magnitude of the potential environmental and health risks posed by disposal of mining wastes and the regulatory costs to the mining industry (both of which are due to the tremendous volume of waste generated), it is especially important that regulators have a good understanding of the different types of mining wastes and the risks they are likely to pose in various geographic and climatic circumstances. Only then can a regulatory program be designed with suitable procedures and substantive criteria to protect the environment and ensure compliance, while avoiding unnecessary or wasteful expenditures. California has long enjoyed a large, active mining industry. Today it produces a wide range of mineral commodities. The revenue from production of non-fuel minerals in California ($2.85 billion in 1988) greatly exceeds that of any other state. About a third of this revenue is from the production of inert sand, gravel and crushed stone. However, the remainder is from the production of a wide range of materials. These include boron minerals, rare earths, asbestos, talc and pyrophyllite, and gold. In earlier decades, an even broader range of minerals was produced, including mercury, copper, lead, zinc, and barite. There are acute environmental problems at some of these early mine sites. Because in 1987 the state of California was engaged in a revision of its regulations for mining waste disposal, the legislature commissioned a study by researchers at the University of California at Berkeley to investigate and review: the magnitude of the problem posed by these wastes, • the best feasible control measures available for waste management and disposal, • the problems of abatement and cleanup at so-called "problem" mine sites, • the current regulations imposed on mining waste disposal by various federal, state, and local agencies and the effectiveness of these regulations. This paper summarizes the principal findings from this study (Mining Waste Study, 1988). The lessons from this investigation are likely to be of general interest because of the diversity of mineral products produced, and the wide range of geographic and climatic conditions encountered. The acute problems seen at some of the older mines are typical of the western United States, and teach useful lessons on strategies that should be implemented at new mines to prevent recurrences of these problems.

Jan 1, 1992

By Mengxiong Guo, Xuxin Shao, Yong Bao

In the paper, the adsorption properties of dissolved ions on the surface of collophane and dolomite are studied using zeta potential measurement, ESCA and UV adsorption spectrum both in distilled water and in the supernatant of each other. The effect of dissolved ions on the flotation separation of collophane and dolomite under SCO depressant and oleate is discussed on the basis of above analyses.

Jan 1, 1993

By Wenhua Wan, Jan M. Mutmansky

Many concerns have been expressed worldwide regarding the use of diesel equipment in underground mines due to the potential health risks associated with diesel particulate matter (DPM). In assessing the risk to the health of miners and designing control strategies for DPM, it is important to know the concentration of DPM in the working areas of a mine. In some mines, significant stratification occurs due to the characteristics of the diesel exhaust, affecting exposure and the ability to measure DPM concentrations accurately. This study outlines some of the concentration profile data obtained during sampling at three mines where diesels were employed. Mine #1 (a gold mine) employed large openings in which a diesel-powered roof bolter was used. Mines #2 and #3 are both room-and-pillar operations with varying conditions. Mine #2 is an experimental mine where two stationary diesels were utilized for sampling purposes, while Mine #3 is a traditional evaporite operation using two mobile diesel vehicles for section haulage. These field studies indicated that some level of stratification occurred in all the mines, but the stratification was not as pronounced in the case of Mine #2 due to the complex pattern of exhaust emissions generated by the vehicles. The stratification seemed to depend on the distance from the vehicle, the mine air velocity, whether the vehicles were moving or stationary, and whether the exhaust was diluted by equipment design features. The concentration of DPM was generally higher at samplers located near the roof and lower at samplers located near the floor. However, this was not found in all cases. This paper provides conclusions on how knowledge of stratification patterns can be utilized in sampling and control of DPM in mine atmospheres.

Jan 1, 1997

By John D. Grothe

Laboratory experiment as a basis of commercial plant design has been the subject of much analysis and thought and on which a large number of articles and papers have been published. We would be forced to choose between an unduly brief exposition if we wanted to cover it completely, or no exposition at all. We must therefore concentrate upon the essentials without ignoring at the same time too many of the qualifying factors which, by the choice of what we want to examine, may become side issues. In doing so, we do not imply that these side issues are therefore any the less important. In every case, what is said here applies with almost equal force to the pilot plant which may be necessary as it does to the commercial plant. In discussing a recent paper by Derek C. Shelton on the Santa. Barbara Mill in Chihuahua at a meeting of the Inst. of Mining & Metallurgy (London), D. J. Ottley said on the matter of relating laboratory results and small scale tests to full scale plant results that he would like' to draw the attention of members to the great difficulty of scaling up mineral dressing plants and processes. He felt that this was an important yet neglected subject which merited considerable fundamental scientific attention from mineral dressers and plant design engineers in particular. How much of this fundamental scientific attention has, as a matter of fact, been accorded to the subject, mainly by our sister profession, Chemical Engineering. The close similarity to chemical engineering problems that we meet, particularly in hydrometallurgical operations, suggests that Chemical Engineering publications offer a rich source of information and discussions of methods useful to us. We have only to think of pressure leaching, ion exchange, liquid-liquid extraction, precipitation and so on, all problems in chemical engineering unit processes or of the new Freeport Sulphur Nickel plant in Cuba or the Sherritt Gordon plant and many others.

Jan 1, 1960

By Harry J. Fitzgerald

During World War II mining machinery manufacturers were limited in the development of their product improvement programs. Following the war, however, the ideas and intentions of both the users and manufacturers of mining equipment became evident. The Coal Industry launched a series of events which indicated their determination to rise to the economic challenge of developing profitable machines which would eliminate the out-dated and back-breaking methods of mining previously used. Two major technological advances were developed as a result of the ambitious goals forecast by the Coal Industry: 1. Coal mining was going "off-track" and concentrated mining operations were to follow in rapid succession. 2. Carbide tools provided the remaining missing contribution to another technological breakthrough....Continuous Mining. Little did the inventors realize the significance of the misnomer they created because twenty-five years later the industry is still striving to secure the results implied by the meaning of the word...."Continuous". Nevertheless, all major manufacturers embarked on programs in an attempt to compete for recognition in this new mechanized-mining endeavor Eventually in 1950 there were three types of boring machines and two types of ripping machines being manufactured. Mining Speed was the desired goal.

Jan 1, 1970

By J. Kretschmann, O. Drusche, S. Krause

Mining companies are caught between the growing international relevance of ESG (Environmental, Social and Governance) investments and the need to secure their “social license to operate” by considering the needs of their stakeholders. In the search for sustainable business models, the concept of the circular economy (CE) is gaining momentum among practitioners and scholars, as it enables the creation of shared value and thus strengthens the trust of investors and stakeholder relationships. However, there is a lack of a sectorspecific CE framework providing guidance to decision-makers in evaluating promising activities. A gap, which this contribution aims to address.

Mar 2, 2022

By Thomas W. Camm

A WINDOWS-based object-oriented expert system for prefeasibility evaluation of hard rock mines is being developed at the Western Field Operations Center (WFOC) of the Bureau of Mines. Designed for use with the Bureau's Cost Estimating System (CES), this expert system assists an evaluator in choosing an underground mining method, and the related design parameters. The system provides the engineering and design guidelines necessary for an evaluator to perform a prefeasibility type cost estimate.

Jan 1, 1992

By Robert L. Bates

The field of industrial minerals and rocks includes such a wide diversity of materials and occurrences that communication is essential to foster a sense of "belonging? among geologists and other professionals. Besides, exchange of ideas and information is essential in meeting the needs of an ever-expanding world economy. A survey of the field shows to what an extent such communication--especially in the form of conferences and their proceedings--has increased during the past 25 years.

Jan 1, 1995

By T. Brady, J. Johnson, J. Whyatt, B. Pariseau, M. Stahl

An elastic-viscoplastic material model allows for time- dependent rock mass motion in proportion to excess stress above the elastic limit. The model produces rounded stair-step curves of displacement vs. time that are similar to those obtained from recent borehole extensometer measurements made in the central portion of the Ross Shaft pillar at the Homestake mine. The work in progress, including two- and three-dimensional finite element analyses using the UTAH2/3 codes, indicates that the model is a step towards more realistic safety and stability analysis, but that inclusion of rock mass damage may be desirable.

Jan 1, 2000