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By M. A. Trevits, A. Ozment

"According to the Office of Surface Mining Reclamation and Enforcement, Abandoned Mine Land Inventory System, in 2013 there were 98 underground mine fires in nine states. This is considered to be an underestimate for the actual number of fires nationwide. Many mine fires are started by people burning trash where the coal seam or an abandoned coal mine is close to the surface. Other fire ignition sources include lightning and forest fires. Once ignited, a coal mine fire can easily spread into the remaining coal pillars and mine entries. Once established, the fire creates its own ventilation system supporting further combustion by drawing air down into the workings through unsealed mine shafts, fractures and surface subsidence depressions. As the coal left in the workings from the past mining operations burns, the mine void can collapse, causing subsidence and creating dangerous voids, damaging overlying surface structures and roadways. The products of combustion include smoke and noxious fumes such as carbon monoxide gas. These products are released to the atmosphere through fractures that develop within the ground surface, killing vegetation and creating serious health hazards (Richmond, 2017).Abandoned mine fires, if left uncontrolled, can burn for years and, in fact, one of the most wellknown mine fires in the United States is the mine fire in the Borough of Centralia, PA, that began on May 27, 1962. Reportedly, officials decided to clean up the local landfill for the upcoming Memorial Day holiday by burning the garbage on the site. Unfortunately, the landfill was located on the site of an abandoned strip-pit mine on the edge of the Borough (Dekok, 2009). The strip pit had been left open after being excavated around 1935 and was approximately 23 m (75 ft) wide and 15 m (50 ft) deep. It is believed that the lack of a properly constructed noncombustible shale barrier in the strip pit enabled the fire to spread to adjacent carbonaceous refuse material and then to nearby coal mine workings (PA DEP, 2017). As time went on, the fire grew and spread under the Borough and directly affected the residents despite various efforts to extinguish the fire by the state and federal governments (Fig.1). In 1984, a voluntary program was begun to move residents from their homes. Many accepted buyout offers for their properties and moved elsewhere and after leaving, their homes were demolished. In 1992, the state used eminent domain to take control of all the property within the Borough. In 2013, after years of litigation, the eight remaining residents were allowed to stay for as long as they lived. Today, only a few buildings remain within the Borough (Centralia, PA, 2014). This fire has been burning for more than 55 years."

Jan 5, 2018

By Lynton B. Manssen

Introduction Net Present Value (NPV) techniques are becoming widely used in industry as a standard analytical tool in making capital budgeting decisions. However, NPV techniques are often misused in "common practice." A comparison was made between the use of NPV techniques in common practice and an Adjusted Net Present Value (ANPV) approach to capital budgeting in the financial analysis of a mining project. The comparison was made by applying both methods to a hypothetical copper project. The intent of the analysis is to provide an example for practitioners to follow when financially analyzing mining (or other) projects. To maintain the thrust of the analysis, the project has been evaluated as a stand alone, total project. No consideration has been made of the division of cash flows accruing to various owners over the life of the project. This omission will not affect the comparative nature of the analysis. This discussion assumes that the reader is familiar with present value as a concept and as a tool in capital budgeting. Finance theory has embraced NPV analysis as the correct way to evaluate capital budgeting alternatives. Many articles have been written expounding the virtues of NPV over other capital budgeting methods, such as Internal Rate of Return (IRR), Payback, Accounting Rate of Return, and others. It is not the purpose of this article to review all of the literature in this area; suffice it to say that in academic circles NPV concepts are accepted as the norm. A survey by Schall, Sundem, and Geijsbeck (1978) indicates that major US companies are finally following in academia's footsteps. Fifty-six percent of the companies responding to the survey use NPV techniques in their capital budgeting process. Further, some 86% of the companies surveyed use discounted cash flow methods (NPV or IRR) for capital budgeting decisions. This compares with a survey by Klammer (1972) that showed 57% of companies using both techniques, a considerable increase in seven years. With the increasing use of NPV techniques in industry, there are certain uses in common practice that can give misleading results. Five common errors in NPV analysis of large projects are: • No distinction is made between real and nominal cashflows. • The discount rate(s) used in the NPV analysis is not formally adjusted for risk. • There is no distinction of possible differences in the riskiness of different project cash flows; i.e., revenue vs. depreciation. • There is no recognition of the cash benefits to the project from interest tax shields (interest payments on the project's debt that are tax deductible). • There is no clear recognition of subsidies to the project from concessionary debt financing. No Distinction Between Real and Nominal Cash Flows Often, expected cash flows for a project are stated as a mixture of real (in constant dollars) and nominal (in current dollars) cash flows. For example, expected revenue cash flows may be stated in real terms and depreciation may be stated in nominal terms. If cash flows are added together to give an after tax cash flow, and this single cash stream is discounted, care must be taken to ensure that cash flows are consistently stated. All cash flows should either be stated in nominal terms or in real terms. In addition, the discount rate used must be stated in the same terms as the cash flows being discounted. Real cash flows must be discounted using real discount rates and nominal cash flows using nominal discount rates. Discount Rate Not Adjusted Numerous methods for obtaining discount rates are used in common practice. Schall and others

Jan 6, 1983

By S. K. Kawatra, H. J. Haselhuhn

"Thickening is used during two primary mineral processing operations: water removal and desliming. During water removal, the pulp density is increased through the injection of flocculants. These flocs settle and create a dense pulp while clarified water is removed through the overflow. During desliming, fine particles are removed through the overflow. Desliming can also be used as a mineral separation process known as selective flocculation-dispersion, where valuable minerals are flocculated and gangue minerals remain dispersed and exit through the overflow.There are many ways to analyze thickener performance on a laboratory scale, but these analyses often do not correlate well with full-scale performance. Some pilot-scale systems have been designed using a semicontinuous approach, but the amount of material required to perform their tests can make semicontinuous pilot thickeners impractical for most applications. This paper focuses on the design and optimization of a continuous pilot-scale deslime thickener that requires minimal material to operate. The design, optimization strategy, and an example study of reagent selection are demonstrated. IntroductionMany laboratory methods have been employed to size and optimize thickener performance. The most common of these include the Coe and Clevenger method and methods derived from the Kynch theory of sedimentation. The Coe and Clevenger method was developed in 1916 and was proven for slurries that do not require flocculation to settle. This method proposed that the settling rate of the pulp is only a function of the solids concentration. It is executed by creating slurries of several different concentrations of solids and performing bench-scale settling tests in graduated cylinders. For each concentration, a thickener unit area can be determined using the following equation (Coe and Clevenger, 1916; Laros, Slottee and Baczek, 2002):"

Jan 1, 2017

By P. G. Dempsey, J. R. Heberger, J. P. Pollard

During a mine disaster or emergency, underground air can quickly become contaminated. In these circumstances, all underground mine workers are taught to don breathable air supply units at the first sign of an emergency. However, no contemporary oxygen consumption data is available for the purposes of designing breathing air supply equipment specifically for mine escape. Further, it would be useful to quantify the oxygen requirements of breathing air supply users for various escape scenarios. To address this need, 14 participants crawled a distance of 305 m each while their breath-by-breath oxygen consumption measurements were taken. Using these data, linear regression models were developed to determine peak and average oxygen consumption rates as well as total oxygen consumption. These models can be used by manufacturers of breathing air supply equipment to aid in the design of devices that would be capable of producing sufficient on-demand oxygen to allow miners to perform self-escape.

Jan 1, 2015

By J. G. Mansanti

The metallurgical response of a deposit's various ore types usually has a strong impact on the flowsheet design of most mineral processing plants. This impacts the materials handling, equipment selection, capital and operating costs, and plant availability. Because of the rapid leaching characteristics of Chimney Creek ores a variation of the conventional gold plant, carbon columns and CIP was proposed. The proposal consisted of a washing stage which was installed between the typical leaching and CIP stages. The circuit was simulated in the lab and was modelled using a computer program to evaluate the metallurgical impact and the effect on the system's mass balances. Also, actual plant data was reviewed comparing the results that were achieved with the results that were expected.

Jan 1, 1988

By Paul Dean Proctor

The world's population by 2000 A. D. may approximate 6.5 billion and the United States' 304 million. South Asian population increases between 1970 and 2000 A. D. will be triple the projected population of North America. Such anticipated dramatic and probably traumatic increases in world population yield grave concern for the standard of living in the world and the United States. The people of the United States currently consume 32 percent of the world's energy and similarly large percentages of the world's mineral raw materials. With only 6 percent of the present world's population and slightly smaller percentage by 2000 A. D., much expanded world-wide production of energy and raw materials will be required to maintain even a standstill living standard. A minimal 2 percent increase per year in the standard of living in the United States and a 4 percent increase elsewhere in the world, beyond the demands of the estimated population increases, suggest the magnitude of the increased need for energy-mineral raw materials and the possible crises the world will face in these areas by 2000 A. D. Mineral engineers and scientists with broad educational backgrounds will be required in greatly increased numbers to help alleviate, and possibly avert, expected energy-mineral raw materials shortages of the next millenium. Explorationists, mineral engineers, commodity economists, environmentalists, city, county, state, and federal mineral materials planners and coordinators, and metallurgists will be among those most needed. AIME membership in the second century of the Institute's history will contribute directly to this personnel pool.

Jan 1, 1971

By John Duff Erickson

Determination of the final pit limits of an open pit copper mine is a problem that has far reaching effects on the life, profitability and operation of a mine. The solution to this problem requires that all of the significant variables affecting the final pit limits be considered together with corporate objectives as the guiding principle. This paper discusses the use of these variables and how they should be applied to plan the future of a mine. The objectives of a final pit plan; are determination of the extent and location of ore reserves, the allowable stripping to be accomplished to uncover the ore, the final pit surface intercept, final pit topography and the contained metal values in both ore and waste. The objectives of the plan must be consistent with corporate objectives as they pertain to profit, future investment in the mine, return on investment, alternative investments, conservation and perpetuation of the corporate entity. The subject will be treated in three parts: economic considerations, effect of leaching and pit design technique. At the outset, it is assumed; that the extent of and metal values in the mineralized area to be considered have been reasonably defined by development drilling and sampling.

Jan 1, 1968

By Louis C. Just, Grahan A. Mathieson

Low cost, greater operating flexibility, and relatively simple operation are just three of the reasons for using minicomputers in the mining industry. No less than a dozen US manufacturers have sold the new generation of minicomputers to mining operations in the US and the world. Many manufacturers produce several models of minicomputers, each with excellent calculating capabilities. Prices for these "mini-giants" range from about $10,000 for a basic system to over $300,000 for a very powerful, sophisticated system with numerous peripheral devices. While the acceptance of minicomputers by the mining sector has lagged behind their penetration into other businesses, mines with minicomputer capability-especially remote mine sites-have found applications in practically all areas of operations including standard payroll processing, mineral deposit modeling and planning, surveying/mapping, production reporting, and daily production scheduling. In fact, the only limit to the further application of minicomputers in mining is the user's imagination. There are some obstacles to the accelerated use of minicomputers in the mining sector: the limited amount of software available, limited information on site-specific uses, and limited interest in the mining market by manufacturers. The latter is especially significant in light of the fact that many manufacturers queried in a recent telephone survey did not compile statistics on locations of their units in mining. The general consensus is that mining sales represent less than 1% of the total market. Many manufacturers do believe that market dynamics will increase their future research and development for the mining industry. The minicomputer was introduced in 1968, when Digital Equipment Corp. of Maynard, MA, developed a small computing device-the PDP-8 minicomputer. It is important to note that since then, it has become increasingly difficult to precisely define a minicomputer (see box, page 1582). The mini has evolved to surpass the capabilities of many of the large computers (mainframes) of 1968, and some models rival the mainframes of today.

Jan 11, 1981

By L. Alan Weakly

Global warming is a political reality in the United States today. The actual impact of the continued utilization of fossil fuels is not known and is open to debate. However, the growing concern about the continued use of these fuels is problematic. There are technologies available to us today that would permit America to meet its future energy demand and not contribute to global warming. The inconvenient reality is that fossil fuels cannot completely be replaced with energy conservation and the use of wind, solar, hydroelectric, geothermal and nuclear energy. The connection between the greenhouse effect and global climate change was first identified by physicist John Tyndall in the 1860s. To prove the greenhouse hypothesis, Roger Revelle and his research team started measuring carbon dioxide concentrations in the earth?s atmosphere in the early 1960s (Becker, 2007). With the rising concern about global warming, scientists throughout the world have been obtaining surface and air temperature data. Scientists have also been comparing CO2 concentrations found in glaciers throughout the world with theorized annual temperatures. Data for both dates back 1,000 years. Armed with this data, many nations of the world and the United Nations Intergovernmental Panel on Climate Change (IPCC) have concluded that climate change is a reality. The IPCC also concluded that this climate change is the result of mankind?s consumption of fossil fuels and that catastrophic consequences will occur on a

Jan 1, 2008

Ceremonies for the induction of five mining industry pioneers into the National Mining Hall of Fame are scheduled for Saturday, Sept. 25, 2004 at the Las Vegas Hilton in Las Vegas, NV. The 17th Annual Mining Hall of Fame Induction banquet will begin with a reception at 6 p.m., followed by the dinner and program at 7 p.m. The five inductees are Georgius Agricola, David William Brunton, Herbert E. Goodman, David Ray Mitchell and Robert Peele. Georgius Agricola (1494-1555) wrote De ReMetallica, an original and valuable work that discussed everything known about mining during the first half of the 16th century. In De Re Metallica, Agricola reviewed practical means of finding ores, methods of surveying and mining, the assaying of ores, types and uses of mining machinery, smelting, mine administration and more. David William Brunton (1849-1927) is best know

Jan 1, 2004

By P. Asadollahi, M. Invernizzi

"This paper describes the innovative full-face conventional tunnel excavation technology, with its advantages in terms of savings and safety. The full-face approach has been developed throughout the experiences gained in tunnel construction. The innovative design approach is focused primarily on the deformation response of the ground acting first and foremost ahead of the face, which is analyzed, predicted and controlled by pre-confinement of the core. The advantage of this method is particularly evident in difficult grounds. This paper will present the outstanding benefits given by the adoption of the full-face approach in two projects, the “Sochi” and the “Visnove” tunnels. THEORY AND DESIGN ASPECTS OF THE FULL-FACE EXCAVATION The main challenges in tunnel and underground construction industry are gathering the design data from the ground that is being excavated and foreseeing the critical stage during construction, where the materials are in its most critical configuration. These challenges shall be addressed during excavation when the lining and the excavation disturbance have not yet reach the equilibrium. The in situ stresses in the ground are redistributed (forming an “arch-effect”) around the opening, with zones of increased stresses around the walls of the excavation (Figure 1). The distribution of the stresses can be close or far from the excavation profile, depending upon having a ground capable of withstanding the deviated stresses well or unable to withstand them, respectively. In the latter case, the ground will plasticize and deform in proportion to the volume of ground involved in the plasticization phenomenon. When the ground completely cannot withstand the stresses redistribution, it will cause the collapse of the excavation. While in the first case, the arch effect occurs naturally, in the second case, it does occur naturally only when the ground is stabilized properly. In the case of collapse, the arch-effect must be produced artificially operating on the ground prior excavation. The design should be based on the understanding of if and how the arch-effect can be mobilized during tunnel excavation and ensure that is formed by calibrating excavation and stabilization operations appropriately. The arch-effect is function of the medium that is being excavated, the action taken to excavate and the reaction expected following the excavation."

Jan 1, 2018

By Scott G. Britton

Until now, only the range of typical construction projects which are repeated over and over during the life of a coal mine have been discussed. This chapter looks at underground construction projects which occur only once or twice during the life of any given mine and are major construction projects in both time and cost. These projects usually require the services of an outside engineering and construction firm with hands- on experience in design installation. Because of this involvement with engineering and construction firms (EIC), the role of the construction engineer will change from one of actively de- signing and directing tasks to one of planning, inspection, and quality control. To reflect this role change in the discussions, the focus of this chapter will be changed to a broad overview of project participation. Of course, the projects under consideration in this chapter could easily fill more than one book on their design and installation. In addition, major construction projects are extremely site specific, requiring months of data collection about site geology, physical conditions, and potential excavation and construction requirements. Therefore, no attempt shall be made to discuss any detailed construction aspects as was done in earlier chapters. The purpose of this chapter is to present the fundamental concerns of a staff engineer or supervisor. This engineer does not make the decisions on choosing the EIC firm, but assists and interacts with their project team to accomplish the goals set forth by higher management. The construction topics to be reviewed fall into three main categories. The first category is highlighted by the installation of a main surge bin; the second is typified by the construction of an underground shop; and the third category encompasses special projects such as rotary dumps, crusher stations, and foremen's offices. These categories highlight the differences between degrees of mine responsibilities for project completion. The first topic is usually a turnkey project by an E/C firm for a given mine. The second topic represents the leading role of the mine in the project with a contractor as a support service or equipment supplier only. The third topic, special projects, is an example of a joint venture-between a contractor (leading partner) and mine management. These roles can change with any given project, but the changes in management responsibilities for the construction engineer can be nicely illustrated for the purposes of this text. The first step toward constructing major mine projects is to analyze the mine which influence their design. From the mine management standpoint, these parameters should reflect the role the mine will play in the project construction. In other words, what is the nature of the proposed mine environment and what are the material, labor, and time requirements needed to assist or direct the chosen engineering and construction firm? Answering these questions requires some basic project planning and cost estimation work. Here, only a general treatment is necessary, since detailed discussions of these topics will follow in Chapters 8 and 10. For those persons interested in the role of the EIC contractor, I suggest beginning by reviewing the article by Beall, "The Role of an Engineering and Construction Contractor," presented in the October 1980 issue of Mining Engineering magazine.

Jan 1, 1983

By Otis M. Clarke

The 34th Forum on the Geology of Industrial Minerals gave members a chance to see the geology of various stone and ore deposits displayed graphically in quarry walls and also provided an opportunity to hear and see first-rate papers and posters on the geology of industrial minerals. Also, some field trips passed through areas of spectacular scenery. As a bonus, participants saw scenic mines, some of which are "pretty as a picture." Watercolor paintings prove it. At the Oklahoma Forum, the writer displayed a number of paintings of mines and other landscapes seen during previous Forum trips. These paintings and this brief article are part of a crusade to prove that some mines and geologic vistas are scenic wonders and belong in our visual heritage. It is a plea to save some of our best geologic exposures for future geologists, tourists, and artists.

Jan 1, 1999

By Norman Miskelly

Substantial progress has been made over the last ten years in the development of uniform national and international standards covering the definition, estimation and public reporting of mineral resources and mineral reserves. Agreement between the major participating countries has been reached, which include the requirement that a Competent Person prepares and approves publication of mineral resources and reserves. Most national regulatory organizations have accepted the new standards and have included them in the rules that must be followed by mining companies operating under their jurisdiction. These developments are the result of a concerted effort on the part of professional societies, national regulatory agencies, international organizations, and many dedicated individuals. The historical development of these standards is summarized in this paper. Accepted definitions of mineral resources and mineral reserves are discussed, as well as the definition and role of the Competent Person. Additional effort is needed before the international standards are fully understood, accepted and followed by mining companies, regulatory agencies, the investment community and the general public. Steps being taken toward development of a Mineral Reserves International Reporting Code Template (International Template) that will be available for all countries to use in deriving their specific country reporting codes, are outlined

Jan 1, 2003

By W. M. Hart

Business Process Improvement (“BPI”) Change to Survive “It is not the strongest of species that survive, nor the most intelligent, but the one most responsive to change.” [Charles Darwin] “If you want to understand something, try to change it.” [Kurt Lewin, social scientist] Many companies have tried one or more process management initiatives. Each effort may help develop a culture that is more receptive to change. Executive Management needs to be unwavering in support of change with systems and structures, staffing, development of people, measures, with incentives and rewards. General Electric developed principles for quality change management that are necessary for effective, continuing Business Process Improvement (BPI). Change Acceleration Process (“CAP”) One of the tools General Electric developed has been used successfully by companies around the world in a wide variety of industries. This tool, named Change Acceleration Process (“CAP”), is designed to improve acceptance of change. Acceptance is the method by which the creative energies of the workforce can be fully tapped. Over time, every employee receives CAP training at least once, and in many instances three (3) or four (4) times, and will work on one or more High Performance Teams. Thus, BPI can achieve and maintain its goals. The CAP tool focuses on: • Leading Change • Creating a Shared Need • Shaping a Vision • Mobilizing Communication • Making Change Last • Monitoring Progress • Changing Systems and Structures

Jan 1, 2006

By J. E. Gebhardt, J. A. Herbst, K. Y. Lee

Benefits of proper control of reagent usage in flotation circuits are typically improved metallurgy and savings in reagent costs. Improved metallurgy can mean more consistent product quality, i.e., final concentrate grade, better recovery of product values from the feed, or higher plant throughput at existing target recovery, and grade values. Flotation performance is sensitive to a variety of process disturbances which occur in operating plants, such as changes in flow rate, percent solids, size distribution. flotability of mineral species, etc. A way to handle these variations is to fully understand the dynamic flotation responses to disturbances and to implement a suitable control strategy to compensate for these disturbances. Depending on the objectives of the control system, various types of control strategies are available which employ different levels of refinement to achieve the desired performance. Typically, variables such as collector and frother dosages and reagent addition points can be manipulated to affect the performance of the circuit. In the case of sulflde mineral flotation, manipulation of the process electrochemical potential, in flotation and in grinding, offers another degree of process control. Because of the complex and interactive nature of flotation process variables, optimized reagent control requires consideration of all, or at least the most important, interactive variables of the flotation circuit. Model- based optimizing control provides a framework to handle the complex and dynamic nature of flotation reagent process control.

Jan 1, 1994

By R. G. Darmody

Chemical problems associated with surface mining, such as acid generating materials, are important and well documented. However, reclamation research has shown that poor soil physical condition is the most limiting factor to successful row crop production on reclaimed mined land. Critical to success are selection of the best available soil materials used in soil construction and a material handling method that minimizes soil compaction. Excellent corn and soybean yields have been achieved on low strength soils both in high weather stress years as well as low stress years. Total crop failures have occurred on high strength soils in years of weather stress. Some deep tillage practices have been successful in improving compacted soils, but it is preferable to avoid compaction when the soil materials are handled. Soil strength measurements with a cone penetrometer have proven to be a useful tool in evaluating rooting media and reclamation practices. Research has shown that surface mining can be a short term land use that may be followed by productive farmland, if reclamation is done correctly.

Jan 1, 2002

By Gary B. Glass

Seventeen percent of US coal production now comes from the 19 surface coal mines in the Powder River Basin of northeastern Wyoming. The Powder River Coalfield, which coincides with this topographic and structural basin, is unique to the conterminous US, in that it contains an estimated 934.4 Gt (1.03 trillion st) of in-place coal resources. At least 13.2 Gt (14.6 billion st) is a compliant, strippable reserve base. In 1993, an estimated 162 Mt (179 million st), or 98% of the coal mined in this Wyoming coalfield, came from the thick - average 30.5 m (100 ft) - subbituminous, Wyodak coalbed, or from the Anderson and Canyon coals in the one mine where the Wyodak is split into two separate coalbeds. The other 2.7 Mt (3 million st) of coal mined in the Powder River Basin in 1993 came from the School, Badger, Monarch and Deitz No. 3 coalbeds. In this "world class" coalfield, there are at least 13 other persistent, 3 to 15 m (10 to 50 ft) thick, coalbeds as well as the Big George and Lake De Smet coalbeds, which are each 61 m (200 ft) or more thick in places. None of these latter 13 coals are mined at this time.

Jan 1, 1994

By J. R. Caylor

The Mine Safety and Health Administration (MSHA) advanced several initiatives last year to further protect miners' health. Regulatory efforts included the implementation of a Hazard Communication rule for all mines, work on the Single Sample rule for all coal mines, and the Plan Verification rule for underground coalmines. Development and application of new technologies are actively encouraged in preventing miners' hearing loss and respirable dust overexposures. MSHA's successful x-ray program for screening of black lung among coal miners completed its third year. Compliance Assistance efforts are focused on Best Practices, outreach, and technical support for operators' specific challenges.

Jan 1, 2003

By Patrick McElhinney, Jacob Carr, Bruce Whisner, Cory DeGennaro, Jingcheng Li

Since 2016, electromagnetic interference (EMI) of personal dust monitors (PDMs) with magnetic proximity detection systems (PDSs) has been observed in underground coal mines. The EMI causes the magnetic field measurements of a PDS to change, which, in turn, alters the calculated location of the miner relative to the machine. Any altered location calculation can potentially cause the PDS to fail to warn a worker who is at an unsafe distance from the machine, arousing a serious concern on safety hazard caused by EMI in underground mines. The search for EMI mitigation strategies led to the development and use of large shielding pouches and boxes to hold the entire PDM to reduce its magnetic emission. Research on these pouches and boxes found that although they were able to reduce the emitted radiation from the PDM, they also disturbed the magnetic field of the PDS, affecting its performance. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have focused on shielding internal PDM components rather than shielding the entire PDM. The PDM air pump motor is one of the PDM components that has been identified as a major source of electromagnetic radiation and has been selected for further study and tests. The measurements show that a small copper or aluminum foil enclosure can effectively reduce the magnetic emission of the motor by between 50 and 85% at 73 kHz. This study compares the test results of the air pump motor with various cost-effective shielding materials. The data provided in this paper can serve as a reference for shielding enclosure design of the PDM air pump motor to reduce its electromagnetic emission as one form of EMI mitigation strategy.