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By James L. Weeks

Introduction This paper attempts to summarize some of the major criticisms of drug testing. Eight problems with drug testing are discussed. These are: • It does not measure something employers have a reasonable need to know, • It is a distortion of priorities, • Drug use is not known to be associated with increased risk of occupational injuries, • Drug testing is proposed as a dangerously simplistic solution to poorly conceived problems, • In the absence of safeguards, it is unacceptably inaccurate, • In the absence of treatment commitments and confidentiality protection for persons dependent on drugs, it is an unethical practice of medicine, • Drug testing is an invasion of privacy, and • It will have a negative effect on treatment of persons with drug or alcohol dependencies. Employers' need to know It does not measure something employers have a reasonable need to know. It is reasonable for employers and fellow workers to want to know if workers are functionally impaired (intoxicated) while on the job. Drug testing does not measure impairment. It measures the concentration of drug metabolities in urine or blood. Unlike measurements of blood alcohol concentration (BAC), drug metabolites are not correlated with impairment or intoxication. They indicate only drug use in the one to two weeks before a urine sample. And, in some instances, they indicate chronic use. Impairment caused by drug use, on the other hand, occurs immediately and declines rapidly within hours. Drug metabolites may linger for days afterwards. Drug metabolite concentrations in urine are a function of (Morgan, 1984; Schartz and Hawks, 1985; MMWR, 1983): • the amount and purity of drug consumed before taking the test, • when the drug was consumed, • whether the person was a chronic user, in which case a certain amount of drug metabolites would be stored in body fat and slowly released, • the person's metabolic rate, and • for metabolites in urine, any dilution effects of urine. Only the first two factors has

Jan 11, 1987

By Neville Slade, Doug Shumway, Dayan Anderson, Joe Siefke, Curtis James

The Mojave Desert is a particularly fragile ecosystem that faces several significant impacts. These include rapid housing development, overdrafted water supplies and loss of wildlife habitat — all a result of mining, industrial activity and urban sprawl. During the past three years, a diverse group of educators, natural resource managers and business leaders was assembled under the auspices of a local community college. This group’s goal was to provide unique natural resource education opportunities for the region.

Jan 1, 2005

By V. Izaxon

Current practice in mining frozen, underground placers is to support the mine openings by leaving remnant pillars, which are kept frozen to maintain their stability. These pillars may be partially extracted depending on mining conditions, but this practice may be risky, and roof falls are common. Instead of allowing the mined-out areas to cave, the extracted entries could be filled with waste material, which would then be frozen, using cold ventilation air. A finite difference model for analyzing the effects of various parameters on the freezing of backfill in underground mines in the Arctic has been developed and tested. The model also accounts for properties unique to a frozen rock mass, including those that change with temperature. Examination of the characteristics of ice-cemented mining waste materials as backfill indicates that with proper engineering control, a backfill system can be designed for use in production mines. The system will allow increased extraction ratio while maintaining the stability of underground openings with minimum heat impact on the surroundings. These simulated results establish the relationships among the strength, the temperature, and the freezing characteristics of a given material. When coupled with site observations these relationships will facilitate the optimal design of ore pillar recovery methods.

Jan 1, 2004

By Yang Ge, Yuzhu Pan, Mansheng Chu, Jue Tang, Cong Feng, Lihua Gao, Zhenggen Liu

The low-grade nickel laterite ore used in this study was successfully upgraded through selective reduction by industrialized rotary kilns followed by magnetic separation. The results indicated that both iron metallization extent and nickel metallization extent showed obvious linear correlation. In addition, rational roasting temperature and prolonged grinding time could enhance the overall fineness level of reduced laterite nickel ore. The moderate roasting temperature at a range of 1100–1150 °C should be suitable enough to a conversion of total nickel to metallic nickel and partly inhibited the conversion of total iron. Ultimately, the obtained ferronickel alloy with a nickel content of 7.32% and an iron content of 84.15% was prepared successfully from the lowgrade nickel laterite ore containing a nickel content of 1.92%. Nickel and iron recoveries were 96.72 and 89.08% respectively, which achieved the highly efficient recovery and utilization of iron and nickel from low-grade laterite nickel ore

By J. Seiter, S. Cox, E. Kim

Mining has always been among the most hazardous of occupations, and with the increasing demand for coal and minerals, safety in mines assumes even greater importance. Worldwide, underground miners are being exposed to noise and respirable dust hazards associated with roof bolt drilling. These hazards are now being understood to cause irreparable damage to the health of miners. The objective of this research was to discover if a polycrystalline diamond compact (PDC) drill bit generates less respirable dust and hazardous noise than a competing tungsten carbide (WC) bit in dry vacuum drilling. In order to control the drill parameters the drilling tests were conducted in a laboratory setting. The results were obtained by determining the quantities of dust and noise generated using each drill bit and analyzing those levels, using monitoring devices and software to collect the data. This paper includes information on the experimental setup, equipment used, drilling parameters, and data collected. Our results indicate that PDC bits produce significantly less noise and dust than WC bits. Our findings can contribute to improving the working conditions of rock bolter operators by reducing noise and dust generation.

Jan 1, 2014

By Stavros H. Constantopoulos

Mediterranean regions such as Greece, Turkey, Cyprus, Corsica and New Caledonia have experienced epidemics of malignant mesothelioma as a result of non-occupational, ??domestic?? exposure to tremolite asbestos and fibrous erionite. This exposure to tremolite asbestos and fibrous erionite is typified ??domestic?? due to its prevalence in regions with natural deposits of tremolite asbestos (or fibrous erionite) where the material from tremolite asbestos or fibrous erionite is used for domestic applications such as whitewashing. However, these exposures may be useful in examining the potential consequences of even small amounts of amphibole asbestos fibers in the ambient air. It can also elucidate the effects of fibers that behave like amphibole asbestos. However, this type of exposure is not useful for studying the potential effects of small amounts of asbestos in the ambient air of big cities due to the differing nature of the fiber types and modes of exposure between the regions. © 2008 Published by Elsevier Inc. Keywords: Tremolite asbestos; Erionite; Domestic; Environmental; Exposure

Jan 1, 2007

By M. C. Azar, W. B. Mason, G. L. Anderson

Eminent domain overview Eminent domain is the power of the Government or a municipality to take property for public use without the consent or acceptance of the owner. Typically, the agency taking the prop¬erty will make an offer, hoping the owner will immediately accept and allow work to begin. If a mutual resolution regard¬ing its value cannot be reached, how¬ever, the municipality will institute a condemnation action in court seeking possion of the property. This is when the problems begin. The power of the Government to take the subject property is limited by Federal and state constitu¬tional requirements to pay "just com¬pensation" for the property. The exact nature of an owner's prop¬erty has been the subject of much debate and discussion. It is generally under¬stood, though, that property is consid¬ered to be "every kind of right or inter¬est, capable of being enjoyed and recog¬nized as such, upon which it is practi¬cable to place a money value" (US vs. 53 114 Acres of Land). A taking, for condemnation purposes, is considered to occur whenever there is a substantial interference with the free use and enjoyment of the property. Rarely is the necessity for the taking ever challenged and more rarely is the taking ever successfully challenged. When a taking occurs, it is not only the fee owner who is entitled to compen¬sation. Every person holding an interest in the subject property will be recog¬nized. Thus, all persons who at the time of taking have a compensable interest in the property will be made parties to the case (Swanson vs. US). Minerals, like all other interests in land, are recognized as property rights, giving the owner the power to dispose of them as he or she sees fit. Thus, the only remaining considera¬tion is only "just compensation." Ex¬actly what "just compensation" is has been difficult to define. Generally, it is that amount of money that will "put the person in as good a position as the per¬son would have been in had the taking not occurred." The owner must not be forced to sacrifice or suffer by receiving less than full and fair value for the prop¬erty. Every element that effects the value of the land and that would influence a purchaser must be evaluated. Courts have employed a variety of techniques to determine just compensa¬tion but have generally relied on market value as the standard for measuring compensation to the owner. The deter¬mination of market value is based on sales, income, costs, and use. These factors have been employed in various ways but can be summed up as: -The highest estimated monetary price the property will bring if exposed for sale in the open market with a reason¬able amount of time allowed to find a purchaser who is buying with knowl¬edge of all the uses and purposes to which it is adapted and for which it is capable of being used. • The amount the property would bring if it were offered for sale by one who desired, but was not obliged, to sell, and was bought by one who was willing, but not obliged to buy. • What the property would bring in the hands of a prudent seller, at liberty to fix the time and conditions of sale. • What the property would sell for in negotiations resulting in sale between an owner willing, but not obliged to sell, and a buyer willing, but not obliged to buy. • What the property would be rea¬sonably worth on the market for a cash price, allowing a reasonable time to affect a sale. (Michigan Standard Jury Instructions). Special consideration regarding mar¬ket value is given when the taking is only partial, rather than complete. An example of this partial taking is when a state highway cuts across the northern half of a parcel of property, leaving the rest behind for the owner. A variety of problems can be immediately seen. In a partial taking, the owner is permitted to recover not only for the property taken, but also for any loss in the value of the remaining property. The measure of compensation for partial taking purposes is generally the difference between the market value of the entire parcel before the taking, and the market value of what is left of the parcel after the taking (Michigan Stan¬dard Jury Instructions). Determining the partial taking value for mineral bear¬ing lands is the difficult issue.

Jan 1, 1989

Tracer gases are an effective method for assessment of mine ventilation systems, but their dispersion characteristics can differ substantially as ventilation parameters, such as flow path and velocity, vary. This research utilizes Computational Fluid Dynamics (CFD) to model a simplified full scale model mine, details a sensitivity study examining mesh size for an underground coal mine simulation, and examines gas dispersion parameters to determine the optimal model methods for simulation of tracer gases in underground coal mines. These models can be used to determine how a given tracer gas profile might be generated in a mine or areas of a mine that are not accessible, for example, immediately following a mine disaster. Accurate simulation scenarios can allow for the remote determination of the status of the ventilation network, but the sensitivity of the simulation at mine scale must be carefully examined.

Jan 1, 2012

By Troy Holm, Matthew L. Fuller, Frederick H. Earnest

Virtual Reality Animation Of The Proposed El Dorado Mine In El Salvador Assists Regulators In Reviewing An EIA

Jan 1, 2005

By Stanley Lefond

The health of the industrial minerals industry appears to be improving year by year. In fact, preliminary information suggests that only three commodities (asbestos, bromine, and sulfur-other) failed to show a production gain in 1984 over 1983. In 1983, 10 commodities failed to post gains and six remained constant. The total value of industrial mineral production in 1984 was $16.7 billion, up $1.4 billion from 1983. Cement, clays, gypsum, and crushed stone production increased. Since these are used in housing and construction, this suggests these industries are moving out of their recent doldrums. Barite and clay production also improved in 1984. Local US barite production, however, still has a long way to go to attain the 1981 high of 2.6 Mt (2.9 million st). Barite imports remain high. But they are not as high as the 1982 importation of 2 Mt (2.3 million st). Bentonite production in 1984 increased 20% in volume and 25% in value over the previous year. This suggests improvement in the drilling industry and an increase in demand for iron ore pelletizing grades. All in all, the industrial mineral industry is alive and well. And it shows signs of great improvement in the next few years. Many thanks to those industrial mineral technical committee members for their assistance in assembling this industrial minerals review: M. F. Dibble, H. W. Allen, G. H. Gallup, S. G. Ampian, D. W. L. Spry, H. G. Fleshman, and L. J. Czel.

Jan 5, 1985

By Michael Hughes, Paul Bonapace, Harry Charalambu, Stephen Rigbey

Ontario Power Generation is building a 10.4-km water diversion tunnel in Niagara Falls, Canada. The tunnel is a two-pass, cast-in-place prestressed concrete-lined pres-sure tunnel with a nominal internal diameter of 12.7 m. It is mostly situated within the Queenston formation which swells in contact with fresh water and has very aggressive groundwater. Tunneling in this material presents challenges in both design and construction. The tunnel design includes for a membrane to eliminate the potential for rock swelling and to protect the concrete liner from the ground conditions. A unique three-stage Geotechnical Baseline Report (GBR) is being used and is expected to provide an equitable method of dealing with any variations in subsurface conditions.

Jan 1, 2007

By Bruce Cavender

Historically, the processing function has been regarded as efficiently managed as long as production costs were kept low, recovery was adequate and sufficient plant capacity was avail-able. In this paradigm, processing is viewed as capable of making only a limited contribution to a company?s competitive advantage. However, the processing function can provide a primary vehicle for building critical competitive capabilities. Processing organizations should be encouraged to become so accomplished they generate new opportunities for other functional groups and thereby influence a company?s overall strategy. This requires a deep shift in processing?s role, in its self-image and in the expectations of it held by managers in other functions. Specific plant improvement techniques ? total productive maintenance (TPM), loss control, etc. ? should be viewed primarily as means for building strategically valuable processing capabilities. Different improvement strategies create different kinds of capabilities and present new strategic options. Broadly speaking, a mineral-producing company seeks competitive advantage through two principal activities: the development of new mineral production and reserves and the optimization of existing operations. These lead to increases in ore reserves, production levels and cash flows that are manifested in increased profitability and, hopefully, increases in the price of the firm?s stock. The profitability of a minerals company is a function of the overall profitability of the industry sector in which the company participates and the firm?s competitive position within that sector relative to those of its competitors. Competitive advantage within the industry comes from two sources: the ability to maintain lower prices than competitors for the same product (cost leadership), or from the sale of products with unique properties that justify higher prices (product differentiation; Porter, 1980). Most mineral companies produce fungible commodities that are sold to anonymous customers, and sustainable cost advantage is the only long-run strategy available to these companies to enhance profitability.

Jan 1, 2008

The most complete mining show ever held in the United States and the largest exposition of its kind to be held anywhere in the world in 1988. That's how the American Mining Congress is billing its "MINExpo International '88," to be held April 24-28 at Chicago's McCormick Place, the largest exposition facility in the country. MINExpo International '88 will combine for the first time two previously separate AMC-sponsored shows - the International Coal Show and the International Mining Show. Starting with the 1988 show, MINExpo International will be held every four years. The next show, in 1992, will be held in Las Vegas. The MINExpo in Chicago will feature more than 500 mining equipment and services exhibits covering 3 hm2 (320,000 sq ft) of exhibit space. Exhibitors will display products ranging from small safety devices to large earth-moving equipment. MINExpo is one of the few trade shows selected by the US Department of Commerce for its Foreign Buyer Program. Commerce is working with US embassies around the world to publicize MINExpo and to form delegations of visitors from many countries. Overseas visitors to the show will be assisted at an on-site International Business Center. It will provide currency exchange, translation, and other services to foreign buyers. Registrants at MINExpo will also be able to attend their choice of 27 morning-only program sessions. At these sessions, international mining experts from industry, government, and academe will analyze technical, strategic, and policy matters and discuss the outlook for the industry. "Toward the 21st Century" is the theme of this year's program. The technical workshops and managerial seminars are designed to assist mining executives, engineers, and geologists as well as mine superintendents, managers, and foremen in handling their responsibilities. Based on previous attendance at AMC international mining shows, the association says that more than 25,000 persons are expected to attend the Chicago show. It is expected that approximately 15% of the attendees will be from foreign countries. The Soviet Union will be among those exhibiting at MINExpo. The Russians have leased more than 2.8 dame (3000 sq ft) of space to display their mining machinery and equipment. It is the first time that the Russians have joined in an exhibition of mining equipment in the US. The two largest manufacturers of mining equipment in the Soviet Union, Setmash and Avtoexport, will put on display in Chicago a variety of Russian-made equipment. It will range from 100 t (110 st) heavy-duty dump trucks and diesel engines to drilling, hoisting, and conveying equipment. In addition to some 400 US exhibitors of mining equipment and services at MINExpo, nearly 100 companies will be present from other major mining nations such as Australia, Canada, Great Britain, Japan, the Netherlands, and West Germany. And, for the first time, a Chinese manufacturer will take part in the AMC show, participating with its US marketing partner.

Jan 3, 1988

By V. Svalbonas

The process of grinding mill quality assurance brings with it associated truths and myths. When the mill quality assurance process took its first great steps forward in the late 1970s and early 1980s, they were in response to the conditions existing, in our industry, at those times. In the late 1990s, we are faced with different conditions, and problems, and need fresh solutions. Yet the system developed for the early 1980s has produced no new approaches for the late 1990s, becoming instead more hardened and entrenched. This lack of development and actual resistance to research is now costing the industry significant amounts of money in late start-ups and useless scrap loss.

Jan 1, 1999

By G. Kim

The influence of bacterial growth phase on the flotation behavior of malachite has been investigated in a well-controlled Hallimond tube system. The microflotation tests were conducted for malachite (45?53 µm) using different amounts (bulk phase concentration=1×108?5×109 cells/mL) of Rhodococcus opacus (R. opacus) as a collector, which was grown at mid-exponential versus stationary phase, at a constant speed (340 rpm), pH (6), and malachite-bacteria interaction and flotation time (each 10 min). Hug differences between R. opacus cells in mid-exponential and stationary phase was observed from the results for electrophoretic mobility and flotation tests. Specifically, the isoelectric point of the cells in the stationary phase was lower than that in the mid-exponential phase, suggesting that the amount and distribution of surface functional groups onto cell surfaces are likely different. Additionally, the cells in stationary phase led to significant increase in the flotability compared to those in mid-exponential phase over the background bacterial concentration level of 1×108?5×109 cells/mL. Furthermore, the flotation efficiency tended to increase with increasing cell dosage for stationary phase cells while no distinct difference was observed for mid-exponential cells.

Feb 27, 2013

By Ray Brainard

Charleston Water System?s Daniel Island Extension Tunnel, initially thought to be the simplest of the four replacement tunnels to design and build, became the most challenging after the discovery of an unexpected 30-ft thick lens of sand in the normally consistent Cooper Marl while sinking a shaft on Daniel Island. This paper will explore the challenges involved with determining the extent of the unforeseen lens of sand, the accelerated boring program, and the redesign of the vertical alignment?keeping the alignment between the sand layer and the bottom of the Cooper River. It will describe how the challenges were overcome, and how the Owner, Engineer, and Contractor were able to team together to achieve the desired results.

By S. K. Sharma, ANKUSH GALAV, G. S. P. Singh

Providing a suitable protective water barrier pillar (PWBP) is common to reduce inundation hazards in underground coal mines. The imperative factors influencing its performance include the water head acting on the pillar, cover depth, pillar width, strength properties, and permeability characteristics. The mechanical failure of such pillar is a stress-controlled phenomenon, whereas the hydraulic failure is a strain-based phenomenon. A finite-difference numerical modeling approach was developed to study the hydro-mechanical coupled behavior of protective water barrier pillars. The mechanical stability was evaluated in terms of the percentage of failed (ZoF) and intact zones. The influence of the strain-controlled weakening on the permeability of the flow medium was studied through the coupling of the mechanical and hydraulic effects. The coupled steady-state model was used to estimate the outflow rate and its hydraulic stability. The adequacy of the protective pillar was also investigated by assessing mechanical stability and capability to resist hydraulic pressure against the maximum expected water head. A seepage rate-based classification system has also been proposed to evaluate the seepage potential and assess the hydraulic stability. The model has been validated for two case studies at the cover depth of 136–189.5 m and the existing pillar width of 16–42 m against the water head of 25–141 m.

Aug 18, 2022

By J. D. McAteer

It is widely agreed throughout the mining community that federal mine safety and health legislation administered by the Mine Safety and Health Administration (MSHA) deserves significant credit for the past quarter-century's remarkable improvements in miner safety and health. Recently, however, it has been suggested that the mining industry in the United States has now evolved to a point that current mine safety and health law may be obsolete. This proposition deserves attention. Today, I propose to give it the close logical scrutiny that is its due. I conclude that the obsolescence of current mine safety and health law is not supported by the evidence. The existing mine safety and health law continues to serve as a critically important supplement to mine operators' safety programs at a modest cost to the taxpayer. At the same time, trends in a changing industry do call for responsive adaptations in the Federal mine safety and health program. I will argue that timely and appropriate responses to changing needs can be accomplished within the framework of existing legislation, provided federal officials avail themselves of the flexibility provided by existing law.

Jan 1, 1996

By Thomas C. Shapiro

This is the second in a series of articles on microcomputers and applications in the minerals industry. The first article (ME, Feb., page 129) discussed microcomputer terms and concepts. This article will discuss software for geology and mining. The third article will cover plant, administrative, and geotechnical software applications. Introduction Geology and exploration are areas where computers have a natural fit. Large volumes of data need to be tabulated, evaluated, and made into maps and reports that allow geologists and management to make a decision on a project or mine. Until recently, the programs that performed these tasks were cumbersome and not user friendly by any stretch of the imagination. Learning time to become an expert in these programs typically would be six months or more. The computers needed to run these programs are expensive mainframes. Several years ago, the use of minicomputers became popular because of their lower cost. Programs were adapted to fit these smaller machines and became friendlier. With the advent of micros, many programs. were rewritten and used the screen capability more effectively, thus providing a real advance in user interface. Programs and Price The definition of micro, mini, and mainframe is becoming blurred. For the purposes of this article, micro refers to either an eight- or 16-bit computer, costing less than $10,000 and, more typically, under $5,000. Mini refers to a 16- or 32-bit computer that typically costs more than $25,000. Mainframe refers to a 32-bit or larger computer that costs more than $250,000. There is a large gray area between micros and minis, and minis and mainframes. Technology and prices are changing so fast that the traditional definitions have become almost meaningless and price has become a better guide. With the arrival of the minicomputer, costs for hardware began to fall, but the programs have tended to remain unfriendly. In some cases, the minicomputer acted as a front end to the mainframe. Cost of both the programs and minicomputers could easily run a minimum of $70,000. A total cost of $200,000 would not have been out of line. The average geologist and company would have a great deal of difficulty justifying such a purchase. The advent of the microcomputer has changed all that. For $3,500 to $5,000, one can buy a 16-bit micro and a printer. Plotters with six pens are available for $2,000 that will produce a 280- x 430-mm (11- x17-in.) map. For several hundred dollars, software is available to act as a word processor, an economic spread sheet, or to perform ground water calculations. In fact, some programs are available for free. Some of these programs are relatively easy to learn. In addition, programs are being developed daily that are easy to use. More importantly, large programs that once ran only on mainframes are being converted

Jan 3, 1984

By Irwan S. Halim

For tunnels in horizontally bedded rock, geologic factors affect the selection and design of the initial supports, including the rock propensity toward parting along bedding and the resulting high potential for rock slabbing during excavation. To evaluate this ground behavior, numerical analyses and results with Mohr-Coulomb, Hoek-Brown, and Ubiquitous Joint constitutive models were used, using the Upper Rouge CSO tunnel in Detroit, Michigan as an example. The different rock models and other geologic considerations are shown to impact the selection of the tunnel initial support and design. This paper emphasizes the appropriate selection of an analytical model based on the site specific geology to achieve an optimum initial support design.

Jan 1, 2008