Search Documents

By David Whitehead

My qualification to speak on the globalization of the the mining industry comes from having worked in the industry in Europe, North and South America, Africa and Australasia in positions ranging from exploration geologist to chief executive. For about a third of my career I have lived and worked in the Southern Hemisphere. And for much of the rest of my career I have been involved in or responsible for activities in the Southern Hemisphere. This has given me the opportunity to experience globalization from the sharp end, as it were. This means speaking English with an Australian accent, Spanish with a Chilean accent, French with a West African accent and Dutch with an English accent. My topic is globalization, especially of the mining industry from a Southern Hemisphere perspective and specifically the experience and history of Gencor in that context. First, I will say a little about what globalization means to the southern part of the world: How and why the South differs from the North and how the challenge of globalization affects a south-based company differently than a northern one. I will also detail how Gencor has made significant progress in globalizing through the acquisition of mining assets from Shell. As Fig. 1 shows, I have divided up the world into northern and southern components, rather than hemispheres. The southern world comprises mainly countries that have emerged from the status of economic - if not political - colonies of nations such as England, Spain, Portugal, France, the Netherlands and, surprisingly, Italy and Germany. I have not considered the Indochinese and Arabian peninsulas in my southern world. The emergence of the. former is still in its early stages while the latter is clearly a part of the northern economic system. Large parts of Africa and South America are geometrically in the Northern Hemisphere but economically in the southern world. The reverse is the case for the IndoPersian peninsula. With the distinguished exception of Australia and South Africa, most of these countries nationalized their mining industries and mineral patrimony after attaining political independence. A major element of the globalization of the mining industry is related to the privatization of the mining industry in these countries and to the opening up of their min¬eral patrimony to non-national exploitation. The Southern Hemisphere is the watery part of the world. It is almost three quarters ocean as against a slight preponderance of land in the north. Economically, ocean areas have only a fraction of the productivity of land, except in a few oil-rich areas like the Gulf of Mexico and the North Sea. The consequence is that even on an economically level playing field we would expect the south to generate only about one third of the world's economic product.

Jan 1, 1997

By R. F. Korcak

There exists a wide array of industrial by-products that can be shown to produce beneficial responses in the soil/plant environment. These materials range from clean coal technology residues produced in the generation of electric power, particularly those high in gypsum, to mineral 'fines' produced by the aggregates and crushed stone industries. A number of these materials will be examined in relation to potential nutritional interactions in soils and crops with emphasis on trace elements. The significance of utilizing these materials in agriculture as a component of sustainable agricultural systems will be discussed.

Jan 1, 1995

By L. V. Wade

The use of longwall/shortwall mining systems is under increasing scrutiny by the U. S, coal industry as a means to reverse the decline in productivity. The success of these mining systems depends to a great extent upon designing the system hardware to best suit local conditions. Of particular importance in this regard is designing the various elements of the total ground support system, including face, face end, and gate road supports, to accommodate local geologic conditions. This presentation centers on the problem of selecting the face support system. The existing geologic situation can influence the selection of the face support hardware in a variety' of ways. In general terms, these influences can be grouped into the following four areas: 1. The capacities required of the support unit; 2. The roof, coverage supplied by the support units; 3. The flexibility required of the support unit to meet changing geologic conditions; and 4. The required stiffness characteristics of the individual support units both vertically and horizontally. The following will center on the first area, i.e., the required d capacities of the support unit, in particular, the maximum required load density for a particular geologic situation.

Jan 1, 1976

By M. Noaparast, F. Woodcock, A. R. Laplante

A novel methodology for estimating gold recoveries in gravity-separation circuits is presented. The methodology makes use of a population-balance model. The model represents gold liberation, breakage and classification behavior and applies preconcentration and recovery performance curves to gravity-recoverable gold. The derivation of the necessary parameters is explained and demonstrated using data from an actual gravity circuit and from a projected application. The methodology makes it possible to estimate the performance of a gravity circuit having a large gold circulating load and a relatively-low unit recovery (e.g., a jig) or having a high recovery on a bleed of the circulating load (e.g., a Knelson Concentrator).

Jan 1, 1996

By Vladimir Jindrich

This paper presents a history of a successful three year effort in locating a large, economic deposit of high purity limestone. The exploration program has been carried out by Ernest K. Lehmann & Associates, Inc., geological consultants, for Dravo Corporation, owner of the limestone property which is now under development. The permission of Mr. L. P. Struble, Jr, President of Dravo Lime Company, and Mr. M. W. Robinson, Director of Research and Development, to present this paper is gratefully acknowledged. The limestone property is on the Ohio River near Maysville in northern Kentucky, 60 miles east of Cincinnati (Fig. 1). The area lies at the eastern flank of the Cincinnati Arch, a regional structure where the Lower Paleozoic strata crop out below the adjacent younger sedimentary rocks of the Illinois and Apallachian basins. In general, the limestone formations of the Middle Ordovician High Bridge group offer the best potential for industrial limestone in Kentucky and adjacent parts of Ohio and Indiana. These formations are exposed along the axis of the Cincinnati Arch in central Kentucky. Toward the west, east and north, strata of the High Bridge group are progressively deeper, concealed beneath a succession of interbedded fossiliferous limestone and shale. The High Bridge group limestone formations are shallow-marine deposits largely of tidal flat, shallow lagoon and related environments. Principal lithologies include cryptocrystalline micritic limestone and crystalline dolomitic limestone to dolomite. Shale and bioclastic limestone are subordinate but the proportion of shale increases in the basal formations. Characteristic, is the occurrence of several thin beds of bentonite that serve as regional stratigraphic key horizons.

Jan 1, 1975

By Daniel Maine

Swelling clay soils have been problematic to many types of infrastructure in the United States. However, their impact on underground construction is often misunderstood. The use of swell pressures in design of initial tunnel and shaft support lacks proper guidance and is often mis-interpreted. This paper provides insight and guidance on how to implement a geotechnical investigation program to determine if swelling soil exists at a site and how it impacts the design of temporary support systems for underground projects. An example is provided for how swell pressures were incorporated into the design of an initial support system for a rib and lagging tunnel system and problems that occurred.

Jun 23, 2024

By Norman Weiss

The purpose of this paper is to relate progress in the engineering field called Minerals Beneficiation to undergraduate and graduate education in our colleges and universities. So mach has been written recently about the education of scientists and engineers that I've had to struggle against the temptation to repeat what has been often said before, particularly because man like Robert Mehl of Carnegie Tech, Antoine Gaudin of MIT, H. M. Davis of Penn State, and John Vanderwilt of Colorado School of Mines have recently written many quotable paragraphs on the subject. In the matter of progress, the rapidity of proliferation in the area of physical and chemical beneficiation is convincing proof that this is indeed a lively art, and having been a millman for 35 uninterrupted years I prefer to lean on personal observations to some extent, rather than on statistics and charts v culled from the journals. I propose in this paper to talk first about the progress we've made in our branch of the mining industry in the last 3 decades--particularly in the last few years--and try to show that future progress will depend upon the quality of education and capacity for research possessed by our colleges. The second part will deal with some of the problems the colleges encounter in trying to fulfill these responsibilities.

Jan 1, 1959

By William Lodding

That grinding may change a crystalline material both in a physical and in a chemical sense has been shown by a number of authors in recent years. Thus Mackenzie (1) and Bartha (2) reported the effects of careful grinding on muscovite, quartz, gypsum, dolomite, etc. Increase in specific surface produced by grinding implies increase in total energy of a system. Newly produced surfaces are chemically more reactive; dislocations may be introduced during grinding, and existing strain may be released by the same process, as shown by Holt et el. (3) All these changes are easily detected by thermal analysis, but it is not easy to separate the multiplicity of effects registered and to arrive at quantitative interpretations. This paper is an attempt to analyze by the use of thermal analysis some effects produced in grinding. In differential thermal analysis (DTA) one measures all thermal changes occurring in a substance during heating or cooling. Chemical changes, such as decompositions, synthesis, oxidation, reduction, etc., and physical changes such as phase transformations, changes in specific surface and in thermal conductivity, strain release, etc. By thermo gradmetric analysis (TGA) on the other hand only chemical changes involving weight loss or gain are recorded. Similarly gas evolution analysis (GEA) will register only reactions involving gas evolution, including water vapor, and oxidation-reduction. By performing two or all three of these thermal methods of thermal analysis simultaneously and on the same specimen one can separate the different effects registered and by difference evaluate their magnitude.

Jan 1, 1966

By Roger Escoda Estelrich, Joan Carles Casado Ortega, Mitchell Gerdau, Jose Raul Martinez, Jeb Pittsinger, Frank Perrone

The existing Chesapeake Bay Bridge-Tunnel complex is being expanded to include the Parallel Thimble Shoal Tunnel. This will be a subaqueous bored crossing between two islands constructed for the original 1960s immersed-tube tunnel. Jet grouting was employed by the Chesapeake Tunnel Joint Venture (CTJV) to provide watertight base plugs, launch and retrieval blocks for the tunnel boring machine (TBM), a TBM canopy to limit ground movement, and a retaining wall to enable off-island excavation: all within hydraulically placed sands. This paper will review the design and construction challenges, including soil permeability and recharge, grout communication, installed grout strengths, and remediation requirements.

Jun 23, 2024

By Henry F. McCabe

The principals of McCabe Industrial Minerals, Inc., have been involved in the mining, processing, and marketing of nonmetallic minerals for more than 40 years. In addition to marketing nonmetallic minerals produced by other companies, McCabe Minerals owns and operates three plants that produce headlap-roofing granules, with 25 employees and annual sales approaching $6 million. During its 22 years of operation, the company has developed many different markets, and a list of factors that is used in making our marketing and feasibility studies. These criteria (Table 1) are used extensively by the company in all of its projects, and we present this and other data about the company in this brief report. HISTORY OF THE COMPANY A brief outline of the history of McCabe Industrial Minerals follows: I. McCabe Industrial Minerals, Inc. (Formerly McCabe-Woody & Co.). A. Founders: 1. Henry F. McCabe (experience): a. Heart of Texas Sand Co., Brady, Texas (1959-67) b. Delta Mining, Mill Creek, Oklahoma (1967-76) 2. A. H. Woody (experience): a. Heart of Texas Sand Co., Brady, Texas (1961-65) b. Featherlite Corp.-Light-weight aggregate

Jan 1, 1999

By Jennifer B. Leinart

With the signing of the North American Free Trade Agreement (NAFTA), Canada, the United States and Mexico entered into an international experiment in economics amid a cloud of controversy that still lingers. Central to the controversy are the disparities in wages that exist among workers in the signing countries. Wage surveys completed by Western Mine Engineering show the degree of disparity that exists among the mining industries of those three countries. Labor costs constitute 30% to 50% of operating costs. So these wage differences are a matter of interest to the mining industry. It is unclear how much of a factor they are in determining where companies search for and develop new mines. That depends on where minable deposits are expected to be found. However, a deposit that may not be minable in the United States or Canada may be minable in Mexico because of lower labor costs. Some adjustments are anticipated for the Mexican mining industry if and when its wages begin to approach comparability with US and Canadian wages. Table 1 combines the results of four recent surveys. It lists benchmark wages for mining job titles common to all the countries. About 220 mines are covered by the combined surveys. Canadian miners' wages, converted to US dollars, are typically 75% to 95% of US wages, while Mexican miners' wages are less than 10% of those in the United States. Table 1 also shows that wage disparities are not confined to international borders. In fact, the difference in average wages between the US coal industry and the US metal and industrial mineral industries is greater than between the Canadian and the US mining industries overall. Table 2 shows that managerial, technical and administrative salaries show similar, but less pronounced differences among the three countries. Salaried personnel at Canadian mines earn 80% to 90% as much as their US counterparts, while those in Mexico earn 20% to 30% as much. Here again, average US coal salaries exceed average salaries for the US metal and industrial mineral industries.

Jan 1, 1998

By Y. A. Attia

A study was performed on selective flocculation and dispersion for ultrafine coal cleaning. A totally hydrophobic polymer, FR-7A, was employed as the selective flocculent for coal, sodium metaphosphate (SMP) as the general dispersant for shale and a synthetic polymeric product, polyacrylic acid-xanthate (PAAX), as the selective dispersant for pyrite. In the adsorption tests, nephelometry and spectrophotometry were employed for determining the concentration of FR-7A and PAAX in the solutions respectively. The adsorption tests indicated that: a) FR-7A has a higher affinity toward coal and pyrite than that for shale; and b) PAAX has a much higher affinity toward pyrite than toward coal and shale. In the selective flocculation tests, the ash-forming minerals can be efficiently rejected using sedimentation as the separation method. However, due to their relatively high specific gravity, pyrite particles co-settle with the coal flocs. To reject fine pyrite, a froth flotation was used for floc separation. The one-step flocculation-flotation process could reject more than 70% of each of the pyritic sulfur and ash minerals, while recovering more than 85% of the coal.

Jan 1, 1990

By P. L. Yorio, D. R. Willmer

"The current paper presents the results of a study designed to explore the types of practices that are fundamentally important to developing and maintaining comprehensive risk-based health and safety management systems (HSMS) in mining organizations. Eighteen practicing health and safety (H&S) executives, managers, and professionals from a variety of mining commodities were asked to assess the fundamental importance of 20 distinct elements and 133 different practices assembled from a review of several HSMS consensus standards. The research approach assumes that developing and maintaining a robust HSMS requires unwavering attention to activities designed to either: 1) directly contribute to a risk management system’s plan-do-check-act cycle; or 2) build an organization’s internal infrastructure without which the cycle cannot be sustained. The results of this study suggest that the following areas require consistent focus and attention: Leadership Development; Accountability; Knowledge, Skills, and Abilities Development; System Coordination; Culture Enhancement; Behavior Optimization; and Risk Management Studies. Each element and its corresponding top-ranked and top-rated practices are discussed.INTRODUCTION Since the time of the Industrial Revolution, occupational health and safety (H&S) management has been a topic of practitioner thought and academic inquiry (1). In the U.S., decades of regulation and research have resulted in a surplus of prescriptive information (techniques, tools, approaches, standards, programs, practices, policies, etc.). With an abundance of such information, a simple H&S solution to address a problem in the U.S. mining industry may seem straightforward. Counter to this assertion, however, some evidence suggests that the abundance of information may create complexity and cause confusion in the minds of organizational leaders and H&S managers, ultimately discouraging the voluntary pursuit of a sound approach (2). In line with this perspective, in 2006 the U.S. National Mining Association (NMA) formed an independent commission to examine H&S management issues within the mining industry. The findings of the commission called for the mining industry to adopt a risk-based management paradigm. In the presentation of its findings, the commission stated that “…every mine should employ a sound risk-analysis process, should conduct a risk analysis, and should develop a management plan to address significant hazards identified by the analysis” (3). Grounded in the well-known plan-do-check-act cycle, the recommended risk management system allows for mines to ground strategic management choices in their mine-specific hazards and risk profiles"

Jan 1, 2015

By R. Jacobson

This paper presents comparison of proposed future solution and in-situ mining methods for in-situ leaching and recovery of uranium, gold, silver, and copper. We propose to show that in the future new extraction methods for each metal will eventually evolve for each hydrometallurgical process step, i.e. in-situ leaching, recovery, and concentration; precipitation and reduction; and drying, when required--without generating waste or bleed streams. In the future, to be highly profitable, these forms of mining will develop into an integrated system to eliminate waste streams using safe, powerful lixiviants. This integration will include, with some exceptions, improvements in the following areas of process development: 1. Lixiviant selection and in-situ leaching technique, 2. Target metal recovery and concentration (at a surface hydrometallurgical facility) from the circulating pregnant lixiviant stream, 3. Target metal precipitation or reduction, where decant water from the precipitate dewatering step is reusable for resin or solvent strip liquor (eluant), 4. Final preparation of target metal for sales, i.e. drying, purification, casting, packaging, 5. Restoration where most of the groundwater restoration process is performed at the same rate as multi-wellfield mining.

Jan 1, 1987

By David D. Spencer

As in many other areas of the Mexican economy, the legal rules applicable to mining in Mexico have been changing fast. Mexico's mining sector is opening up to levels of international participation that were unforeseeable just a few years ago. Over the last several years, Mexico has made dramatic changes in its trade and investment policies. Many of these changes have their roots in the administrations of Miguel de la Madrid and perhaps even Jose Lopez Portillo. However, the current administration of President Carlos Salinas must be given credit for articulating, advancing, promulgating and implementing these changes. Just a few short years ago, few people believed Mexico would repeal so many of its restrictions on foreign investment and lower its average tariff level from something around 100% to less than 10%, where it is today. NAFTA and mining The North American Free Trade Agreement (NAFTA) is the most comprehensive international expression of Mexico's new policies. Except perhaps for the agreements establishing the European Union, NAFTA is the most detailed trade agreement ever written, consisting of about 2000 pages. The provisions of NAFTA with the greatest relevance to the mining industry include the chapters on investment and government procurement. Many mining companies may also find the temporary work provisions relevant. Finally, no discussion of NAFTA and the mining industry would be complete without some mention of the North American Agreement on Environmental Cooperation, the so-called Environmental Side Agreement.

Jan 1, 1994

By Diler Katircioglu-Bayel, Oner Yusuf Toraman, Safak Gokhan Ozkan

One of the most energy-intensive processes for producing submicron range calcite is stirred media mill. In the present work, numerous operating parameters such as solid mass fraction, grinding media size, media filling ratio, and grinding time have been investigated using a vertical type stirred media mill. The results are evaluated on the basis of mean particle size, specific surface area, and specific energy consumption. After conducting this study, optimum experimental conditions found to be as 70% media filling ratio, 25% solid mass fraction, 1 mm grinding media size, and 120 min grinding time. Besides, energy savings up to 22% were achieved with the choice of proper media size.

By J. S. Murty

In this paper, a report is given of studies undertaken in a laboratory rod mill to obtain the optimum conditions for the desired particle size distribution for long-distance transportation of coal through slurry pipelines.

Jan 1, 1987

By C. Ernst

The underground operation at Barrick?s Cortez Mine, located near Elko, NV, required the construction of a 12 foot diameter smooth-lined ventilation shaft. Barrick preferred to mechanically excavate from the ground surface without putting people in the excavation and considered blind drilling by Frontier-Kemper Constructors the best option. Design and construction challenges arose throughout both the excavation and lining stages. A large portion of the rock to be drilled was highly fractured. Important risks that were addressed included water loss into the formation, zones of squeezing ground, damage to drilling tools caused by blocky ground and fallout, and potential hazards during cast-in-place concrete lining. Detailed explanations of these challenges and the methods used to overcome them will be described.

Feb 23, 2014

By Kenton E. McElhattan

Financial analysts have often called National Mine Service Co. the only "pure play" company to the mining industry, meaning that an investment in NMS is an investment in the mining industry. As a leading manufacturer and supplier to the industry, National Mine Service does enjoy a close and direct relationship with mining. It is the only independent company that offers products and services that include mining machinery, health, safety, instrumentation, mine supplies, and reconditioning services for hydraulics, electronics, and machinery. But what is a positive relationship in periods of economic upturn can be eauallv as negative during the downturns. In fact, National Mine Service has felt the resounding blows of the current recession in the mining industry. Two-Fold Strategy Rising unemployment, corporate losses, bankruptcies, and mine closings in particular have directly affected NMS. But the company embarked on a strategy several years ago that included a two-fold approach to becoming less dependent upon the vagaries of the US coal industry. One strategy was to develop additional products and services for other mineral industries such as potash, trona, and salt and, where possible, apply the technology developed for the mining industry to industrial markets. The other strategy was to become a more international company. The objective was to make export sales a minimum of 10% of total corporate sales. Even today, NMS believes this is a good strategy as opposed to diversifying because its expertise is in mining, not in other areas. A review of NMS's fiscal 1982 annual report indicates that the company's strategy did begin to pay off. 1982 was a turnaround

Jan 2, 1983

By William A. Prosser, Kyle R. Ott, Philip Rice

"INTRODUCTION The existing Baltimore and Potomac (B&P) Tunnel accommodates Amtrak (National Railroad Passenger Corporation) and MARC (Maryland Rail Corporation) service between Baltimore, MD and Washington, DC and occasional local freight service. The Baltimore and Potomac Tunnel Replacement Project proposes new tunnel construction through Baltimore, Maryland along the Northeast Corridor (NEC) that maintains connections to Baltimore Pennsylvania Station. After the Replacement Project is constructed and operational, the disposition of the existing tunnel must be determined. The tunnel could be abandoned; however, considering its location in a congested downtown, alternative uses have been considered to take advantage of this unique piece of infrastructure by repurposing it. Alternative uses for the existing 140-year-old B&P Tunnel may end up being cost effective and should be considered, as the tunnel can be made accessible to construction crews for extended periods of time that will allow for efficient work activities unlike when it is fully operational. Possible alternatives include conversion for non-rail use, rehabilitation, or complete modernization for continued rail traffic. The following paper describes the four potential fates of the conceptual designs for the existing B&P Tunnel. The four concepts include: • No Build – rehabilitate to keep the tunnel operational. • Abandonment – complete or partial sealing of the tunnel. • Adaptive Re-Use –repurpose the tunnel with sustainable building practice. • Full Rehabilitation and Modernization – bring to current fire-life safety aspects. Of the four concepts, only the no build addresses maintaining the tunnel while it is under traffic. The remaining fates address the existing tunnel after the new tunnel is operational and railroad traffic has been diverted to it. Development of these conceptual designs were provided in a concept design study (Parsons Brinckerhoff/Parsons, 2015) that supports the National Environmental Policy Act (NEPA) review process for the Project, which includes evaluation of possible alternative uses of the existing B&P Tunnel."

Jan 1, 2016