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By Steve Kral

A near-record crowd of mining history enthusiasts made the trip to Leadville, CO in September to attend the National Mining Hall of Fame and Museum’s 19th induction banquet. Dressed in Victorian garb, black tie tuxedos and formal gowns, the 268 people honored four distinguished men who made a lasting impact on the U.S. mining industry. They joined 188 other inductees. The first induction banquet took place in 1988, with about 500 people attending.

Jan 1, 2007

The National Institute for Occupational Safety and Health (NIOSH) conducted a monitoring field study to optimize the rib control plan in a room-and-pillar coal mine. The study mine is located in the Central Appalachia coal basin. Two monitoring sites were selected at different sections in the study mine. The selected sites have different overburden depths and geologies. The instrumentation plans at study sites include borehole pressure cells installed at various depths in studied pillars, rib and roof extensometers and load cells mounted on number of the rib bolts. The instrumentation results and observed geology for one of the study sites showed great potential for optimizing the rib bolt plan at that section of the mine. Therefore, a rib support optimization study was followed using numerical modeling technique. A calibrated threedimensional model was developed using the instrumentation results of the optimization section. The calibrated model was used to determine the optimum rib support for expected overburden depths and rib heights. Baseline rib bolt patterns were assumed for the optimization study. Additional rib bolts, above and beyond the baseline bolting parameters, were outlined and identified as solutions to contain the rib fracturing identified by the modeling results.

Jul 28, 2020

By Patrick J. Doig

The Crosstown 7 Collector System, Contract C28G11, is part of the Milwaukee Metropolitan Sewerage District's Waste Pollution Abatement Program. The contract involves the construction of 1.6 km (1 mile) of 3 m (10 ft.) diameter tunnel in soft ground. The tunnel is 10 m (35 Ft.) below surface and passes through a variety of soils. The eastern leg of the tunnel along Bruce Street is mainly in till material, a stiff, relatively dry clay. The northern leg along 16th Street starts in till, and continues in estuarine deposits - moist sticky clay, with intrusions of alluvial sand and gravel. The contract specifications required that the tunnel be constructed either under compressed air or with an earth pressure balance tunnel boring machine. The S. A. Healy Co., the general contractor, chose the latter option. Additionally, a single pass, pre-cast concrete segmental liner was selected as the lining system. The mining machine was manufactured by Lovat Tunnel of Canada and the segments were made by the Sehulster Company of Milwaukee. The use of this combination of machine and lining is relatively new to the United States and this tunnel is the most extensive built to date with a gasketed, segmental single pass lining for transportation of fluids. This paper details the various aspects of the construction of the tunnel and associated shafts.

Jan 1, 1989

By S. Makni, R. E. McIvor

Grate discharges historically outnumbered the overflow type of industrial wet ball mills. However, overflow discharge mills now strongly dominate. In order to understand their comparative advantages and disadvantages, Corem carried out a broad review of this topic. Where the data made it possible, the Functional Performance Equation was used to separate circuit classification from mill grinding effects. Batch tests were conducted in a torque-metered mill at different slurry levels. This paper presents the outcome of these investigations, which is a very strong case for the industry to once again consider grate discharges.

Feb 1, 2023

By H. H. Murray

The largest reserves of palygorskite in the world are located in Anhui and Jiangsu Provinces in East Central China. The deposits are Middle Miocene in age and range from 3 to 6 m in thickness. The deposits are the alteration product of basaltic volcanic ash. The Chinese Geological Survey estimates the palygorskite reserves are in excess of 200 million tons. The elongate particle shape results in unique colloidal properties. Large quantities are exported to Japan, Taiwan, Southeast Asia, New Zealand, Australia, and West and Gulf Coasts of the United States. The markets include agricultural carriers, paint, joint tape compounds, animal feed binders, catalyst support, drilling muds, and suspending agents for chemicals, pharmaceuticals, and medicines. The viscosity is high and the quartz content is generally 5% or less.

Jan 1, 2009

By C. E. Stack

For the purposes of this presentation, "refractory clay" is intended to include any clay suitable for refractory products and thus represents a description based on industrial application. Other common examples based on use would be white-ware clay, bleaching clay, paper clay, or cement clay. Most users and producers of refractories have specific quality requirements which determine the quality or type of clay that can be utilized. Many clays can however be interchanged or substituted in use by changing manufacturing processes or upgrading less desirable clays. U.S. Bureau of Mines publications (Ampian, 1985) categorize days into six groups. These are kaolin, fire clay, ball clay, bentonite, fuller's earth, and common clay. These are practical groupings based on clay production and usage in the United States. Among these groups bentonite, fuller's earth, and common clay are primarily composed of the minerals, smectite, illite, or chlorite, and are non-refractory. Kaolin, ball clay, and fire clay are commonly used in refractories and thus qualify as refractory clays.

Jan 1, 1986

By Mark E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problems simultaneously. Previous attempts at solving these problems separately, although successful, fail to take into account the interrelationships between these problems. Project structure serves as the outline of this paper, which is directed towards a mining engineering audience. Generalized in its organization, this concept is useful for long, intermediate and short range scheduling. Actual applications are mentioned which show that the concept is also applicable to mining a variety of ores.

Jan 1, 1982

By Y. J. Wang

Along with the inexpensive availability of computing hardware, a proliferation of powerful personal computers is being realized throughout the mining industry. People from every arena within the industry are designing, developing, and/or applying mining specific software, which is increasing at a rapid rate. In this section applications (or potential applications) that are being made in the analysis and design of mine systems are discussed, including the design of compressed air networks, the simulation of hoisting operations, analysis of longwall face maintenance, and a summary of computer and software applications for analysis and design of coal operations. In "Computer Aided Design of Mine Compressed Air Networks" the authors describe software, called CompAir, and the underlying theoretical and mathematical foundations of it that can be used to make accurate, cost-effective designs of compressed air systems for mines. It includes algorithms for network analysis and the optimization of pipe diameters. The techniques embodied in the software replace traditional rule-of-thumb approximations which have been used in the past and avoid the operating problems that often result from using average, steady-state parameter values, estimated for ideal operating conditions. CompAir, coded in Turbo Pascal for personal computer use, bases calculations on compressible fluid theory, which gives more accurate results than incompressible fluid theory whenever high flow rates or long line distances are involved. The net- work and pipe diameter analysis is formulated as a nonlinear programming problem. The solution technique requires a trial and error approach that iteratively applies the unconstrained optimal pipe diameter algorithm to successive solutions of the constrained network problem until the diameters become "fixed." The authors conclude by recommending the use of a mine-wide monitoring system to improve cost control and provide a better understanding of flow regimes in compressed air networks.

Jan 1, 1989

By Edward R. Mueller

As an alternative to a million dollar, sensor based, computer dispatching system, Cyprus Pima Mining Company has installed a home¬made analog computer. The device is used in conjunction with a standard radio-dispatching system; it is inexpensive and very simple to build and operate. It enables the dispatcher to make near opti¬mum dispatching decisions and to identify all off schedule haulage trucks. Since installation, Cyprus Pima has experienced significant increases in pit productivity.

Jan 1, 1977

By Dean E. Albon

In the late 1940's and early 50's in southern Illinois, the usual open pit blasting in the coal field consisted of one or two rows of churn drilled vertical holes being shot with instant electric blasting caps. The entire shot detonated at one rime. In southern Indiana and Ohio most mines were drilling horizontal holes and they too were primed with instant EB caps. During the ten years from 1355 through 1965 many changes occurred in drilling and blasting methods. The churn drill in southern Illinois and the horizontal drill in Indiana and Ohio were replaced by the rotary vertical drill. The ammonia dynamites and liquid oxygen explosives were replaced by ANFO. The elctric blasting cap in the hole was replaced by a detonating cord down line and detonating cord trunk lines made the connections between holes and rows of holes. Host open pit mining was in areas far enough from town that the noise and vibration from blasting was, if not ignored, at least tolerated. During the 1960's open pit mining expanded to account for nearly 50% of the coal produced. Mines came closer to town and towns expanded along the highways with suburban homes and mobile homes. The mines began receiving complaints about the noise and vibrations from blasting operations.

Jan 1, 1976

By S. K. Kawatra

In most operating coal-cleaning plants, a significant amount of pyrite is recovered in the froth during flotation of high-sulfur coal. Reducing the pyrite recovery first requires that the primary recovery mechanism should be Identified, as different measures are required for reducing entrainment, locked-particle flotation, or true hydrophobic flotation. In this paper, evidence is presented which suggests that hydrophobic flotation is not an important mechanism for recovery of liberated pyrite from freshly-ground coal when the collector is a neutral oil, and that the bulk of the floated pyrite occurs either as a result of simple entrainment or by mechanical locking with floatable coal particles. Column flotation results are also presented which show that significant sulfur reductions can be achieved by reducing levels of entrainment.

Jan 1, 1992

By T. Gupta, T. Ghosh

"Rare Earth Elements (REEs) and their compounds are essential for numerous modern high tech applications such as renewable energy technologies, catalysts and defense applications. The destabilization of REE pricing owing to the global demand and supply deficit has forced many countries to re-evaluate the possibility of indigenous production of REEs. Cost effective and eco-friendly opportunities are being widely explored for extraction of REEs from non-conventional mineral sources such as coal and coal byproducts to stabilize the supply chain. Coal from Central Alaska (Healy Coal Mine) and Southern Alaska-Cook Inlet (Wishbone Hill) province have been found to possess elevated REE concentrations as compared to average world coal estimates. The objective of the study is to enrich the REEs in the fine size fraction (-75 Microns) from Healy and Wishbone Hill by froth flotation technique. A Box-Behnken design was applied for modeling and optimization of some operating variables on the flotation to maximize REE enrichment. The variables studies were frother dosage, pulp density (% Solids) and collector dosage. Experiments were carried out using a statistical design and the main and interaction effects on response variable was evaluated by analyzing 3D response surfaces. Based on the experimental results the optimum flotation conditions for maximum REE enrichment in the froth fraction was obtained at 4.2% Solids and 32.7 ppm of frother dosage for Healy coal sample and 10% Solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic equation for modelling and optimizing the response variable is found to be independent of collector dosage for both the coal samples. INTRODUCTION Alaskan coal deposits are distributed in three major coal provinces and are in Cretaceous and Tertiary rocks. The climate, vegetation type and sedimentation process has attributed to low sulfur content (averaging 0.3 percent) in Alaskan coals compared to other coal deposits found across the globe. In Central Alaska-Nenana and Southern Alaska-Cook Inlet coal province coal resources are contained in Tertiary rocks while bulk of the Coal resource in North Slope coal province is contained in Cretaceous and Tertiary coal bearing rocks [1]. Coals from Central Alaska- Nenana (Healy) and Southern Alaska-Cook Inlet province (Wishbone Hill) have been found to possess elevated concentrations of critical REEs as compared to the amounts present in world coals (Figure 1). The Wishbone Hill deposit is considered a relatively small deposit, with about 14 million tons of identified reserves, compared to Healy which has over 500 million tons identified [2]. The REE concentrations up to 286 ppm and 524 ppm on ash basis have been reported by Gupta et al. in 2016 with elevated concentrations Ce, La, Y and Nd which are expressed to be of critical importance by US Department of Energy. Accordingly, the two coal samples possess the potential to be used as a REE resource in the near future under favorable socio-economic and geo-political scenarios. [3, 4]"

Jan 1, 2017

By J. L. Yordan, J. Kortmeyer, I. Yildirim

Talc is used to remove stickies from pulp during paper recycling processes. It is well known that the interaction is controlled by the surface chemistry at the talc/water, sticky/water and talc/sticky interfaces. If the interfacial tensions are known, one can calculate the free energies of interaction and hence predict whether the stickies can be removed by talc. In the present work, the surface tensions of several different talc samples were determined using the acid/base theory. The information was then used to determine appropriate interfacial tensions, which in turn were used to determine the free energy of interaction between talc and stickies. It was found that the calculated free energies are much more negative than those between the stickies and other minerals such as calcium carbonate, bentonite clay and kaolin clays.

Jan 1, 2002

By Gabriel K. Nzulu, Lars Hultman, Per Eklund, Martin Magnuson, Abu Yaya, Prosper M. Nude, Hans Högberg

This study aims to identify individual elements and to gain an understanding of the surface reaction mechanisms, as well as the properties of precipitated pyrite particles observed during the hydrothermal formation of an ore deposit. A combination of X-ray diffraction (XRD), air annealing in a furnace, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray photoelectron spectroscopy (XPS) was applied to investigate the crystal structure and identify the individual elements, permanence, transformation and chemical/electronic properties of such pyrite.

Jun 1, 2024

By Bruce Hebblewhite

This paper focuses on the recent achievements and practices developed through the Minerals Tertiary Education Council (MTEC) initiative of the Minerals Council of Australia (MCA), in conjunction with the three partner universities involved in mining engineering education – University of New South Wales (UNSW), West Australian School of Mines, Curtin University (WASM), and University of Queensland (UQ). The collaboration between these partner universities and industry has led to the development of shared course material, cross-institutional teaching arrangements, and development of a number of flexible, distance-based delivery programs. The paper will then move on to future initiatives. Importantly, the exciting challenge is the future initiative planned to cement this collaboration by the formation of a “virtual” national school of mining engineering – Mining Education Australia (MEA). This will provide a common 3rd and 4th year program to all three universities from 2007, involving innovative teaching and learning arrangements, greater student exchange potential and a more significant input by industry into the education process. Such an initiative is not without its challenges, and has a long way to go, before becoming a reality. However, it offers greater attractiveness and marketing potential to prospective students, as well as economic efficiencies, whilst delivering a better quality, and hopefully greater quantity of graduates to industry. It can also form a launching platform for a much greater level of international collaboration, through a proposed International Mining Education Network (IMEN) which is currently being floated amongst a number of international educators.

Jan 1, 2005

By Thomas B. Faddies

The Trixie mine is located in the East Mining District. Since production began in 1970 over 450 000 tonnes of ore grading 239 grams of silver, 6.9 grams of gold, and 1.2% Cu have been mined from veins in Cambrian Tintic Quartzite. Detailed geologic mapping and extensive sampling are essential for compiling the data base required for efficiently developing and mining known reserves as well as planning exploration and development work. Although the basic techniques used by the geology group at the Trixie were developed many years ago, the reduced activity in underground precious metal mining in the U.S. have made these techniques less familiar to many presently active geologists. The increased activity in precious metals search and exploration again offer cause for the application of these techniques as a prerequisite to efficient exploration, development and production.

Jan 1, 1983

By N. T. Lowe

The National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory (SRL), investigated a means to evaluate the potential impact of surface conditions above underground mines on emergency response activities. Recent events have highlighted the need to conduct critical emergency operations on the surface above underground work areas. Accessibility and usability of the surface, such as the ability to drill holes or deploy seismic monitoring or through the earth communications systems, are an important consideration for emergency response planning. This paper identifies critical surface conditions such as: surface waters, valley fill, highways, railroads and significant structures that must be considered in emergency response planning and in the conduct of emergency operations as they relate specifically to the seismic detection of trapped underground miners. Results of case studies indicate a need to consider the impact surface conditions may have on emergency response capabilities.

Jan 1, 2009

By O. MacIntosh

The Round Mountain gold mine, located 90 km (55 miles) north of Tonopah, Nevada began large-scale production in 1977. During 2008 Round Mountain Gold Corporation (RMGC) relocated the primary crusher facility approximately 300 meters (1,000 feet) to make room for the next phase of open pit mining activities. This facility was installed in 1988 and used a log-crib retaining wall and dump pocket RMGC selected Hilfiker Retaining Walls and Collins Engineers, Inc. to provide design and materials for a new 17 meter (56 feet) high Mechanically Stabilized Embankment (MSE) wall to support the haul trucks at the new location. The construction contractor was EarthTech West Ltd. of Norwood, Colorado. An MSE wall with a cast-in-place concrete face was chosen as a durable, yet less expensive alternative to the reinforced concrete dump pocket that was originally designed for the project. The arrangement of the MSE wall is of an unusual configuration to meet a variety of operational and maintenance requirements. This paper outlines the selection process, design, and construction of the MSE wall.

Jan 1, 2009

By Burke Trafton

An earlier paper1 introduced a rapid solution for mine ventilation network problems, employing the digital computer. In this paper, refinements and additions to the computer program which expand its scope of application and a solution to a ventilation network having a coal-mine configuration are presented. Specifically, the revised program--written in FORTRAN for the IBM 7074 computer in Penn State's Computation Center--is applicable to any mine ventilation network employing natural splitting and having its fan located externally. It accomplishes the following; 1. Distributes an assumed total quantity of air flow among all air- ways of the network, performing iterations until an acceptable level of error is attained and the flow in each airway is known. 2, Computes the pressure drop (head loss) in all airways and the overall network and mine head losses. 3. Determines the operating point for the mine and a given fan, adjusting all air flows and head losses to the actual values.

Jan 1, 1964

By C. Laughton

Construction of a Deep Underground Science and Engineering Laboratory(DUSEL) is proposed under the auspices of the US National Science Foundation(NSF). DUSEL will provide scientists and engineers with a research facility capable of supporting a broad spectrum of fundamental and applied research deep in the earth’s crust. Research partners are physicists, biologists and geoscientists. DUSEL research calls for the construction of a network of shafts, tunnels and caverns that will provide laboratory facilities at depths of up to approximately 2 kilometers. The Project is still in the planning stages but, the initial experimental program is taking shape and conceptual designs have already been developed at two hard rock mine sites. This paper discusses the overall program and key engineering tasks being developed to support the construction of deep, large-span caverns. These caverns will house a new generation of physics experiments. As currently scoped, the experiments call for the excavation of permanent caverns with spans of up to 60 meters, sited at depths in excess of a kilometer.

Jan 1, 2007