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The surface of chalcopyrite was studied in situ in aqueous solution by an atomic force microscopy (AFM). The AFM images showed that some absorbate in patches was detected on the mineral surface, after the chalcopyrite sample was soaked in 5x10-4M potassium ethyl xanthate (KEX) solution at pH 11 for 10 minutes. These patches increased in size with time elapsing. At the same time, as shown by the obtained AFM force curves, the adhesion between the AFM tip and the substrate increased greatly due to the adsorption. Rinsing with ethanol removed the absorbate from the chalcopyrite surface, as well as the big adhesion observed in KEX solution.

Jan 1, 2010

By Edwin G. Johnsen

Underground mining is relatively safe today, but no technique or equipment is completely fool proof and 100% reliable. The only sure way to prevent accidental death or injury to underground workers is to remove them completely from the hazardous environment. This alternate approach to underground work is now feasible. Tunnelling and mining systems can be built that could be remotely controlled by men operating consoles in a surface control room. This concept, called a teleminer, would use recently developed remote control technology to remove man from underground work but still give him the capability to remotely operate mining and excavating equipment as if he were actually in the working area. It is appropriate to present this concept in the session "Environmental Controls" because the rationale for environmental control in underground areas can be significantly modified if man is excluded from the underground operation. The development of teleminers cannot only reduce or eliminate most of the requirements for conventional environmental control, but it can also create new and powerful techniques for rapid tunnelling and excavation. TELEMINER CONCEPT The concept of remotely controlled mining machines is neither new nor untried.(1)(2) Conventional remotely controlled mining equipment employs the standard techniques of extending the controls of the equipment to a remote console. For example, the rotary cutters on a remotely controlled tunnelling machine are started or stopped by a human operator turning a switch on the remote control console.

Jan 1, 1997

By Robert P. Bell, John T. Waggoner

The Metropolitan Water District of Southern California is designing new outlet facilities for Lake Mathews, including a junction shaft, connecting tunnels, and an ear-shore outlet tower. Since Lake Mathews must remain operational during construction, groundwater inflow potential is a concern. This paper describes the challenges and methods used to investigate rock mass and groundwater conditions at an operational reservoir, where offshore and onshore geotechnical exploration was performed. Several investigative and analytical methods were used to characterize rock mass and groundwater conditions, including rock coring, downhole geophysical and video surveys, hydraulic conductivity testing, automated groundwater level monitoring, and laboratory testing.

Jan 1, 1999

By Santhanam Sundaram

The potential for the utilization solar energy for the production of industrial process steer in mineral processing industries is discussed briefly. To advance the technical and economic feasibility of solar-thermal systems applications, U.S. Department of Energy has funded several projects. NL industries of Newberry Springs, California is one among them and has been chosen as a case study. The NL Industries solar system consists of 950 square meters of Del, single-axis, tracking, parabolic-trough, concentrating collectors. It was designee to produce a portion of the 420°. 530°k. steam utilized in a trying operation reduce the moisture content of hectorite ore from 10 percent to 4 percent. (Hectorite is an hydrous magnesium silicate which, when refined, is of significant commercial interest because of its applications in various chemical and food processes.) is estimated that implementation or this solar system could result an annual savings of 3.545 billion KJ ,3.360 billion BTUs), or the equivalent of 90 cubic meters (600 barrels) of oil and a net reduction of 1,860 kilograms (4100 pounds) of air pollutants annually. The technical, economic and institutional issues encountered in the course of this project are also discussed. Finally, the impact of the commercialization of solar energy applications in mineral processing industries is evaluated.

Jan 1, 1981

By T. Ruff, J. Steele

The lack of visibility near earthmoving equipment results in an average of five fatalities in U.S. surface mines each year. These accidents occur when a piece of equipment either strikes another vehicle or worker, or travels over the edge of an embankment. Researchers at the National Institute for Occupational Safety and Health have evaluated off-the-shelf proximity warning systems that sense obstacles near the equipment and provide an alarm to the operator. Limitations of existing systems have necessitated the development of new systems designed specifically for mining equipment, including a GPS-based proximity warning system and a computer-assisted stereovision system.

Jan 1, 2004

By L. Yan, T. Lutz, J. Noll

"Mine disasters, such as fires and explosions, can create a hazardous atmosphere due to the generation of carbon monoxide (CO). After a mine disaster, contaminated mine air can enter the refuge alternative (RA) as miners enter. Most built-in-place (BIP) RAs use an air delivery system to provide an unlimited supply of breathable air through a borehole which also serves to purge contaminants. In order to determine what levels of contaminants enter the RA, researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted testing in NIOSH’s Pittsburgh Experimental Mine using groups of 5, 15, and 30 subjects entering the RA. The experiment used sulfur hexafluoride (SF6) as a tracer gas that was released into the air outside of the BIP RA to establish a uniform concentration. After the human subjects entered the BIP RA, the SF6 levels inside the RA were measured to quantify how much of the tracer gas entered the BIP RA. In tests conducted while the borehole air supply was left off as test subjects entered, interior contaminant levels were less than 3% of the exterior concentration. In tests conducted with the borehole air supply activated as test subjects entered, the interior contaminant levels were measured at less than 2% of the exterior concentration. Considering a mine disaster can result in 10,000 ppm of CO in the mine atmosphere, these percentages indicate that unhealthy CO concentrations that may lead to headaches, dizziness, and loss of judgement can occur in a BIP RA. This information will help mines make decisions concerning air locks, air delivery systems and a determination if purging mechanisms are necessary. INTRODUCTION The Mine Improvement and New Emergency Response Act of 2006 (MINER Act) was enacted in the wake of three mine explosions/fires that claimed 19 lives that year. Intended to help improve underground coal mine accident preparedness, the MINER Act includes provisions that target mine safety issues in areas such as emergency response planning, adoption of new technology, training and education, and enforcement of mine safety standards (MSHA, 2006). Section 13 of the MINER Act specifically directs the National Institute for Occupational Safety and Health (NIOSH) to provide for research into the effectiveness and viability of RAs for underground coal mines. This mandate culminated in the 2009 adoption of changes to the 30 CFR mining health and safety regulations, requiring underground coal mines to provide RAs capable of maintaining a life-sustaining environment for persons trapped underground. Such RAs can be either pre-fabricated or BIP shelters. The regulatory changes also include provisions establishing requirements for Mine Safety and Health Administration (MSHA) approval of RAs and their components, and among these provisions are numerous criteria for providing a safe, breathable atmosphere within RAs."

Jan 1, 2018

By J. J. Kellar, W. M. Cross, H. Du, C. D. Struckman, D. A. Boyles

Silane coupling agents have been used in the filler industry for years. One particularly unique feature is the ability of the coupling agents to enhance the adhesion between filler and polymer matrices. This paper will review the use of coupling agents for polymer matrix composite applications and discuss a new approach to coupling agent chemistry, namely, direct formation of a silicon-carbon non-hydrolyzable linkage between glass and coupling agent. The grafted silane monolayers were evaluated by infrared spectroscopy to ascertain their surface coverage and relative stability. Finally, composite specimens were fabricated and their mechanical properties were compared with traditional silane coupling agent treatment.

Jan 1, 2003

By D. A. Poukhovski

Two integral components of the 30 CFR 48 training requirements mandated for new miners, newly employed experienced miners, and the annual refresher training of all miners are hazard recognition and prevention of accidents. In these categories, instruction shall include the recognition and avoidance of hazards present in the mine, and a review of accidents and their causes. Unlike instruction preparation for fact-based material, program development for hazard recognition places a particular challenge before safety-training specialists because they are often limited in their ability to adequately gauge the trainees' levels awareness prior to training. Further, they must also assure that the training is relevant, and it is presented in a thought-provoking manner. Computer-based instruction is particularly well suited for assisting trainers in developing hazard-recognition topics because it can be used in pre-training and post-training modes for assessment of training effectiveness, in addition to use as a presentation tool. Therefore, this paper will present a recent approach developed at Penn State to apply this technology for assessment and instruction of accident prevention through hazard recognition, with an application prepared for surface coal mines.

Jan 1, 1997

By Eric Jackson

The presentation describes the operation and field test results of a seafloor massive sulphide prospecting system. The prospecting system is deployed from a work-class ROV, and it features a new and innovative electromagnetic ocean floor conductivity sensor. It also includes magnetometers, a multibeam sonar, and subsea cameras. The prospecting system has been used in two exploration campaigns - one in the territorial waters of Papua New Guinea (PNG) in 2007 and again in 2008 in both PNG and Tonga waters. The 2007 campaign used the prototype sensor, and the 2008 campaign used a Mark II version. Correlations between drill core samples and EM conductivity results are excellent. New prospecting system data will be used to help plan future core drilling locations. The presentation discusses the principle of operation of the EM conductivity sensor, discusses improvements made in the EM sensor and the overall prospecting system, and shows exploration results. Keywords: seafloor massive sulphide, geophysics, ocean floor, subsea, electromagnetic, conductivity, magnetometer, multibeam, core drilling

Jan 1, 2008

By J. Hanna, I. J. Anazia

The Mineral Resources Institute (MRI) has developed a unique process for selective fatty-acid flotation of phosphate minerals from siliceous ores. The process takes advantage of preferential adsorption (over silica surfaces) and high reactivity of fatty-acid collectors toward apatite under slightly acidic conditions (pH 5 - 6.5). The process was successful in upgrading various Florida and North Carolina phosphate samples containing 7.7% to 15.3% P205 and 62.3% to 77.2% siliceous gangue (Insol). The resulting concentrates assayed 28.1 % to 33.1 % P205 and 4.1 % to 9.9% Insol, with high P205 recoveries of 81.8% to 92.2%. Depending on the degree of surface contamination of the silica particles in the flotation feed, one or more cleaning steps, with or without sodium silicate, would be required to achieve higher-grade phosphate concentrates.

Jan 1, 1994

By R. C. Emmett

In extractive metallurgy, separation of insoluble solids from solutions is an important economic factor in almost all flow- sheets. This separation step can employ sedimentation, filtration (vacuum and pressure), or centrifugation. Since practically all systems require a relatively complete separation, multiple unit, countercurrent thickeners or vacuum filters are generally used.

Jan 1, 1974

By I. G. Ediz, D. W. Dixon, W. M. Fidler

In this paper a new method for the arresting of tunnel explosions is presented. In the proposed technique, the on coming explosion is detected by a pressure sensitive device by a pre-determined rise in static pressure. The sensor then triggers a mechanism which causes the explosion door to be closed in a specially constructed concrete barrier zone. The doors are of a special construction and consist of perforated steel plates that allow part of the blast wave to be transmitted but do not allow the passage of the flame. A number of design parameters have been identified, including: the likely amplitudes of the transmitted/reflected pressure waves that would govern the explosion door pressure loading; thickness of the perforated steel packages; perforation dimensions; heat transfer across the door and other factors.

Jan 1, 1995

By H. H. Murray

New and improved benefication techniques are available to allow the production of clay minerals of exceptionally high purity. This is particularly true for kaolins and smectites. Wet processing techniques including particle size separation, high intensity magnetic separation, chemical leaching, flotation, and selective flocculation are described and results and applications are discussed. The blending of clay minerals with other minerals provide opportunites to make special ceramic materials such as cordierite and other minerals which have very special ceramic properties including low heat expansion, high fired strength, low absorption, and other desired qualities.

Jan 1, 1989

By M. R. Rosen

CARBINDER Polymer 498 is a liquid organic taconite binder which significantly improves fired compression in both fluxed and acid pellets. It has been used commercially in both shaft and straight grate furnaces. This new binder produces an unusual wicking phenomenon during balling wherein the rate of movement of interstitial water is accelerated to the surface of the balls. The phenomenon is proposed to be responsible for the significant improvement seen in fired compression. This paper presents information as to the effect of CARBINDER Polymer 498 on green ball and fired pellet properties. It also describes the wicking phenomenon and discusses a reversal in the normal balling operation procedures required for successful agglomeration.

Jan 1, 1988

By V. A. Temeng, M. Owusu-Tweneboah, K. Awuah-Offei

The mining industry has long recognized the value of dispatch systems in open pit mines as they reduce load and haul costs. Over the years, researchers have proposed many dispatch systems with various limitations and advantages. The simplest dispatch algorithms are the so called 1-truck-for-N-shovels dispatch strategy. These algorithms are limited by the fact that their objective functions do not consider all the objectives of a mine and cannot be applied to all possible truck-shovel configurations. They are also myopic in nature. However, they are simple and computationally efficient and do not require occasional updates of the upper stage problem as required in multi-stage dispatch algorithms. In this work, an agent-based truck dispatch algorithm that conceptualizes trucks as intelligent agents that make autonomous dispatching decisions to maximize their utility is proposed. The advantages of this algorithm includes utility functions that encapsulate all of management’s objectives and agent’s with broad situational awareness. They are also more suitable for autonomous trucks. We evaluate the new algorithm against a simple 1-truck-for-N-shovels dispatch strategies using discrete event simulation. The simulation results show that the new utility function has significant advantages over 1-truck-for-N-shovels inspired utility functions. Future work will incorporate adaptive behavior into the model via reinforcement learning algorithm. INTRODUCTION In an attempt to optimize truck shovel operations in open pit mines in order to reduce the cost of haulage operation, which according to (Alarie and Gamache, 2002) is estimated to be about 50-60% of the total cost of mining, several effective and efficient strategies have been developed. Optimizing truck haulage systems in an open pit mine is one of the greatest challenges of mining engineering and has been the subject of many research projects. It is important that haulage systems are designed to be efficient, in order to minimise haulage cost, improve profitability and increase the total mine value. Although optimizing the number of trucks required in the operation of open pit mines can help reduce the cost, an effective and efficient truck dispatching system add value by ensuring that the available trucks are used efficiently. With truck dispatching systems, the trucks are normally dispatched between the crusher and dumping station (e.g. waste dumps and stockpiles), and the shovels in order to maximize the total output, obtain grades targets, reduce fuel consumptions and other objectives. Truck dispatching, which can have one or more objectives, is typically subjected to certain operational constraints such as truck and shovel capacities, empty and loaded trucks speed, among others. The problems associated with truck dispatching was first mentioned by Dantzig and Ramser (1959) after they made an attempt to determine the optimum routes of a fleet of delivery trucks between bulk terminals and a service stations. The problem occurs in several industrial systems besides mining (Alarie and Gamache, 2002; Gendreau et al., 2006; Rego and Roucariol, 1995). The dispatching problem, also referred in literature as the vehicle routing problem, has seen a number of modifications and extensions with Bertsimas and Ryzin (1991) presenting a dynamic and stochastic vehicle routing problem, and Ralphs et al. (2003) also adding to the original concept, the concept of vehicle capacity routing.

Jan 1, 2019

By M. S. Klima, M. Fofana

The use of a laboratory-scale magnetic fluid-based separator for coal separations was examined. A Frantz laboratory magnetic separator was modified by fabricating new pole pieces of the appropriate geometry to provide the proper magnetic field gradients. Two separation chambers, which were constructed of Plexiglas, were designed to fit between the pole pieces. A commercially available, water-based, ferromagnetic fluid was used as the separating medium. The separating density was changed by varying the current intensity of the electromagnet coil. Both batch and continuous separations were made using 0.59 x 0.50-mm and 0.18 x 0. 15-mm coal. The results are compared to those obtained using organic liquids.

Jan 1, 1998

?Energy-related systems: wind, solar, electric are typically materials intensive. As new technologies are widely deployed, significant quantities of the elements required to manufacture them will be needed. However, many of these unfamiliar elements are not presently mined, refined or traded in large quantities, and, as a result, their availability might be constrained by many complex factors. A shortage of these ?energy-critical elements? could significantly inhibit the adoption of otherwise game-changing energy technologies. This, in turn, would limit the competitiveness of the U.S. industries and the domestic scientific enterprises and, eventually, diminish the quality of life in the US.? -Energy Critical Elements: Securing Materials for Emerging Technologies?- American Physical Society, 2011.

Jan 1, 2012

By Xinming Lu

In this paper, we use a new kind of fan charateristic curve instead of the common quadratic function, and give the existence and the uniqueness of the solutions to the ventilation network controlling equations, so that the existence and the uniqueness of the solutions for the natural air distributting problem can be conveniently given. We also give a conjugate gradient method with the global convergence to solve the equations having the unique solution. Because we adopt a very efficient technique of one dimensional search (or linear search) in this method, the method can quickly solve a lot of problems, especially in large scale problems. The second part of this paper is the establishment of the model of the constrained quadratic programming for the measurement adjustment of mine ventilation network. We give the algorithm to solve this model as well. The two algorithms given above have been realized in the mic-computer MC-68000 with Fortran codes, and the numerical results are satisfactory.

Jan 1, 1991

By D. R. Nagaraj

The chemistry and structure-activity relationships for four new classes of sulfide mineral and precious metals collectors developed recently are discussed in this paper. These collector classes are alkoxycarbonyl alkyl thionocarbamates and thioureas, dialkyl (or diaryl) monothiophosphates and dialkyl monothiophosphinates. The main emphasis will be to highlight the differences between collectors and their affinities for various minerals on the basis of data on kinetics of adsorption on pure minerals, natural ore flotation and microscopy of flotation concentrates. The mechanism of interaction of these collectors with sulfide minerals is also discussed with the available data on the FTIR and solution chemistry studies.

Jan 1, 1989

By Harry C. Oussoren, James C. Miles

A new seven kilometer long subway line is being constructed through dense glacial soils under a major thoroughfare in Toronto. Eductor, deep well and vacuum wellpoint systems are being used to lower the water levels by as much as 16 metres for the construction of the twin tunnels and associated structures. The design and performance of the dewatering systems will be described. Unanticipated difficulties and their solution will be presented.

Jan 1, 1999