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By P. Kolettas

The development of novel methods for the investigation of the subsoil contributes to the improvement of geotechnical research, enhances the obtained geotechnical characterization and may reduce the investigation cost by reducing the number of required tests. Non-destructive testing methods, performed either in situ (i.e. electrical tomography, seismic refraction, etc) or in the laboratory can provide initial data and perhaps estimates of rock/soil properties. This study focuses on the development of rock material properties and/or characteristics based on non-destructive laboratory testing of a number of stones, ranging from porous (bioclastic) limestones to impervious marbles. Seismic velocity measurements as well as attenuation signals were digitally recorded using a digital oscilloscope. Data were processed using a novel technique of spectral analysis available through special Matlab packages employing Fourier transform methods. More specifically, the NFFT (Non Equispaced Fourier Transform) transformation was applied to seismic waves traveling through the subsoil using the Autosignal program (by Seasolve) and the Specgramdemo program included in the Signal Analysis toolbox of Matlab 6.5 (Mathworks). Results indicate a definite relationship between the frequency content of the signal and the rock type as well as the degree of saturation of the specimen.

Jan 1, 2008

By M. S. Celik, A. Aslanbas, B. Pehlivanoglu, R. Asmatulu

The principal impurities in some feldspar ores are titanium and iron, which impart color and degrade the quality of the ore. Mineralogical investigations indicate that, while titanium originates mainly from rutile with small amounts of sphene, iron originates mainly from mica minerals. Fatty acids, particularly oleic acid, are extensively used, with reasonable success, in the flotation of colored minerals from feldspar ores. In this study, potassium oleate, oleoyl sarcosine and hydroxamate were used to float colored impurities both before and after magnetic separation. Oleoyl sarcosine is found to exhibit better results compared to other reagents. Magnetic separation followed by flotation is found to produce a feldspar concentrate of superior grade.

Jan 1, 2002

By R. Bhaskar

Although the health effects of airborne dust in underground coal mines are well recognized, a lack of understanding remains about the fundamental mechanisms of dust generation, transportation, deposition and dust-lung reaction. This study was intended to contribute to the understanding of dust transportation and deposition mechanisms in underground mine airways. Data from in-mine experiments carried out under controlled conditions in a straight section of a longwall panel with three different airflow velocities and two different types of coal dust (bituminous and semi-anthracite) were used to determine the turbulent deposition rate of dust particles. Measurements of ambient dust concentrations and deposition along the mine airway were obtained and the total dust deposition velocity (rate) was calculated. The deposition velocity of turbulent diffusion was estimated based on the experimental data and theoretical equations. The effects of airflow velocity, particle size, particle density and distance from the dust source on gravitational, turbulent and total dust deposition are discussed along with related conclusions.

Jan 1, 1995

By Robert R. Dorfler

AMPS[. has completed a rationed grinding ball test in a 2.93 m x 2.93 m ball mill at Climax Molybdenum Company. The test consisted of purging the ball distribution formed by charging 100%, 76 mm carbon steel balls with a distribution formed by charging 50% 76 mm and 20% 51 mm alloy steel balls. The resulting change in ball surface area yielded improvements in both tons ground and fineness of grind with a significant reduction in total ball consumption. This paper summarizes preliminary studies leading to the plant test, grinding efficiency results, and future plans to optimize the ball charge.

Jan 1, 1981

By G. Whitney, J. Steiner

Introduction The Summitville Mine located in southwestern Colorado is an example of the potential impact that natural weathering and mining activities can have on environmental quality. Acid rock drainage and metals leaching from active and historic mine districts are a major environmental problem facing the mining industry today. Sulfide ore exposed naturally or during mining operations has the potential to produce leachates that contain high concentrations of dissolved metals. These leachates can affect the quality of plant and animal health in surface water used for agriculture, recreation and human consumption. Pintail Systems has developed biological processes for detoxification of cyanide in heap-leached spent ore and process solutions. During application of spent ore cyanide bio-detox processes we have also observed a substantial reduction in many of the leachable metals in biotreatment solutions. These field observations of soluble metal reduction led us to propose that metal bio-mineralization should be a secondary treatment goal of spent ore detox in Focused Feasibility Studies (FFS) for the Summitville Mine. In the FFS (described in a companion paper) for Summitville, spent ore from the heap leach pile (HLP) was loaded into PVC test columns (six inch X ten foot) and was leached with bacteria/nutrient solutions. Two treatment designs were studied: a standard percolation leach (aerobic) and a saturated leach design where the ore was saturated with the heap leach solution to which bacteria and nutrients were applied in a continuous biotreat leach. The bacteria for all column treatment tests were isolated from the spent ore at depth through the Heap Leach Pile (HLP) in the saturated and unsaturated zones. Bacteria isolated from the heap material were tested for cyanide oxidation capacity and were submitted to a bioaugmentation program to improve reaction kinetics and metals tolerance. The final treatment population consisted of several distinct species including aerobic heterotrophs, facultative anaerobes and sulfate-reducing bacteria. The remineralization of soluble metals was observed through a decrease in copper in column leachate solutions and the formation of observable mineral products on ore surfaces in the columns. Several of the tests were run in clear PVC columns to facilitate observation of mineral formation. The column ore contents were photographed before, during and after the biotreatment process which ranged from 10 to 20 days for each test column. Ores were collected from each column after the treatment was complete and were submitted for SEM and TEM study at two laboratories - the USGS SEM Laboratory in Denver, Colorado and the City College of New York SEM laboratory. Treatment Process Description Numerous species of bacteria, fungi and yeasts are capable of accumulating many times their weight in soluble metals. Both living and dead biomass are effective in removing soluble metals from waste streams containing gold, silver, chromium, cadmium, copper, lead, zinc, cobalt and others. Soluble metals may also be immobilized in soils by natural or engineered biomineralization reactions. Several commercial processes using biological reactions are being applied on an industrial scale for metal remediation. Bacteria found in natural and extreme environments have developed a wide variety of metabolic functions to adapt to these environments. These natural microbial functions contribute to global mineral cycling that continuously forms, transforms and degrades minerals and metals in the environment. Biomineralization is described as a surface process associated with microorganism cell walls where the remineralization occurs. The biogeochemical activities initiated by microorganisms in ores, soils, surface and groundwater environments can dominate the formation and transformation of those mineral environments.

Jan 1, 1995

By Arthur P. Nelson

In opening, I want to thank the program committee and members of the Society of Mining Engineers of AIME for the opportunity to speak to you. Various chapters of AIME this past year have expressed interest in the Federal Metal and Nonmetallic Mine Safety Act. We want to see that interest continue, because the reason for the legislation was the safety and health of the industry's workforce. The Department of the Interior was directed by the Congress to administer the provisions of the Act and is therefore held directly accountable for the success or failure of its intent. We intend to see it succeed. Among other things, the Act does provide for education and training under Section 15. This provision has been implemented and is expanding. However, the responsibility of my office is inspection and enforcement and that is my subject today.

Jan 1, 1973

"Outotec’s TankCell® e500 flotation cell was commissioned during 2014 at the Kevitsa Mine in northern Finland. The TankCell® e500 is the first cell in this size class (500m3) to be run in an operational duty and it has been working as the first rougher in the copper flotation circuit. Treating around 850tph with an average grade of 0.3% Cu the TankCell® e500 has run with an average copper recovery of 71% and an average enrichment ratio of 50. In addition the cell has proved to be very energy efficient, operating with a specific energy of around 0.4kW/m3 under production conditions. This presentation will provide a review of the installation and operation of the TankCell® e500 at Kevitsa and will summarize the results found in the published literature from the various testing campaigns conducted around the cell. INTRODUCTION The TankCell e500 was installed and commissioned at the Kevitsa mine in northern Finland in 2014. Post startup the cell was initially run for testing and optimization with various test campaigns undertaken. but was subsequently taken into a production duty (Mattson et al., 2015a). At Kevitsa the cell is run as the first copper rougher replacing the previous two copper roughers (both 160m3) in this duty. The unit is running at between 38-40% solids at a feed rate of approximately 850tph. Since operational the average copper recovery from this single cell has been around 71% copper. This is typically with an enrichment ratio of around 50 being fed with an average head grade of 0.3% copper. More details on the circuit configuration and production performance of the e500 at Kevitsa can be found in Mattson et al., (2015a) and Murphy et al., (2016). In addition through the optimization program with the use of a variable speed drive controlling rotor speed it was found the the e500 was very energy efficient under production conditions. During this work the cell was found to run at a specific energy of around 0.4kW/m3 which exceeded design expectations (Xia et al., 2015)."

Jan 1, 2016

By John R. Turney

MARY KORPI: Harry Hinds will be filling in for John Turney today. Harry is an exception to the industry these days, in more ways than one. He has worked for the same mining company for 33 years. That is something very few of us can claim. He is currently metallurgical superintendent for Homestake Mining Company in Lead, South Dakota. Harry is also the envy of many of us as he will be retiring this year and working on lowering that handicap! Harry will be discussing the "Role of Consultants."

Jan 1, 1998

By Michael Ferrell

The primary reason pigments are used in plastics is to impart a desired color to the plastic. Color is one of the more important assign considerations associated with today's market oriented society. Secondary reasons for adding pigments to plastics include: 1. Improved UV stability 2. Enhancement to selected physical properties 3. Changes in optical properties Pigments may be used at loadings as high as 20% or as low as .001%. Generally the loading levels are between 0.2% and 2.0%. Pigments may be added to the plastic either by the manufacturer of the plastic, or by the user of the plastic. If the customer buys material that is already colored, it is referred to as "pre-colored". If the customer buys uncolored plastic and adds colorants, the process is referred to as "in-house" coloring.

Jan 1, 1985

By T. Brady, J. Johnson, J. Whyatt, B. Pariseau, M. Stahl

An elastic-viscoplastic material model allows for time-dependent rock mass motion in proportion to excess stress above the elastic limit. The model produces rounded stair-step curves of displacement versus time that are similar to those obtained from recent borehole extensometer measurements made in the central portion of the Ross shaft pillar at the Homestake mine. The work in progress, including two- and three-dimensional finite element analyses using the UTAH2/3 codes, indicates that the model is a step towards more realistic safety and stability analysis, but that inclusion of rock mass damage may be desirable.

Jan 1, 2000

By Charles A. III Cravotta

Streamflow and water-quality data for the northern part of Swatara Creek, which drains a 112-km2 area in the Southern Anthracite Field of east-central Pennsylvania, indicate iron, copper, and lead, and to a lesser extent manganese and zinc, are transported with suspended particles during stormflow conditions. During stormflow conditions, concentrations of these constituents typically peak prior to peak stream stage as a result of scour and transport of streambed deposits. In contrast, sulfate is transported mostly as a dissolved ion. Concentrations of sulfate, specific conductance, and pH are inversely related to streamflow, indicating dilution and acidification during stormflow. This effect is attributed to the mixing of poorly buffered stream water having pH 6.0-6.5 with weakly acidic storm runoff having pH 4.0-4.5 and low dissolved solids.

Jan 1, 2000

By Ivano Andreis, Georgios Kalamaras, Mario Liti, Sebastiano Pelizza, Filippo Avesani

"THE SS640 AGRIGENTO-CALTANISSETTA PROJECT The Caltanissetta tunnel is part of the works for the construction of the second 28km-long maxi section of the SS 640 motorway of Porto Empedocle, from km 44 to the junction of Imera in Sicilian hinterland. Amongst other major infrastructure works, the €740 million ANAS (Italian national roads and highway administration agency) project consists of four twin tube tunnels three of which are being excavated by conventional means. The longest tunnel, underpasses the Caltanissetta city and has a length of 3.9km under a maximum overburden of 120m. The JV consisting of CMC of Ravenna and TECNIS SpA won the design & built tender in 2010. Construction started in early spring 2012 following the approval of detailed design and later on the approval of design for construction. THE CALTANISSETTA TUNNEL The Design Phase Tender design and detailed design foresaw the construction of 13.4m excavation diameter tunnels that were to be enlarged in a second phase to create, every 600m, 50m-long tunnel sections for emergency parking. During the design for construction project phase the JV proposed to replace the 13.4m tunnel with a 15.08 excavation diameter that incorporated apart from the two 3.75m wide lanes a 3.25m wide continuous emergency lane. This significant tunnel section modification was associated with better road safety conditions, simpler and safer construction procedures, better statics for the tunnel section while in terms of overall cost the solutions were equivalent.Geologic context The tunnel is located in the middle of the geologically known Caltanissetta basin that is intersected by various tectonic structures. The geologic context for the tunnel scale, was defined in collaboration with the University of Catania in early project phases. For almost its entire length the tunnel is excavated in the Terravecchia formation that represents the lower part of the stratigraphic sequence that was formed in the Tortoniano period of Miocene. The quite complex geological model is also characterized by the presence of the so-called Trubi formation that consists of clay and marl clay. Almost 90% of the tunnel traverses formations that are quite similar in terms of excavation behavior. Exception to this are thrust zones and a calcareous stretch of the alignment. This last segment has a length of 200m and was identified since the very beginning as a tunneling challenge due to the combination of very poor geotechnical properties and an important water load."

Jan 1, 2016

By J. L. Carr, A. K. Smith, C. C. Jobes, G. T. Homce

"Underground continuous mining machines pose a difficult safety challenge since their operators generally work in close proximity to these machines in very restricted spaces. Intelligent software for use with magnetic proximity detection systems has been shown to accurately locate workers around mining machinery in real time. Calibrating these systems requires the manipulation of a lot of data to determine the calibration constants. Researchers have developed software to analyze, convert, and visualize data acquired during this calibration process to more accurately model magnetic fields and their interaction with the environment. This paper details the background, development, and operation of the resulting application software focusing on the utility of the graphical user interface to visualize the magnetic field calibration data. The refined data developed by this process can then be utilized by the proximity detection system to more accurately identify the location of miners working in an underground mining environment. INTRODUCTION Roughly half of the electricity consumed in the United States is produced with coal, and roughly one-third of all US coal production comes from underground mines [1]. Over the last century underground mining health and safety has seen a continuous and dramatic improvement. However, machine-related injuries and fatalities continue to be a major safety concern [2]. Every year, hundreds of miners are severely injured while operating underground mining equipment, and 39 miners have been killed in striking/pinning accidents involving continuous mining machines (CMMs) since 1984. CMMs, such as the one shown in Figure 1, are large mobile machines that are used to mechanically cut coal in an underground mine. These machines weigh approximately 40 to 50 tons, have hydraulically articulated appendages, and are capable of moving at speeds up to six feet per second [3]. Modern CMMs are remote-controlled, yet the operator and other miners are often in close proximity to the machine. Recent research by the National Institute for Occupational Safety and Health (NIOSH) reveals that the locations workers take relative to the CMM are usually influenced by visibility requirements and safety concerns [4]. The Mine Safety and Health Administration (MSHA) estimates that at least 28 fatalities involving CMMs since October of 1984 may have been prevented with proximity detection technology [5]. MSHA further estimates that proximity detection could prevent 20% of all deaths throughout the industry [6]."

Jan 1, 2016

By C. L. Karr

Researchers at the University of Alabama have developed a method for producing fuzzy linguistic models of mineral processing equipment directly from engineering data. These fuzzy linguistic models rely exclusively on data collected from the processing systems being modeled and do not presuppose an understanding of the physics of the system. The fuzzy linguistic models use descriptive rules and explicit membership functions that provide a precise, nonmathematical description of the processing equipment. A genetic algorithm is employed to simultaneously select rules and tune membership functions used in the fuzzy models. The result is an extremely flexible approach to modelling that is applicable in a variety of linear and nonlinear systems. The effectiveness of this approach to modelling is demonstrated using a four-input, two-output model of a grinding circuit.

Jan 1, 1996

By Roger P. Ashley

The main problem in geochemical exploration for gold ore bodies in the 40 km2 hydrothermally altered area at Goldfield is to decide which of the many silicified ledges exposed are most likely to yield deposits with additional subsurface exploration. We conclude that the most efficient way to search for exploration targets is to collect rock samples from the ledges and analyze for the following elements in decreasing order of priority: gold, lead and silver, bismuth, and mercury. These elements form relict hypogene aureoles restricted to the ledges and are not appreciably redistributed during supergene leaching.

Jan 1, 1978

By William Gleason

Since 2004, Dave Kanagy has served as the executive director and chief executive officer of SME. In that role, he has worked with 22 SME Presidents, traveling the world to represent the Society. His prestigious one-million-mile status with United Airlines is a testament to these efforts. He has been to six of seven continents while leading the Society on a journey from a struggling association in 2004 to the largest and arguably the most influential professional mining society in the world. In the following pages, some of those past SME Presidents reflect on their time with Kanagy and paint the picture of a visionary leader who was willing to make the hard decisions for the betterment of the Society while remaining open to new ideas and opportunities. One of his first accomplishments as the executive director was to streamline the SME Boad of Directors from 29 members to nine, making it much more effective. With a keen financial sense, he was able to add value while cutting excess to expand the Society in every measure. As the leader of SME, Kanagy helped facilitate much of the Society’s growth and innovation as the world’s largest mining related organization. He has a B.S. degree in industrial education from the University of Maryland, an M.S. degree in technology education from Eastern Illinois University and is a certified association executive by the American Society of Association Executives. Under his leadership, several unique programs were created or advanced, including OneMine.org, the world’s foremost online mining research library. He enhanced legacy programs and increased collaboration with international organizations. Kanagy is the recipient of prestigious awards, including the Colorado Society of Association Executives’ Professional of the Year award and the Mining and Metallurgical Society of America’s Gold Medal award.

Feb 1, 2026

By R. B. Massy-Greene

Project engineering and development is a process of optimisation of capital, operating and financial costs, and extraction rates in the light of current and forecast economic conditions for the sale of the product. The aim of the process is to maximize financial returns to the sponsors (project owners) within many often conflicting constraints. Thus, the sponsor's engineering and financial staff have a common goal, with performance measured in financial terms. Consequently, each group must be aware of, and responsive to, the constraints imposed upon the other. For financial staff, the increasing size and complexity, and escalating capital costs of new ventures have required them to seek finance in larger amounts, and by non-traditional methods. In addition, senior management are requiring indications of the availability of finance as a pre-requisite to a decision to commence project development activities.

Jan 1, 1982

By Thomas P. Meloy

There is much interest in the automation of entire comminution circuits, At the present technological level it is possible to automate a circuit but to date it has not been done, To successfully automate a circuit, a number of problems must be solved. Not all of them are engineering problems. The purpose of this paper is to discuss some of these problems, as certain the implications of these problems and indicate solutions to them. In this paper the term "automation" is used loosely but in the popular sense. Namely, that a plant is automated if a computer is used to control the basic flow of the materials as well as setting the critical parameters in the process. Specifically, the discussion will concern itself with the control of comminution circuits from the dumping of the ore into the primary crusher until the final interface between the comminution circuit and say, the flotation mill in the case of a sulfide ore.

Jan 1, 1965

By R. E. J. Putman

The, principle purpose of applying control to any process is to improve -its profitability. Even when considering the impact of a plant on its surrounding ecology this is still, true, since the sanctions felt most immediately from violations of the regulations are the economic penalties or fines which result. 'Economic performance can be improved within a plant in several ways. Steps can be taken to cut the cost or quantity of resources (power, water, steam, reagents) consumed per ton of throughput. Alternatively the operation of the plant can be changed so as to increase product yield per ton of throughput. Or the cost of labor and plant overhead per ton of product can be reduced by raising the total 'throughput, assuming-that the increased amount of product can be sold for the same unit price. In designing a program to improve plant performance, all three routes should be borne in mind. To maximize the return on investment over a longer period, it is also desirable to set up a comprehensive plan of improvement, equipment being specified at each step in the implementation so as to ensure that it fits in with later requirements later implementation being either by means of modular additions or by having the necessary interfaces built into the original equipment. It is much cheaper in the long run to buy features which have been factory-installed, than to have to make provision for their later addition in the field. This paper examines some ways of improving plant performance by the application of various process control techniques using both analog and digital con¬trol equipment. A general philosophy of application is suggested and specific examples described.

Jan 1, 1972

By Egon Pohl, Friedrich Steinhäusler, Werner Hofmann

INTRODUCTION Anticipated increase of nuclear fuel production in the future coincides with growing concern about the occupational health risk of miners from inhaled radon decay products. As a consequence it has been suggested to even lower presently permitted exposure levels (NIOSH, 1980) and implement more stringent control on measurement programmes. Compliance with these regulations requires large investments in new or modified ventilation systems as well as in increased expenditure for staff and instrumentation for health physics operational monitoring. Since both costs are directly related to the overall ore production costs, this can have far reaching implications with regards to the economic feasibility of certain mining operations and consequently reduce estimates of low-cost minable ore reserves. In addition there is increasing evidence that the radon problem is not limited to the nuclear fuel cycle only, but can also represent a significant hazard to non-uranium miners. A key component in the cost-effective implementation of legislative control measures is the monitoring system employed. The choice of system is decisive for the total costs of installation and maintenance, manpower requirements and accuracy of nuclide determination. In the following operational specifications are defined for monitors in mining and milling environments. Different types of available instrumentation are discussed with regard to their suitability for practical radiation protection in underground mines, open cut mines and mills. ATMOSPHERIC CHARACTERISTICS Underground mines Radon in the air of underground mining operations is exhaled from surrounding rock surfaces, crushed material and, to a lesser extent, from water seepage. Whilst in uranium mines radon releasing ore bodies are generally localized in distinct areas, radon sources in non-uranium mines can be very dispersed throughout the system of mine tunnels. The ventilation scheme used influences the absolute atmospheric level of radon as well as the equilibrium conditions between radon and its decay products (factor F). In uranium mines mechanical forced-air ventilation is normally the only way to achieve and maintain legally required nuclide levels. This causes the F-factor to be rather low, e.g. in French CFA-mines F is of the order of 0.2 (Francois, Pradel, Zettwoog, 1975). At the same time the fraction of unattached radon decay products (fp) can increase due to the high air velocities employed. However, it is possible to find non-uranium mines with either natural draught ventilation only or assisted on demand by forced air ventilation during special operations or climatic conditions. Thereby the F-factor is more dependent on seasonal changes of temperature differences between outdoors and mine atmosphere and work routines. As a result F can cover a wide range from 0.02 to 0.95 (Steinhäusler, 1976). The use of filters or electro-precipitators in mine ventilation systems can modify the atmospheric characteristics twofold as it generally decreases the content of radon decay products, but at the same time increases the content of the unattached fraction fp . Average concentration levels of radon decay products are mostly lower in mechanically ventilated non-uranium mines than in equally ventilated uranium mines and are below 0.3 Working Level (UNSCEAR, 1977). However, some working places in non-uranium mines, specially with only natural draught ventilation can occassionally approach maximum permissible levels as defined for uranium mines (Strong, Laidlaw, O&apos;Riordan, 1975; Snihs, 1976; Sciocchetti, Scacco, Clemente, 1981). Open pit- and surface mines Radionuclide levels of radon decay products in the atmosphere of these mines are mostly too low to represent a significant inhalation hazard for miners, ranging typically from 0.03 to 0.1 Working Level (Steinhäusler, 1976). However, personnel using airpurifying respirators or working in cabins ventilated with filtered air can be exposed to a radon atmosphere with low value for the F-factor (F [<] 0.1) and high fp-value up to 80 % (Leach and Lokan, 1979). Mills Atmospheric radon concentration in crushing, grinding, drying and packing sections depends on the radium 226 content of the ore, ore storage methods and ventilation system employed. Providing adequate ventilation ([>] 2 air changes per hour) and control of dust production radon and its decay products represent only a minor problem (Saconney, 1979). MONITORING OF OCCUPATIONAL EXPOSURE Objectives Operational monitoring of the working places provides information on: - confirmation of appropriate control of the routine mining methods employed - indication of abnormal conditions. Although this type of monitoring enables the location

Jan 1, 1981