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By Larry D. Wayland

Almost 100 sedimentation ponds were conceptually designed for a large surface mining study area in northeast Texas. An approximate procedure was developed to economically estimate construction quantities in order to predict surface water control costs. This procedure utilized site-specific empirical relationships developed from detailed analyses on a representative number of proposed sedimentation ponds. Use of these equations provided earthwork volumes, and spillway pipe lengths. The procedure developed for this study is presented along with the results of a verification analysis.

Jan 1, 1983

By R. R. Klimpel

The process of flotation is an extremely important solids separation technique employed in a wide variety of industrial process applications. Froth flotation is practiced in the coal industry to recover fines produced during the mining and cleaning of coal. A recent review article by Aplan (1) covers the processing variables encountered in the flotation of coal and the variety of chemicals and operating conditions which affect recovery. Numerous engineering and scientific studies have been performed with the goal of providing semifundamental laws of flotation behavior for improved screening of flotation chemicals, better equipment scale-up factors, etc. Often the results of such work are expressed in the form of mathematical models (e.g. 2, 3, 4, 5, 6) which are potentially useful for evaluating (simulating) on paper such alternatives as possibles process operating or configuration changes, the effects of ore and reagent changes, etc. It appears to be commonly accepted that a complete scientific/engineering characterization of flotation is immensely complicated and not sufficiently developed at the present to accurately predict (or understand) many important industrial facets of flotation. Thus, one is often reduced to detailed experimental characterization in both the laboratory and plant in order to fully evaluate flotation changes or alternatives. It is the purpose of this paper to describe a method of batch laboratory data characterization that is useful in evaluating flotation chemical reagents including froth flotation of coal. The approach consists of running a series of time-recovery curves in a batch float cell followed by the computer curve fitting of this data to a series of mathematical models based on semi-physical reasoning. The unknowns or parameters of these models are then optimally chosen so as to best fit the experimental data. It has been found in both coal and mineral systems that changes in reagent type, concentration, system pH, grind, etc. cause very consistent and logical changes to

Jan 1, 1979

By Robert W. Bartlett

Both hydrometallurgical and vapometallurgical processes often involve ores that have been previously ground and size classified. When the valuable mineral is substantially liberated, the chemical reaction is likely to occur on the particle surface and the particle core will shrink as the reaction proceeds. If the chemical reaction products are solid materials then a solid shell, usually porous, will form around the shrinking core. This is known as the core/shell or topochemical reaction model. Using a spherical approximation for the particles, equations have been developed to express the extent of chemical conversion of the particle, depending on which one of the following process or mass transport steps is rate controlling:1 (1) chemical reaction at the particle surface, (2) diffusion through the thickening reaction product shell or (3) mass transport through a boundary layer surrounding the particle. In a previous paper2 these equations were coupled with the Gates -Gaudin-Schuhmann equation 3 4 describing the distribution of particle sizes resulting from comminution of rocks and other brittle solids to develop reaction yield curves expressing the weight fraction of metal or other valuable component of the feed that was chemically converted as a function of residence time. This was done for (a) batch, (b) continuous plug flow and (c) continuous back-mix flow (continuous stirred tank) reactors or process vessels. To make the curves of general rather than special utility, the residence time (average residence time for back-mix reactors) was normalized to a dimensionless time by dividing by the time required to completely chemically convert the largest particle in the feed to reac-

Jan 1, 1972

By F. G. Miller

It is generally accepted that sulfur exists in coal in three forms: (1) pyritic, (2) organic, and (3) sulfate sulfur. Sulfate sulfur usually makes up less than 1% of the total sulfur content. Pyritic and organic sulfur, make up almost all of the total sulfur and occur in varying amounts in different coals and can vary greatly in coal of the same seam Pyritic sulfurs of 20% to 80% of the total sulfur have been reported Other authors have shown that it is not possible to remove the organic sulfur without chemically altering the coal. Chapman and Jones (1) state: "Organic sulfur, unlike pyritic sulfur does not exist as discrete particles, but is intimately associated with the coal structure, and as such it is not possible to remove it or reduce its concentration by physical means." Any success in removing sulfur has come about by removing pyritic sulfur by physical means; therefore, removal of sulfur in the pyritic form is the subject of this investigation. The extent to which any impurities can be removed from a particular coal can be determined by a washability study. Outside of crushing coal, to finer sizes or chemically altering the coal, there are no known methods of changing this inherent washability characteristic. The efficiency of various methods used to remove impurities can be determined by comparison of results produced at a yield to the results as shown by a washability study. In recent years heavy media processes have proven their ability to wash plus 28 mesh coal and nearly produce results shown to be theoretically possible by the washability study. Therefore, it is the objective of this paper to show various methods of treating the finer fractions of the coal, in the hope of developing a process, which can effectively produce in the fine fractions the efficiency of heavy media devices in the coarse.

Jan 1, 1963

By John D. Hanifin, C. Kevin Moon, Eric C. Wang

Value Engineering on Connecticut DOT’s Walk Bridge selected the trenchless option for utility relocation to address the channel crossing’s environmental concerns. The design and construction considerations of the twin micro-tunnel drives and associated shafts are presented. Key challenges included vertical alignment selection to achieve minimum one-tunnel diameter stable cover within thin glacial till underlying extremely soft clay, limited choice of pipe and joint materials meeting stringent non-metallic conduit requirements, thermal grout backfill application, and the close proximity of temporary trestle piles. Mitigation measures were developed for potential point loading pipe damage from remnant boulder fragments in the annular space.

Dec 1, 2022

By W. C. Shanks

The Pioche District of Lincoln County in southeastern Nevada (Figures 1 and 2) has been an historically important producer of silver, zinc, and lead. Economic geology of districts in the Pioche area is summarized most adequately in recent reports by Tschanz and Pampeyan (1) and Gemmill (2) and only a few major aspects will be discussed here. Production in the Pioche District began in 1869 and early mining concentrated on silver-bearing fissures in lower Cambrian quartzites. In the early 1870's the Pioche District was second only to the Comstock Lode in world silver production (3). More recent mining activities have centered on the other major ore type in the area, bedded replacement of lower Cambrian carbonates by Ag-Zn-Pb sulfide ore. Production of replacement ore peaked around 1950. The present study is focused on the Pan American Mine because it is an excellent example of low grade carbonate replacement deposits, because there is little structural dismemberment, and because access was readily available. Most previous workers have suggested that both the fissure vein deposits and the bedded replacement deposits of the Pioche districts are a result of spatially related Laramide igneous activity. The purpose of this study is to determine whether ore genesis is a result of igneous activity or if mineralization might be related to late diagenetic processes such as formed Mississippi Valley "type" deposits. Stable isotopes of sulfur, carbon, and oxygen in ore and gangue minerals have been studied to determine the probable isotopic composition of the ore fluid and paleomagnetic studies of the carbonate rocks have been utilized to determine timing of mineralization. Additionally, petrographic and field studies of carbonate lithologies were undertaken in an attempt to delineate non-structural controls on ore localization. These studies are still proceeding and the results presented herein are, therefore, preliminary in nature.

Jan 1, 1979

By Tom Michaud, Rob Albinger, Ian Turner, Michael Rispin

Data transmission, communication, tracking, and the connection of equipment such as gas detectors, cameras, and collision avoidance systems in today's tunnel industry are critical pieces of the constructor's infrastructure. Reliability, flexibility, redundancy, and cost-effectiveness are key in selecting and implementing inte- grated systems. Both wired and wireless components are used to deliver custom solutions and can involve interconnectivity between backbones. Systems integration is important as industry adopts proven technologies from other industries. Case stud- ies are given showing how tailor-made approaches deliver needed functionality, with varying degrees of com- plexity, in various classifications of environment, in order to meet a project need.

Jun 23, 2024

By A. Haghighat

A risk analysis on mine fires for all U.S. underground coal mines from 2000–2012 was completed to identify locations that have a high risk for fire incidents. The data for this analysis was extracted from the Mine Safety and Health Administration’s (MSHA) mine fire accident reports database. After identifying fire incidents from this database, a risk matrix was developed for underground locations that showed a significant propensity for fire incidents. This matrix associates the hazards and risks with the severity and frequency of their consequences at each location. These significant mine areas will be the concentration of future studies in fire behavior, suppression techniques, and simulation methodologies. INTRODUCTION Fires in underground mines pose significant hazards to personnel because of inherent restrictions to movement and limitations to egress routes. Despite improvements, mine fires remain serious hazards in underground coal mine. In order to better mitigate the risks from fire hazards in the modern underground mining environment, a better understanding of where fire events occur must be gained. The following paper presents an investigation on the number of fatal and non-fatal incidents in underground coal mines fires from 2000 to 2012. Three phases of risk assessment (i.e., risk identification, estimation, and evaluation) were applied to the recorded fire events from the MSHA incident database that occurred during this time period. Using this process, a fire hazard was first defined. This definition was then used to identify any incidents that had occurred as a result of the defined hazards. The seriousness of the injuries and damages were finally quantified for each incident though an estimate of severity and frequency and then aggregated according to underground location (ISO, 1999; Van Duijne, 2008). Using this approach, locations prone to incidents resulting from fire hazards were first identified. The risk for the occurrence a fire incident in general was then estimated for each of the identified locations. The results of this assessment will be used to improve fire simulation techniques for the identified, high risk underground locations. RISK IDENTIFICATION A risk for this assessment was defined as any single occurrence of a fire initiated by the ignition of gas, dust, or electricity. Each recorded occurrence of such an event in the MSHA incident database was counted as a single fire incident. Both non-fatal incidents that were reportable but did not result in a fatality and fatal incidents that fell into the aforementioned criteria were counted. Incidents in the MSHA database that were already classified as “generic” were not considered. The remaining incidents were then totaled and aggregated according to the underground location in which they occurred. In previous studies, a number of locations, which are listed in Table 1, were highlighted as high fire hazard areas (McDonald et al, 1980; Pomroy et al, 1995; De Rosa, 2004). These locations were used to group the fire incidents extracted from the MSHA incident database. The compiled numbers of non-fatal and fatal underground coal fire incidents from 2000 to 2012 are displayed in Table 1.

Jan 1, 2019

By John M. Hird

Texas Gulf Sulphur Company's Lee Creek Mine has opened a major phosphate mining district in the Central Coastal Plains of North Carolina (Fig. 1). The ore deposit as it is now known was roughly outlined in 1961 by a Texas Gulf geologist using wire line exploration methods. Slightly uraniferous phosphate materials were detected by a slim-hole gamma ray probe run in numerous farmers' water wells penetrating the formations. A follow-up-core drilling pro- gram determined the economic ore limits to lie in the south central section of Beaufort County beneath 70 feet to 120 feet of unconsolidated sediments. The 50,000 acre deposit is known to contain over two billion tons of phosphate ore amenable to strip mining methods. A part of the deposit underlies several thousand acres of the Pamlico River estuary. The 90 million dollar capital investment plant built by Texas Gulf during 1965-66 included a strip mining operation using a 72-yard walking dragline, a three million product ton per year flotation concentrator, four fluid bed calciners, a sulphuric acid plant (acid for captive use), a phosphoric acid plant, and three solid fertilizer material plants. Shipment to domestic markets is by rail and truck and to over- seas markets by barge to a transshipment terminal at Morehead City, North Carolina. Early mining investigations were conclusive first that the phosphate ore could economically be recovered only by dry strip mining methods, and second that artesian ground waters in the formation (Castle Hayne limestone) underlying the ore would have to be controlled. This report will relate the application of ground water hydrology in depressurizing the Castle Hayne aquifer to facilitate dry strip mining at depths 130 feet below sea level at the Lee Creek Mine.

Jan 1, 1970

By James R. Strong

Before getting into the subject of packaging and materials management, please permit me to introduce you to MICRO SWITCH. MICRO SWITCH, A Division of Honeywell Inc. is located in Freeport, Illinois. We manufacture and market thousands of types of precision snap-action electrical switches. Most of them are used as components by other manufacturers in industrial and commercial products. MICRO SWITCH also offers a broad line of industrial control devices including heavy- duty limit switches, relays, manual controls and proximity switches. Other product lines are solid state keyboards for the computer industry and high-performance d.c. motors used in computer related equipment. So you can see that we are a component manufacturer. With the exception of the keyboards, every one of our products would "fit comfortably into a breadbox." Some are so tiny that one could easily fit several thousand into a man's hat. In my position as supervisor-packaging. package design, and materials handling engineering, I am actively involved in package design projects, parts handling design projects, and numerous activities involving departmental layouts, storage facilities, and material handling equipment. Two package design technicians, a materials handling engineer, and a materials handling technician make up the technical staff.

Jan 1, 1973

"Tell us how you got involved in mining and about your career path.My dad was a coal miner and my uncle was a metallurgist, so when I enrolled at Penn State’s New Kensington Campus, I chose the College of Earth and Mineral Sciences — exact majors didn’t get picked till the end of your sophomore year. Penn State New Ken had an associate degree in mining program and one of the guys in my carpool was going to take Mining 30 in the evening and the other guy (mechanical engineer) was also able to take an evening class. I didn’t want to break up the carpool, so I took Mining 30, complete with essay tests. I could write, so I did well, and the professor said I should go into mining engineering. Fast forward to the end of the next term at University Park, and I realized there wasn’t enough chemistry in mining. Switching to metallurgy would have meant another term at that point, so Dr. Lovell, my advisor, trotted me down the hall and to the next building and said I was a mineral processor. That stuck. I was a summer student at U.S. Steel Research between my junior and senior year and they paid for my master’s degree — all about clay and macerals in coal flotation. During that time, the steel industry tanked, and I thought a Ph.D. would be a good idea — I could always teach at the university level if I had those credentials. The Electric Power Research Institute had a Coal Cleaning Test Facility in Homer City, PA, and I conducted my Ph.D. research on rate and residence time in conventional coal froth flotation cells there and at a local cleaning plant. I went to work at the test facility in 1987 (later CQ Inc.) and stayed there until I started PrepTech Inc. in 1997. PrepTech offers some consulting services for coal cleaning plants and sells mineral processing equipment, mostly to coal companies. I can’t believe it’s been 21 years.And what about your SME career?Of course, I was a student SME member at Penn State. We used many of the SME books in class, so who wouldn’t want the student discount? While in Homer City, I became involved with the Appalachian Plateau Subsection of the Pittsburgh Section. We’d hold quarterly meetings with interesting speakers and had good attendance. I was the secretary. I’m still the secretary and also get the bank statements. We’ll need to close that out some time, but I guess I’ve been hoping for resurgence in the Indiana/Cambria/ Somerset area."

Jan 3, 2018

By T. Krichler

"Current mine control stations are either single-position systems with high engineering effort or all-in-a-box solutions with low integration possibilities of third-party devices. Above all, both approaches are cost-intensive and not feasible for small companies. This paper shall be an inspiration of how to enhance the productivity and monitoring of an existing mining system in a modular way by introducing a proven technique of the ongoing digital revolution: A Wi-Fi network based on the communication protocol OPC UA. The starter kit consists of a single-board computer, a WLAN access point and any electronic sensor. INTRODUCTION The majority of the European mining industry is run by small and medium deposits (Europe Geology, 2017). This is due to the fact that most ore mines in Europe are widely distributed within the continent, are generally small and additionally they are often steeply inclined. Such ore bodies are normally mined with underground mining methods and must be excavated with high selectivity because of their small thickness. That is why the economy of scales, higher efficiency through bigger machines, cannot be used in most deposits in Europe except for lignite mines. It is important to find an alternative possibility to improve the efficiency of European mines for making them competitive internationally. For cost optimization and profit maximization it is necessary to use the trends of industry 4.0 and to broadcast these into the mining industry to reach a technological advantage. The goals of the EU within the Horizon 2020 funded project are to shorten the actualisation of the mine and block model to hours, improve the communication with Through the Earth (TTE) via very- or ultra-low frequency for long-time monitoring of the abandoned workings, and develop a cost-effective mine control station for optimization of mining processes in Small and Medium Enterprises (SMEs) as well. This paper deals specifically with the new approach for data acquisition, transmission and visualisation of a mine. SCADA AND ERP IN MINING There are already many Supervisory Control and Data Acquisition (SCADA) and Enterprise Resource Planning (ERP) programs on the market, but these are normally not developed for the mining industry. At the moment this leads to three options. • To hire a system integrator, who shall build a complete control station for one mine that requires a high amount of knowledge in programming and cannot be maintained by the mining company itself. • To buy different types of out-of-the-box systems, whereby every system can include some of the used technology. In this case a huge amount of project engineers and operators – at least one per system and shift- is required. • To buy every machine and program from one company including the service contracts."

Jan 1, 2018

By J. C. Draper

This subject was introduced last April in a paper presented in Birmingham, Alabama, by James E. Elkin, General Superintendent of Duquesne's Coal Department. This paper will cover some of the same data and in addition it will update and further describe our experience. Our Portal No. 3 was started in June 1965 with battery tractor-trailer face haulage. This mine is operating in the Sewickley seam in Dunkard Township, Greene County, in Southwestern Pennsylvania as shown on Fig. 1. The Warwick group of mines fronts on the Monongahela River and extends westward for some ten miles as shown on Fig. 2.

Jan 1, 1968

By D. W. McGlashan

Zeta potential changes were determined as a function of pH, metal ion, and surfactant concentrations. Prom the analysis of data, flotation experiments were carried out to correlate float-ability with the differences in zeta potential. Cassiterite in water bears a negative zeta potential, The zeta potential of cassiterite is sensitive to pH changes; the electric double layer arises from the preferential adsorption of H+ and OH- ions and subsequent ionization of the hydroxylated surface. It is suspected that hydronium-ion concentration may cause reversal in the sign of the zeta potential. The ZPC was found to occur at pH 3.4. Metallic ions and the hydrated ions thereof affect the zeta potential of cassiterite in differing degrees of intensity. Without prior activation, sulfonated surfactants do not change the zeta potential of cassiterite. Sodium alkyl aryl sulfonate is especially active on lead-activated cassiterite and ferric-activated cassiteriten Microcalorimetric fiests confimed the activity of ions on cassiterite and showed the hydrated character of cassiterite smfaces. Close correlation between zeta potential and microflotation results was achieved.

Jan 1, 1969

By PDF

Flotation columns are widely used in mineral processing and coal preparation industry today. Mathematical modeling of flotation columns has conventionally been done using axial dispersion or tank-in-series models. However, for design and scale up purposes these models are not adequate enough because they do not provide detailed information of the flow fields within the column. This paper presents a Two-Dimensional, Two-Phase. Fluid-dynamic Model and its numerical solutions for some cases encountered in column flotation. The MAC (Marker and Cell) method was employed to obtain the numerical solutions, and based on this method a computer code COLUMNFLOW was developed. The simulated flow field reveals the presence of a circulation flow structure in flotation columns, which could be one of the main reasons for mixing in column flotation. The effects of some parameters such as superficial gas and liquid velocities on the characteristics of the flow structure in flotation columns were also tested with the numerical model.

Jan 1, 1994

By Max Friedemann, Alexandros Bousdekis, Anna Gustafson, Helmut Mischo, Håkan Schunnesson

Many devices used in mining are not monitored by sensors or do not have their own intelligence. By retrofitting sensors and real-time data processing, machines can be integrated into an existing digital infrastructure. Within the project Mine.io funded by the European Union a Sandvik DE110 exploration drill rig is being digitized using various AI algorithms at research and education Mine “Forschungs- und Lehrbergwerk Reiche Zeche (FLB)” of TU Freiberg. The aim is to increase the productivity of drilling with real-time evaluation of the current rock to be drilled and the current maintenance status of the drill rig. The drill rig is equipped with a speed sensor, pressure sensors in the hydraulics, 3-axis vibration sensor, borehole length measurement and temperature sensor. The sensors are additionally attached to the drilling rig and no structural changes on the drill rig are necessary. All data are processed real-time at a server structure outside of the mine using AI algorithms to analyze which rock (ore or host rock) is being drilled and to perform predictive maintenance. Processed Data are visualized for the operator to optimize the workflow and the productivity.

Feb 1, 2025

By Ehsan Moosavi, Kamyar Tolouei, Mehran Gholinejad

The literature defines rockbursts in slightly different ways based on their generation mechanisms, field phenomena, and degree of damage, but in a way that is almost consistent. Generally, a rockburst refers to seismic events that mainly happen in underground excavations, for purposes such as underground mining, road and railway tunnels, nuclear power, etc., and that are followed by the collapse and outburst of rocks. Long-term rockburst prediction can be abstracted as a classification problem mathematically, in which we can introduce deep learning to solve it. Further, using deep learning in rockburst prediction can overcome drawbacks such as subjectivity and inconsistency brought from previous traditional approaches. A rockburst data-set, was employed to evaluate the current method for predicting rockburst grade, and the good results of overall success rate were obtained. The results indicated that the proposed algorithms can speed up parameter optimization search, the proposed method is robust model and might hold a high potential to become a useful tool in rockburst prediction research.

Apr 26, 2022

By Nathaniel White, Todd Kilduff, Justin Laviolette, Dan Laviolette, Randy Zeigler, Sean Sundermann

The Mitchell Point tunnel is a part of several ongoing efforts to connect the 12-mile-long Historic Columbia River trail between Mitchell Point Outlook to Mitchell Point Drive. The tunnel lies inside the Mitchell Spur entablature basalt geologic feature, extending 647 linear feet utilizing a typical horseshoe section with a height of 14.5 feet. The Oregon Department of Transportation (ODOT) required proper vibration control to minimize potential impacts to Interstate 84 and Union Pacific rail immediately below the tunnel excavations and sensitive, rare plants. The method of designing the vibration monitoring program and the results of its implementation show the iterative process of using monitoring to improve blast design as excavation proceeds, such as reducing air overpressure and COVID-related supply chain-constraints.

Dec 1, 2022

By Ronald M. Hays

During the twentieth century the Mesabi Range in northeastern Minnesota has been the major source of iron ore for American steel mills. The Mesabi Range extends along an iron bearing outcrop known as the Biwabik formation. This outcrop is some 120 miles long and up to three miles wide. The formation is from 200 to 650 feet thick and dips 5 to 10 degrees to the southeast. The iron content of the original Biwabik formation was quite uniform, but much of this formation has been subjected to alteration. Thus major variations in iron content and mineral composition exist both laterally and vertically in the present Biwabik formation. The remaining unaltered iron formation includes the magnetic taconites which are commercially processed by Reserve Mining, Erie Mining, Eveleth Taconite, National Steel, Butler Taconite, and U.S. Steel. These six operations have a capacity of 32 million tons. per year of iron pellets and have produced approximately 170 million tons of pellets since 1956. Capacity for another 30 million tons per year of pellets is being considered by the industry for the next ten years. This increase will be obtained by construction of new plants and expansion of present operations. Thus by 1977, it is estimated that approximately 60 million tons per year of iron pellets will be produced from magnetic taconite on the Mesabi Range. The portions of the Biwabik formation subjected to intense alteration resulted in the direct shipping, wash and heavy media ores. Since 1892, 1.8 billion tons of direct shipping ore have been shipped from the Mesabi Range. This ore has been the major source of iron for American steel mills. In 1966, 12 million tons of direct shipping ore and 18 million tons of wash, jig, heavy media and other gravity concentrates were shipped from the Mesabi Range. These products generally have poorer physical and chemical properties than the iron pellets produced from magnetic taconite. It is predicted that the shipment of these materials will decrease from about 30 million tons in 1966 to 6 to 8 million tons in 1975. This decrease will be due to depletion of reserves and poor quality product.

Jan 1, 1968

By K. A. Natarajan

The utility of yeast, Saccharomyces cerevisiae, in the separation of quartz from hematite is demonstrated. Yeast cells, as well as their metabolites, functioned as flotation collectors, depressants or flocculants and dispersants for hematite and quartz. Interaction between yeast and the above minerals resulted in significant surface chemical changes, rendering quartz surfaces hydrophobic and hematite hydrophilic. Mineral-specific extracellular proteins and exopolysaccharides were secreted by yeast cells when grown in the presence of quartz and hematite, respectively. Quartz could be efficiently separated from hematite through microbially induced flotation and selective flocculation.

May 1, 2012