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By George M. McArthur

General Statement In Montana, as in most states, the requirements for water quality control are becoming more restrictive. What was once accepted practice is now obsolete. The planning and construction of water quality control facilities has taken on new importance. Past practices and new ideas must be examined to meet the challenge. By this paper we hope to encourage the exchange of ideas for the improvement of water quality control techniques. Both the mining industry and governmental agencies should benefit from such an exchange. The following is a summary of the work done and in progress by The Anaconda Company in Butte to provide an improved water quality related to production processes. We invite your comments. Acknowledgements This paper would not have been possible without the efforts of many individuals and departments in The Anaconda Company, including the Environmental Engineering Department, Mr. Frank J. Laird, Director; Montana Operations, Mr. M. K. Hannifan, General Manager, and their assistants.

Jan 1, 1972

By C. Haycocks

The Appalachian coal fields contain many mineable contiguously placed coal seams. Selection of the mining sequence for these seams, historically and currently, is based primarily on considerations of seam ownership, availability and economics. Mining any seam can seriously affect subsequent operations in coal seams both above and below the one being mined. The effect is often detrimental to recovery costs and safety of mining in the subsequent seams. The purpose of this paper is to examine the conditions that can develop in an underlying seam due to stress concentrations that can occur below pillars or abutment zones in an overlying seam, and suggest guidelines for avoiding them. This situation most commonly occurs when the overlying seam is mined first, although simultaneous and subsequent mining of the upper seam can also produce such effects. Other interaction phenomena resulting from subsidence or arching will not be considered here. The methodology used in this research utilized both computer and body loaded photoelastic models to study the interaction mechanisms. Field studies are used in both interpretation and analysis of the results. Numerous examples of load transfer from upper workings exist in all parts of the world and many of these have been incorporated into this work. Such interaction problems are quite common and likely to be an ever increasing occurrence as mining activities in old seams are completed and new seams opened up.

Jan 1, 1982

By K. K. Bhattacharyya

In the Gulf Coast area lignite deposits occur in Texas, Louisiana, Arkansas, Mississippi and Alabama. Lignite has been mined in Texas since the early 1800's reaching a production of over 900,000 metric tons (1 million short tons) in 1910. With the availability of inexpensive oil and gas, production fall to as low as 16,000 metric tons (18,000 short tons) by 1950 (Henry, 1976). With the advent of the oil and gas shortage in early 1970, lignite production began to increase again. The purpose of this paper is to discuss the geotechnical considerations of mining lignite in the Gulf Coast area, particularly Texas and Louisiana. Lignite deposition occurs in unconsolidated sand, silt and clay environments. Extensive sand units saturated with water may be present within the potential mining depths. This paper describes the geotechnical considerations for designing a surface mine in this geographical area. These factors include geology, hydrology, mining method, and equipment utilization.

Jan 1, 1982

By T. F. Torries

Market data commonly perceived as being useful to industry for decision making include prices, production and trade quantities, production and transportation costs, stocks, customer's needs, and competitor's qualifications. Costs and factors affecting costs are particularly important in determining competitive positions and possible future prices. These costs include relative cost of production as well as cost experienced by the buyer in making the final product. Care must be taken to calculate costs in a consistent manner to achieve meaningful analyses.

Jan 1, 1987

16.1.1-VENTILATION'S ROLE Importance of Ventilation and Environmental Control-Mine ventilation is necessary for the preservation of human life and for the conduct of operations involved in the underground extraction of minerals. It clearly is the most essential of the functions attendant to mining, yet it is auxiliary to the primary objective in mineral extraction. Ventilation in mining thus poses a paradox: ideally, it should be carried out with minimum interference with and cost to production operations, yet it is absolutely vital in providing adequate environmental con¬ditions to support mining. Deterioration of the atmosphere, along with rising ground pressure, imposes the ultimate constraint with depth in underground mining. Ventilation requirements and costs rise rapidly with depth. To preserve atmospheric quality under intense heat conditions, ventilation at great depths must be supplemented by air condition¬ing. Likewise, when mining at any depth under severe or excessive conditions of gas, dust or humidity, supplementary control measures must be employed. In recent years, environmental standards in mines have been raised substantially. While limits are based on human tolerance, increasing concern is being expressed for standards of human comfort. The reasons are economic, as well as humanitarian. Worker performance and longevity correlates closely with environmental quality. Further, adverse accident and insurance compensation rates are a consequence of unsatisfactory environmental conditions. No mining company can afford to be lax in its environmental and ventilation practices. Functions and Processes-Ventilation is the control of air movement, its amount and its direction. As a means of quantity control, it is one of the constituent processes of total air conditioning, the simultaneous control within prescribed limits of the quality, quantity and temperature-humidity of the air. Ventilation is the most common and most. important conditioning process employed in mines for air environmental control. In mine ventilation, air is coursed through the mine workings and openings themselves and, for auxiliary purposes, through vent tubing and ducts. Thus, many interdependencies exist between the mining system and ventilation method. In fact, the two often have evolved ,jointly, as in room-and-pillar extraction of bedded or tabular mineral deposits, such as coal. Ventilation in mines today is provided almost exclusively by large fans, although air flow may result due to natural (thermodynamic) conditions. As mines increase in depth, size and complexity, demands on the ventilation system to maintain more stringent standards of environmental quality likewise rise. On the other hand, never have the technology and resources of the mining industry to cope with environmental problems been so well developed as they are today. In spite of rising costs, it is unlikely that further progress in mine ventila¬tion and air conditioning must await technological breakthroughs. 16.1.2-NATURE OF THE MINE ATMOSPHERE Air Mixtures-Air is a gaseous mixture comprising the natural atmosphere at the surface of the earth. Thermodynamically, it may be thought of as a mech-

Jan 1, 1973

By J. L. Mehaffey

A variety of chemicals offered by Armak were evaluated as dewatering aids for aqueous slurries of silica sand, sparsand and feldspar; an established commercial dewatering aid was used as a control. A number of Armak's potential dewatering aids yielded lower moisture retention values than did the commercial product on all of the mineral samples. In addition to the chemical dewatering evaluations, some of the mechanisms involved in the removal of water from these mineral samples were examined.

Jan 1, 1983

By P. T. Bissert, J. P. Ducarme, J. L. Carr, A. K. Smith

The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities, or 82 percent, may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible.

Jan 1, 2016

By Hesam Dehghani, Farid Alimohammadnia, Nima Babanouri, Mokhtar Kalhori

In open-pit mining, blasting pattern design is performed to achieve a desired degree of fragmentation for loading, hauling, and crushing operations. Inappropriate fragmentation of rock will result in numerous problems such as incurring extra costs for secondary blasting, production interruption, etc. Wetness of the blast holes is one of the most important factors, which can cause the inappropriate rock fragmentation. Lowering ambient temperature in the vicinity of the explosion, the presence of water in the hole adversely affects the quality of the explosive while dissipating part of the explosion energy, ending up with inappropriate fragmentation problems. In the present research, in order to study blast-induced fragmentation conditions in Baba-Ali Iron Ore Mine, three scenarios were considered: explosion of ammonium nitrate with fuel oil (ANFO) in dry hole, explosion of ANFO in wet hole, and explosion of the emulsion in wet hole. For this purpose LS-DYNA, a numerical simulation code was used. Results of the present research showed that, compared to the explosion of ANFO in wet hole, the explosion of the emulsion produced more uniform distribution of fragment size, while the explosion of ANFO in dry hole resulted in fewer large fragments.

Ventilation 'is currently used in mines to sustain human life, prevent explosions, and provide a more healthful work place. Future automated-mining systems could use ventilation techniques quite. different from today's practices. The Bureau of Mines is anticipating various methodologies for ventilating the automated mining systems which are now beginning to emerge in the mining industry. This paper examines the special ventilation requirements for automated mining systems. Topics include requirements for automated systems, current studies with blowup ventilation tubing, and ventilation of two types of highwall -ripper type mining machines.

Jan 1, 1990

By P. T. Bissert, J. P. Ducarme, J. L. Carr, A. K. Smith

"The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities (82%) may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible. INTRODUCTION Underground coal miners are exposed to a variety of hazards on a daily basis. Among coal and rock dust exposure, high noise levels, roof and rib falls, and the potential for fires and explosions, operating and working with heavy machinery poses a significant risk to miner safety. One of the most hazardous jobs is operating or working nearby a continuous mining machine (CMM). According to Mine Safety and Health Administration (MSHA) statistics, 39 miners have been fatally struck or pinned by a CMM since 1984. In an effort to prevent future striking and pinning fatalities from occurring, proximity detection systems have been developed and are now required on all operating CMMs in underground coal mines with the exception of full-face CMMs [1]. Commercially available proximity detection (cPD) systems are based on the principle of magnetic flux density (B-field). Typically, four magnetic field generators are positioned on a CMM, and personal alarm devices (PADs) are worn by the miners that detect magnetic flux density difference. As a miner wearing a PAD gets closer to the machine, the flux density increases. Zones can be constructed around the machine so that an alarm will trigger on the PAD based on the flux density."

Jan 1, 2016

By Janet Briggs, Michael Vertes, J. F. Shirley, R. E. Cutherbertson, Alexander Sutulov, J. D. Vincent

Molybdenum, the 42nd element in the periodic table, is now a very important metal in industry of the United States and the world. Chemically, it is a very complex element having valences of 0, +2, +3, +4, +5, and +6, and can exist as a mixture of these valences in many compounds. It was discovered and separated by Scheele in 1778. At the present time, molybdenite is the only important commercial source of molybdenum. Molybdenum occurs in some 12-14 different recognized minerals, but practically all of the production is molybde¬nite. As late as 1915, it was considered a rare metal. Germany made extensive use of it during the first world war, which resulted in the establishment of a molybdenum industry in the United States at Cli¬max, Colo., in 1917. It was not until the mid-1920s when its introduc¬tion to steelmaking developed for the US automobile industry that the metal gained important acceptance. The first notable example was the Willis-Saint Claire automobile introduced in 1921 by C. Harold Willis, formerly chief metallurgist for Ford Motor Co. Molybdenum has also been produced in the US from wulfenite (PbMoO4) from Arizona and Nevada, and a small amount of molyb¬denite was produced up to the early 1970s as a coproduct from two molybdenum-bismuth mines in Quebec, Canada. The first byproduct production of molybdenite from a copper con¬centrating operation was achieved at Cananea, Sonora, Mexico, and was followed shortly by the Utah division of Kennecott Copper Co. in the mid-1930s. This section of the Handbook is divided into four main subdivi¬sions: Chapter 2, which deals with the concentration and recovery of molybdenite from primary molybdenum ores; Chapter 3, which deals with the recovery and separation of molybdenite as a byproduct from copper production; Chapter 4, which deals with the conversion practices employed for converting molybdenite to the oxide or metal form; and Chapter 5, which covers the uses of molybdenum in steel¬making, chemicals, pigments, lubrication, catalysts, etc. The Free World molybdenum production, for the past eight years from all sources, is shown in Table 1. 2. Primary Molybdenite Ores General In 1978 there were four primary molybdenite recovery plants in operation: Climax, Endako, Quests, and Henderson. For over half a century the Climax mine has been by far the largest and most important source of molybdenum in the world. During the early 1970s a few primary molybdenite mines in British Columbia were shut down due to adverse economical conditions. The largest of these was British Columbia Molybdenum, formerly owned by Kennecott Copper Corp. The Climax plant and operations are described in detail and the opera¬tions of the other plants are summarized following a general discussion of recovering molybdenite from primarily molybdenite ores. Recovery of molybdenite as a byproduct will be taken up in Chapter 3. Geology Molybdenite production from mines in which it is the sole or preponderantly important mineral is confined to ore bodies in granites or igneous-type rocks or pegmatite dikes. More than one state of mineralization is sometimes present as at Climax, York, Hardy, and Questa. In the case of Climax, important byproduct recovery of tung¬sten, tin, pyrite, and monazite is also attained. The molybdenite is commonly disseminated very finely in the siliceous granitic gangue but does occur in stringers and blebs in silicified mineral solution channels. Treatment of Primary Molybdenum Ores All primary molybdenum ores are low in molybdenite, the content ranging from less than 0.20% MoS2 to a high of about 0.40% MoS2. A high resistance to grinding is a common ore characteristic combined with a habit of very fine dissemination of molybdenite in the siliceous portion of the ore. Because of low MoS2 content, high hardness, and fine dissemination of molybdenite in primary ores, it has been necessary to develop a special mill treatment which yields an accepta¬ble recovery at a reasonably low milling cost. Essentially, the treatment consists of intensive rougher flotation at a relatively coarse grind with production of a low grade rougher froth containing a substantial percentage of the molybdenite in the form of low grade middling particles, followed with multistage regrinding to liberate the locked molybdenite and several stages of flotation cleaning to produce a finished grade concentrate. Rougher flotation on pulp ground to ap¬proximately 35 mesh is common practice, even if complete liberation of molybdenite from siliceous gangue may require regrinding to 200 mesh. The flotation of middling particles with a very low content of molybdenite in the rougher flotation step has been made possible by the application of a combination of reagents first developed at the Climax mill and used with some modification in the treatment of all primary molybdenum ores. The reagents commonly employed and their functions in flotation are:

Jan 1, 1985

This chapter contains the edited transcript of the "Gold Heap Leach Information Exchange" session that was held at the 1990 SME/AIME Annual Meeting in Salt Lake City, Utah. The exchange occurred on the afternoon of February 27, 1990. The session was intended to act as a forum for discussing some of the more prominent operating problems associated with heap leaching precious metals. The information exchange was very successful. The exchange consisted of several panelists introducing and discussing different topics, follow by a comment and question period. This transcript contains the panelists' presentations as well as comments and questions from the floor and the panel. Extraneous comments and remarks have been edited out. Some wording has been changed for clarity, but the transcript is basically an accurate account of what was said. At the end of the transcript are two papers submitted as part of the panel discussion

Jan 1, 1990

By M. C. Williams

As the flaws in the population balance model (PBM) comminution model are examined more deeply, further errors and problems were discovered. The Levenberg-Marquardt algorithm for systems of constrained non-linear equations was used to solve the dynamic PBM grinding equations to obtain the grinding selection and breakage rate functions. The fact that the PBM model equation Inverse Problem is degenerate or underspecified is demonstrated. Multiple solutions to the same PBM equations are provided. It is shown that there is no unique solution to the Inverse Problem unless additional constraints are provided or assumptions are made such as the Arbiter-Bhrany normalization assumption. The severity of the non-uniqueness problem for dynamic grinding is demonstrated. Each solution to a dynamic PBM, while giving the same prediction for a given grinding time interval, gives different solutions or predictions for mill composition for other grinding times. Actual experimental grinding data was assessed to determine the functionality of mill selection and breakage functions.

Jan 1, 1993

By J. D. Miller

Flotation chemists have long sought to unravel the mechanisms of carboxylate collector adsorption by semi-soluble salt minerals. In particular, the adsorption density of adsorbed carboxylates, adsorption kinetics, speciation (chemisorbed, physisorbed), orientation, and conformation are of interest. Given the importance of these phenomena in establishing the hydrophobic state at a mineral surface, in-situ surface spectroscopy studies certainly are justified. Such measurements traditionally have been difficult to perform. However, beginning in the late 1980s, a Fourier transform infrared (FTIR) spectroscopic technique was developed that has allowed for the acquisition of a wealth of detailed information concerning carboxyiate adsorption in semi-soluble salt flotation systems. The technique, internal rejection spectroscopy using single-crystal internal reflection elements, is reviewed, as it applies to semi-soluble salt flotation systems.

Jan 1, 1999

By D. Kang, K. N. Han

The adsorption behavior of silver in ammoniacal solutions on activated carbon was studied. In addition to the concentration of ammonia, the parameters that affect adsorption include temperature, degree of agitation and anion and cation concentrations. In the study, it was found that the adsorption of silver from ammoniacal solutions is dependent on the initial silver concentration in the solution. It was also found that the recovery of silver from ammoniacal solutions is not as effective us gold. The adsorption rate was relatively slow overall, despite a rapid initial adsorption. The apparent activation energy ,for the adsorption was measured at 30.2 kJ/mol. It was believed that the kinetics of the silver adsorption on activated carbon was limited by a mixed control mechanism.

Jan 1, 1999

By John E. Miller

In recent years there has been increasing concern in the mining industry over the availability and high cost of diesel fuel to support mining operations. Unit Rig & Equipment Co. has been deeply involved with the development and testing of the newest designs for trolley assist. Beginning in dune 1980, Unit Rig modified and commissioned six 156 metric ton (170 short ton) trolley assist haulage trucks at two mine locations in South Africa. Operating haulage trucks with General Electric GTA 15E/776 drive systems were chosen for the tests since this size of truck represented the majority of the population of large size haulage trucks and the greatest technical development problems. Test operations have proven the feasibility of equipment designs in actual operation and preliminary economic data has convinced the operators to proceed with planning to modify their entire mining operation to use trolley assist. The initial capital investment incurred for trolley assist can be recovered in a short period of time. Following this quick capital recovery, mines will continue to realize lower operating costs through increased productivity and lower diesel consumption.

Jan 1, 1980

By Randal J. Barnes, Franck Rellier

Mine ventilation survey data includes generally redundant, usually inconsistent, often incomplete, and always noisy measurements. Yet, these data are essential for operational decisions and represent the foundation of any mine ventilation systems model used for future engineering analysis and design. For example, the basic ventilation network geometry can be measured with a reasonable precision, the network flows can be measured, but with significant errors, and the branch resistance factors can not be directly measured at all. The network-based, constrained weighted least squares approach, presented in this paper, advances a method for the sys tem-wide adjustment of ventilation branch measurements and the consistent estimation of global system parameters (e.g. branch flows, head losses, and resistance factors). The constraints guarantee that the adjusted values satisfy the governing physical laws: conservation of flow, conservation of energy, and the appropriate energy dissipation rule (e. g. Atkinson's RQ2). The weights allow for the proper inclusion of data with widely disparate precision, as well as offering a simple method for retiring old data as the mine changes through time. The post-adjustment sensitivity analysis presents two potentially useful forms of analysis: the identification of previously unspecified leakage branches, and the semi- automatic recommendation for future ventilation measurement campaigns. The overall efficiency of the algorithm is exemplified by the fact that a ventilation network with hundreds of branches and thousands of measurements can be routinely adjusted on a microcomputer.

Jan 1, 1989

By I. Papadopoulos

Nowadays, geophysical prospecting is implemented in order to resolve a diversity of geological, hydrogeological and geotechnical problems. Though plenty of applications and a lot of research have been conducted in the country-side, only a few have been reported in the literature concerning urban areas, mainly due to high levels of noise present that aggravate most of the geophysical methods (e.g. electromagnetic, seismic, gravity etc.) or due to spatial limitations that hinder normal method implementation (e.g. electrical). Among all geophysical methods, electrical tomography proves to be the most rapid and urban noise insusceptible technique. This work presents a case study in the urban area of Hania (Crete I., Greece), where Electrical Resistivity Tomographies (ERTs) have been carried out for the detection and identification of possible buried ancient ruins or other manmade structures, prior the foundation of a building. Nineteen profiles were surveyed in a 20x40m grid using dipole-dipole configuration. The results indicate two areas of interest, that are interpreted as probable old wells, in the context of the existence, in former times and in the same area, of an olive oil plant. In the vicinity, near surface ancient ruins have been disclosed, but no such evidence provided this survey, for the particular area under study and the prospected depth. The collected ERT-data were processed by applying advanced algorithms in order to obtain a 3D-model of the study area that depicts more clearly and accurately the interesting subsurface structures.

Jan 1, 2005

By Joe Keane

DOUG HALBE: The kickoff speaker, and my unanimous choice, is Joe Keane. Joe was born in Butte, Montana, and began his association with the mining industry as an under- ground miner at age 16. Currently he is president of KD Engineering and Metcon Research. He had it lucky when he went to school because there were only 44 elements in the periodic table, I understand. [laughter] Here's Joe. JOE KEANE: I'm doing this under protest. Maybe we can start the slides. Mr. Halbe gave me this topic, but I don't like it. I don't like Mr. Halbe either [laughter] because of the way he shanghaied me into this. He called me up on the phone and said this is what you're going to speak about: "Five Things I Never Want to See Again in Plant Design," and I said, "Huh!" Then I started getting stuff from SME about how to make a presentation. I have decided to change the title to "More Than Five Things I Never Want to See in Plant Design," since you can't have a completely negative speech; you have to have other topics. So we will have some other, not completely nonrelated, topics to sort of break the tension. I tried to find a joke to open with. I talked to Omar Mutati. All of his jokes were either about Bill Clinton, our beloved President, or they were too filthy to say in a mixed group. [laughter] So I decided to start this out with a profound statement. The pro- found statement is, "The meek shall inherit the earth, but not the mineral rights," [laughter] by J. Paul Getty. J. Paul Getty was one of my favorite guys because when a real obnoxious reporter asked him one day, "How can I become wealthy?" he said, "Drill for oil and find it."

Jan 1, 1998

By J. Herbst, C. C. Harris, G. Poling

The modern flotation machine is the result of decades of adaptation to a changing environment. In response to falling ore grades, and rising demands, tonnages, and costs, attempts are now underway to expand machine capacity by about an order of magnitude, while at the same time maintaining metallurgical performance and if possible reducing power requirements per unit throughput. Empiricism and rule-of-thumb have guided flotation machine design and scale-up, and a current need is for the development of a fundamental understanding of the subject. Design features of current and some obsolete machines are discussed in an attempt to outline those principles of flotation machine design which are known, and to delineate topics needing investigation. Attempts are made to distinguish between essential machine features required by the physics of the process, those features resulting from speculative theories on the flotation mechanisms, and features which are essentially styling variations. Topics discussed include: flotation mechanisms; tank and impeller/ stator design and dimensions; impeller speed; aeration; power consumption; particle suspension and dispersion; capacity; correlation of design parameters and operating variables; scale-up and scale- down; materials flow; problems in machine design. Design details and operating data for several current machine families are provided in Appendices.

Jan 1, 1976