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By Brenda J. Wolfe

Following successful laboratory and pilot plant investigation of dewatering characteristics of molybdenum concentrate produced by a Chilean copper/moly producer, two (2) DENVER SALA 500 Series Tube Press Filters were installed in 1994 to handle the total production volume. Moisture requirements in the filter cake have been consistently met, eliminating the need for thermal drying after filtration. Operating data and Tube Press Filter are described herein.

Jan 1, 1995

By C. B. Manula

Languages such as SIMSCRIPT and GASP have reduced the programming skills required to build simulation models, but not to a level where these can be used by a busy engineer or manager unless he has extensive programming experience. In an attempt to make simulation a more readily available tool, Sanford (1969) structured a generalized materials handling model (UGMHS)* for underground coal mining. The majority of materials handling systems consist of a set of moves and a set of pieces of equipment required to execute the moves. UGMHS gives a technique for describing and classifying the elements in these sets and then a technique for simulating the interactions of these elements as the materials handling system operates. To apply the model, the user simply furnishes data parameters and a fixed set of orders to the computer for his own problem. This new philosophy of dynamic simulation as applied by UGMHS was demonstrated in the paper by Sanford and Manula (1973). A dynamic model of underground coal mining was presented for the purposes of systems design and selection of equipment for a completely new operation and the analysis of existing ones for possible alterations, additions, and general improvements. The main differences between this application and its predecessors is the ability to transport material from multiple mine faces to multiple mine destinations and the ready adaptability to a wide variety of mine layouts. The second difference that characterizes the model is the deterministic simulation of equipment moves according to their mechanical capabilities and the physical profile of the mining scheme. Here, the computer generates performance data in the absence of time studies to compare equipment rather than operator performance.

Jan 1, 1974

By G. Pan

A geostatistical approach is proposed for the design of infill drilling programs. The method consists of the following four major steps: developing geological favorability models, delineating mineralization and ore envelopes, classifying resource potentials, and designing infill drilling patterns. Geological modeling develops the permissible geological zones in which infill drilling is designed. Modeling mineralization and ore envelopes establishes criteria on the potential blocks to be drilled. The blocks that are included within the ore envelopes are considered in the infill drilling. The following four types of resource potentials are used in this analysis: measured, indicated, possible and barren. Blocks in the indicated category are the top targets to be confirmed in infill drilling. Blocks of possible resources may be considered exploration targets. The algorithms involved in the analysis include indicator favorability analysis, indicator kriging and ordinary kriging. A case study on a gold deposit of the Carlin type is presented to demonstrate the methodology. The deposit was originally delineated by a sparse drilling program with about 230ft of average spacing. The infill drilling design, based on the new method, suggests a significant reduction on the number of holes from a regular-grid infill drilling pattern.

Jan 1, 1996

By Harrison H. Roberts

A. We are aware that many who are in the audience have perhaps heard before some of the material which will be presented. Since our firm is more closely associated with the heavy construction industry our experience is more oriented in that direction. Notwithstanding this, the subject your program committee has asked us to present centers mainly in the earth-moving field. We find a common denominator between say, the stripping of a site to uncover an ore-body which will be developed by open-pit methods, and that of excavating & transporting materials for an embankment dam, airport or other project. Both are earth-moving problems and we offer for your consideration a means of determining the most favorable method, equipment selection and resultant cost. We do considerable studies involving rock excavation for tunnels, underground powerhouses, inclined and vertical shafts for penstocks, muck-removal, electrical cable & other related underground work. Hence, we believe we speak the same language.

Jan 1, 1972

By Francesco Chiappalone, Daniele Nebbia, Lance Waddell, Greg Colzani

As part of the 3RPORT Project, a 5-mile tunnel is being excavated underneath the three rivers of Fort Wayne using a 19-foot diameter Slurry Tunnel Boring Machine. The groundwater pressure at the tunnel axis ranges from 4.5 to 5.3 bar. The rock mass hydraulic conductivity is very high with water inflows up to 10,000gpm imposing significant challenges to the project. After excavating 1,550-feet of the TBM tunnel, major leaks between the tailskin and the segmental lining were observed, indicating the potential deterioration of the tailskin brushes and the need for inspection and eventual replacement. The first part of the paper describes the planning of the intervention, including the design of the polyurethane grouting campaign, the procedures developed for the execution and the controls established during construction to timely assess the presence of potential hazards. The second part of the paper focuses on the experience gained during execution and lesson learned to prevent future occurrences of this nature.

Jun 13, 2021

By Douglas F. Crickmer

Pocahontas Land Corporation, a wholly-owned subsidiary of Norfolk and western Railway Company, owns a 100,000-acre block of coal lands in Martin, Johnson, Pike, Floyd and Lawrence Counties, Kentucky. These holdings were largely acquired in three major purchases between the years 1942 and 1959. The area is undeveloped and constitutes a part of the coal reserve for future mining. This block, which is principally in Martin County, lies in a triangle formed by the Levisa and Tug Forks of Big Sandy River on the sides with Dewey Dam at its base and the Town of Louisa at the apex. The topography'is typical of eastern Kentucky and consists of steep hills rising from 500 to 800 feet above creek level. There is little level ground in the area. As a matter of fact, some roads are on the creek bottoms with what little bottom land is available in the hollows being utilized for small-scale farming. The steep hills are marked by three separate massive sandstone formations which form cliffs ranging from 40 to 100 feet in height.

Jan 1, 1964

By George R. Huebner

The White Pine Copper Company, subsidiary of Copper Range Company, is located in the Upper Peninsula of Michigan. The offices, plant, and mine are six miles south of Lake Superior in Ontonagon County. Employing 1700 people, White Pine is the largest single industry in the Upper Peninsula. 970 underground employees produce 16, 700, tons of ore daily. From this tonnage 363,400 pounds of refined Lake Copper are produced in various shapes as specified by the customer. The following paper explains the geology of the ore body and briefly outlines present mining methods. It enumerates the reasons for considering longwall mining of a hardrock* ore body and the preliminary investigations leading to the decision to undertake the initial test panel. Selection of the initial test panel location is covered in detail. Equipment choice and reasons for that choice are described as well as selection and training of personnel.

Jan 1, 1964

By R. K. Rajamani

The theoretical model based on fluid mechanics, in conjunction with the laser-Doppler velocimetry (LDV) measurements, elucidate the size-classification mechanisms in an industrial hydrocyclone. The model has no adjustable parameters and involves solving the Navier-Stokes equations to predict the liquid-phase velocities. The spatial-concentration gradients were determined considering the particle phase in the Lagrangian frame and the classification curve was determined by balancing the forces acting on the particle. The force balance requires liquid velocities, which in turn depend on the local volumetric concentration of the particles. Hence, complete modeling work involves coupling both the concentration and liquid-phase velocity calculations until convergence is reached. Finally, the experimental and predicted classification curves were presented for 250-mm hydrocyclone operating at high-percent solids.

Jan 1, 1994

By Fredrick C. Kruger

We can confidently predict such obvious long-term trends affecting the minerals industry as - increasing consumption, exhaustion of easily discovered near-surface ores, and sharp limitations upon open pit mining by environmental considerations. There- fore, we must intensify the exploration for, and the development and exploitation of, deep bodies of potash and other ores. This paper examines the state of the art of the search for, and the evaluation of, potash from both a geological bias and a mining practicability. The use of indirect geological methods and geophysical techniques, followed by expensive deep drilling, are the conventional approach to evaluation and development of mining plans. The geologist and the geophysicist will have to find ways to perform both of these tasks better and cheaper.

Jan 1, 1973

By M. J. Blattman

The problem of measuring the amount of rock removed during a given time interval is faced by most milling operations. Many methods have been developed with varying degrees of success, dependent upon the mining method and the availability of usable data. The Rosebud Mine has been in production for nearly two years, employing several techniques to estimate monthly production from underground production stopes. The use of three-dimensional solids generated from survey data has greatly improved the reliability and confidence of monthly production reports. The authors will summarize the methodology currently being utilized at Rosebud.

Jan 1, 1999

By Edmund J. Flynn

My subject Is Industrial Relations. Thus, I may appear as an intruder at this annual meeting of the Society of Mining Engineers. But I am no more an intruder here than is Industrial Relations in the day-to-day functioning of an engineer either in a staff or a line job. Engineers deal with people, as well as with blueprints, organizational charts, production data, etc. Where you have people, you have emotions, gripes, wants - real or imagined. Or you may just need some people or, at the other end of the pole, you may want to free yourself of people. But whether it is the wants or the needs, the pleasant or the unpleasant aspects of dealing with people, an Industrial Relations Department within an organization is there to help with these human relationships. This is the point for a definition of terns. Reference has just been made to "dealing with people? and to "human relations." This is, precisely the area in which Industrial Relations operates in the western Mining Divisions of Kennecott. In other organizations, what we refer to as Industrial Relations, may be called personnel relations, personnel administration, employee relations, or labor management relations. In our opinion the term Industrial Relations is best descriptive of the activity because it embraces the broad field of human behavior, reactions and satisfactions growing out of an individual?s entire employment relationship including his hiring, his lifetime on the job, and his termination. This is an individual?s industrial life. However, despite the use of the word "industrial", we are ever conscious that Industrial Relations is limited to human relations. Operational activities and decisions relating to the mining, milling, smelting and refining processes are for the line organization. The Industrial Relations interest in these line organizations activities and decisions relates only to the impact they nay have on employees - on people generally within the organization.

Jan 1, 1959

By S. Guo

In this paper, a model for the resin anchor bolt system is developed in which the smooth bar is modeled by using one-dimensional truss elements and the resin annulus is modeled by using axisymmetric elements. These two submodels are combined together and then incorporated into the' existing computer code ROOFBOLT. After this development, all of the components in the resin anchor bolt system including smooth bar, bearing plate and resin annulus can be correctly modeled.

Jan 1, 1995

By Robert S. Hedin, David M. Hyman

Acid mine drainage (AMD) is a common water pollution problem on active and abandoned coal mine sites in the eastern United States. AMD forms when surface mining brings unweathered pyrite-containing rocks to the surface or when deep mining allows oxygen to contact buried pyritic strata. In the absence of neutralizing compounds, the drainage that results can be extremely acidic and contaminated with dissolved iron, manganese, and sulfate. Drainages with pH < 3.0 and concentrations of sulfate greater than 1,000 mg/L, iron greater than 50 mg/L, and manganese greater than 10 mg/L are common. Where water flows through alkaline materials (such as limestone) before surfacing, the drainage is less acidic and occasionally circumneutral, but it can still contain high concentrations of sulfate and metals. Current water quality standards in the United States require that mine discharges have a pH between 6 and 9, total iron concentration less than 3.0 mg/L, and manganese less than 2.0 mg/L. At thousands of active and inactive mine sites, drainage does not meet these standards and is being treated before discharge by the mining company. At thousands of other sites, which were abandoned prior to the enactment of water pollution laws or were operated by companies that have gone bankrupt, untreated AMD is polluting receiving water systems. The standard mine drainage treatment system involves the addition of a1 kal ine chemicals to the water, which raises the pH and cause metals to precipitate in a settling pond. These systems are expensive, often costing tens or hundreds of thousands of dollars per year for chemicals, operation, maintenance, and disposal of the metal- laden sludge. Because the drainage on many sites will likely be contaminated for decades, there is financial incentive to find alternative water treatment systems. In the last five years, many mining companies and engineering firms have experimented with the construction of wetland treatment systems. Very few of the several hundred wetland systems that have been built are performing well enough to justify total abandonment of chemical treatment. Nonetheless, systems continue to be built because the mining companies have found that wetlands can reduce their AMD treatment costs. It is also their hope that further research and development will eventually result in systems that will completely rep1 ace chemical treatment and offer long term performance at minimal cost. The Bureau of Mines has been actively involved, from a research perspective, with this approach to AMD treatment since its inception. In this paper, the status of constructed wetland technology is discussed with respect to the construction and performance of systems, chemical and biological processes that affect AMD chemistry within constructed wetlands, and the future of this technology as perceived by the Bureau of Mines. ORIGINAL OBSERVATIONS The constructed wetland concept has its roots in observations of natural Sphaqnum peat wetlands that received acid mine drainage and, instead of being adversely affected, appeared to cause an amelioration of the polluted water (Huntsman et al. 1978; Wieder and Lang 1982). These observations instigated the idea that wet1 and systems might be used for the intentional treatment of mine drainage. Because the discharge of AMD into a natural wetland is prohibited in the U.S. by several laws, it has been necessary to construct wetlands which act solely as water treatment systems. Initially, most wetland research and construction efforts mimicked the original observations by utilizing Sphaqnum moss and peat. Despite promising laboratory results (Kleinmann et al. 1983; Tarleton et al. 1984; Burris et al. 1984; Gerber et al. 1985), virtually all field tests of Sphasnum-dominated constructed wetlands failed to provide sufficient water treatment for more than several months. Sphasnum proved quite sensitive to the stresses associated with transplanting, abrupt changes in water chemistry, excessive or insufficient water depth, and

Jan 1, 1989

By R. Q. Honaker

Until recently, the application of the Jameson Cell technology in North America has been restricted to minerals processing. Recently, laboratory, pilot-plant and full-scale testing has been conducted to assess the Jameson Cell&apos;s ability to effectively treat fine coal. Based on the data, carrying-capacity relationships have been developed. In addition to its operational simplicity, the Jameson Cell has the ability to provide a separation efficiency near the theoretical separation performance on the basis of ash rejection while achieving a relatively high throughput capacity Tie results obtained from the various fine coal cleaning applications in North America is presented in this publication.

Jan 1, 1999

By Irvine G. Reilly

Results of a preliminary study of the ammoniacal leaching of covellite (CuS) in an aqueous oxidizing system in the presence of a non-miscible organic sulfur solvent are described. Up to 60% of the sulfur can be recovered from the solvent as elemental sulfur 1 while achieving high degrees of solubilization of the mineral. The effects of temperature, particle size, oxygen pressure, ammonia concentration and ammonium ion concentration on the degree of sulfur recovery were investigated. Maximum recoveries were achieved at moderate temperatures and in well-buffered systems, with a large excess ammonia concentration. Oxygen pressure and particle size were found to have little effect on fractional recovery of sulfur. A simple empirical model based on electrochemical theory correlating the effects of some of the parameters cont-rolling the degree of sulfur recovery is presented. The results of this work also confirm that in any proposed reaction mechanism for the oxidative ammoniacal leaching of copper sulfides, the primary oxidation product of the sulfide ion in elemental sulfur.

Jan 1, 1978

By Theodore J. Barrett

[One of the earliest records of pillar removal can be found in the 16th Chapter of Judges in the Old Testament. Here we read where the mighty Sampson removed the pillars from beneath the prison house causing the collapse of the structure resulting in his own death along with the deaths of the 3,000 Philistine occupants. Our problems at the Mi Vida Mine differ somewhat from those of Sampson of old, in that it is our aim first to remove the pillars and get out from under the back before the "house falls in" and, secondly, to remove the pillars without the lose of a single life or without even a single casualty. As of January 15, 1959, the Mi Vida accident record stood at 772 days without a lost-time accident]

Jan 1, 1959

"What is your assessment of the minerals business?My experience with mining has been primarily in the coal sector until about 10 years ago, when I also became heavily involved in the aggregates and industrial minerals sectors. I have also had peripheral involvement through family and partners in the gold sector, with just enough exposure to gold to become fascinated. In 1994, I visited Ghana and considered the possibility of taking an expat assignment at a surface gold mine that had just been started.It is not news that the coal sector in this country has suffered tremendously in recent years. Especially hard hit is the central Appalachian region, where a number of factors combined have had a devastating effect on production, jobs and the economy. These factors include federal regulations affecting coal production and use, higher production costs and decreasing market share of Appalachian coal by the switch from lower sulfur coal in favor of lowercost, higher sulfur coal from the Illinois Basin, as utilities have installed scrubbers to comply with Phase II of the 1990 Clean Air Act Amendments. Nationally, the lower cost of natural gas has been a huge factor affecting coal use. In Kentucky, for example, which exports to other states around 70 percent of its coal, those markets are disappearing, as utilities close coal units in favor of natural gas. This is a structural change in the electricity market, and one that will become more pronounced as federal greenhouse gas regulations are implemented.We often hear the phrase, "the war on coal." While there are certainly a number of market factors affecting coal production and use, this phrase captures a different element that is all too real. The attacks have come from environmental activist groups for many years; from some in the media and, in the last few years, from a White House administration that believes strongly in alternatives to coal. Then, there really is an alternative to coal in the form of the previously untapped unconventional gas reserves that allowed utilities to move away from coal.Coal mining will continue in this country. In fact, it appears that our production is holding fairly steady at about a billion tons a year. And predictions that I have seen indicate this will continue for the next few years. What impact the Environmental Protection Agency’s Clean Power Plan will have beyond 2020 is another question.What do you feel is the future of the minerals industry - near term and longer term?Our society depends on the future of minerals in this country being strong. Near term, we are going through some of the typical cycles. Having also been involved in aggregates during the last few years, the business follows government infrastructure projects, such as highway construction and public and private sector development. Those sectors are heavily dependent upon government spending and a strong economy. Increased spending in those sectors, which appears to be on the horizon, should provide additional market shares for aggregates."

Jan 1, 2014

By D. N. Madge

A survey is given of production scheduling systems currently in use or contemplated for future use in Cominco operations. Emphasis in this presentation is made on the chain of decisions that are made with the help of mathematical programming models. Some attention is devoted to the structural properties of the models.

Jan 1, 1966

By A. Ersoy, M. D. Waller

Because of a shortage of diamonds for the drilling industry in the 1970s, efforts were made to develop synthetic diamonds. The resulting development of polycrystalline diamond compacts (PDC) enabled the evolution of a new generation of rotary-drilling drag bits. Bits based on PDC cutters were very successful in drilling soft, abrasive and medium strength rocks. However, because of their thermal instability, they failed rapidly when drilling hard rocks. Thermally stable diamond (TSD) was then developed for hard-rock drilling. The rate of penetration (ROP) and bit life significantly influence the drilling cost. The ROP and the life of the TSD bits or cutters are affected by a number of complex factors. However, in laboratory testing and infield operations, the principal factors that need to be considered in predicting drilling and wear rates are bit design characteristics, bit operating parameters and the characteristics of the penetrated rock. These characteristics are comprehensively reviewed for both laboratory and field drilling results using TSD bits. Optimization of these parameters increases the drilling rate, prolongs the bit life and reduces the drilling cost.

Jan 1, 1998

By V. B. Achanti

This paper deals with the effect of various bit geometric parameters on failure characteristics of rock material. Improvement of rock cutting efficiency of continuous mining machines has been an interesting research topic for the last few decades. In the current study, an automated rotary rock cutting simulator, duplicating a continuous miner, was utilized to study these parameters in the laboratory. Improvement of bit performance in terms of its life, cutting efficiency, dust production and energy consumption has drawn wide spread attention over the years. Research shows that optimizing bit parameters can result in efficient fragmentation of rock. Indiana limestone rock material was utilized in this study while bit tip angle, bit tip size, bit spacing, depth of cut and cutting velocity of rotary drum were varied to investigate the failure characteristics. The cutting pressure, penetrating pressure and the depth of cut were monitored on the simulator during the cutting process. Air borne dust and settled dust were measured for each experiment. Then, the specific airborne dust and specific energy were determined for the each type of bit. Triaxial tests were carried out to correlate the failure angle of the rock in static case to dynamic cutting process failure. The physical and mechanical properties of the rock were also determined in order to assess their influence on the wear characteristics of each bit.

Jan 1, 1998