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By Edward C. Heistermann

The Falkirk Mining Company, a wholly owned subsidiary of The North American Coal Corporation, is located 80 kilometers (50 miles) north of Bismarck, North Dakota. Falkirk is under contract to provide 5.08 mil- lion tonnes (5.6 million short tons) annually to the Coal Creek Generating Station, an 1100 mega- watt electric plant owned by the Cooperative and United Power Associations of Minnesota. Coal Creek is located 2.4 kilometers (1 ½ miles) south of the Mine. Electricity from the plant is transmitted to rural electric customers in Minnesota via a 400-kilovolt D.C. power line.

Jan 1, 1982

By E. DeLilia

For the past 30 years, surface mines have moved toward more highly mechanized, automatic systems that continuously mine overburden and ore to in-crease productivity, lower operating costs and minimize manpower needs. To achieve these goals, mine operators must be involved in every step of the machine procurement process. Several factors are involved in making the machines operate economically and efficiently: ? Prudent engineering. ? Proper planning. ? Realistic feasibility studies. ? Effective specification. ? Thorough training of the mine personnel.

Jan 1, 1995

By Rob Herr, Irwan Halim, Heather Marsh

This project will expand sanitary sewer within the City of Columbus. It consists of 2.5 mile long, 72-inch finished diameter pipe grouted inside 10.8-foot diameter tunnel excavation in shale. This paper describes the multi-faceted geotechnical exploration to minimize the underground risks. The tunnel will cross below a buried valley with minimum cover of highly weathered rock. The risk mitigation to cross the valley includes contingencies and cost allowances. Provisions to prevent impact on adjacent groundwater resources will be described. Latest construction updates will be provided including contractor alternate shaft support and pre-excavation probing to mitigate tunneling risk below the valley.

Jun 23, 2024

By Jr. Wallace

This paper describes the importance of mine ventilation and air conditioning in the operation of a nuclear waste repository. It discusses the impact of ventilation on determining the number and size of shafts and access drifts to and within a repository horizon. The paper also describes the need to maintain separate ventilation systems for waste emplacement and construction operations. The requirement to have filtration capabilities for exhaust air from waste emplacement areas is discussed. Because radioactive high level waste will induce high temperatures in the emplacement drifts, the ability to cool an emplacement drift for re-entry requirements is important. The paper discusses strategies to cool an emplacement drift and the possibility of using continuous airflow to control temperatures in these drifts.

Jan 1, 1991

By W. Burger

For the development of deep, hard rock, mines fast access to the orebody is critical. In some cases the mineralized area is more than 1,500 m (5,000 ft) below surface. Excavation of shafts or declines is typically on the critical path of the project schedule. Saving time on those activities can significantly increase the net present value of the mining project. Mechanical excavation methods are a step-change in excavation performance and labor safety compared to drill-and-blast operations. In hard rock conditions, roadheaders cannot be used effectively, so disc cutting is the first choice. For excavation of declines, tunnel boring machines (TBM) can be used in many cases. These provide, in certain rock conditions, considerably higher production rates com-pared to drill-and-blast excavation. Herrenknecht AG has developed a vertical shaft sinking machine (VSM) that is able to excavate shallow shafts in soil and medium soft rock. The ground is excavated by a roadheader boom. The muck is removed by a slurry system or a pneumatic system in combination with hoisting of skips. These machines have been applied successfully on shafts down to 100 m (300 ft). A pre-sink for a deep mine shaft has been excavated by this technology. For deep, hard rock shafts, a new shaft boring system has been developed by Herrenknecht AG in collaboration with Rio Tinto. Based on proven technologies, the system uses a unique arrangement of existing proven technologies. The system integrates excavation, mucking, primary rock support, installation of the final lining and shaft infrastructure. This new system improves the health and safety of shaft construction. Detailed performance estimates indicate significantly higher shaft construction rates are possible compared to conventional shaft sinking methods.

Jun 1, 2010

By J. C. Danza Errico

The bauxite deposits on the Pocos de Caldas Plateau in the state of Minas Gerais, Brazil, were formed by the differential weathering and leaching of alcaline rocks in a ring structure. Their action on steep topography formed heterogeneous ore posture and chemical grades. Variographic analysis of several of these deposits show nested structures that are probably related to ore genesis. Kriged ore reserves estimation are presented with emphasis on the data pro cessing method that was employed. Programs were written in APL. Its intrinsic use of matrices contributed to faster programming and less computer time. In many cases looping was eliminated. The high resolution graphic resourses of APL. workspace facilitated programming of variogram analysis, fitting, and regularization. APL sub-routines are presented for variogram calculation and kriging.

Jan 1, 1986

By R. B. Tippin

The material balance computer program (MAT-BAL) developed at the Minerals Resource Research Center of the University of Minnesota, has been used in conjunction with routine process profile samples taken in the potash compaction plant at Great Salt Lake Minerals and Chemicals Corporation, Ogden, Utah. In this manner, a uniform data base is being established for the process, and selected key indicators are used for decisions in plant operation and maintenance. With present emphasis on improving product quality and increasing production rates, the standard data base system provides a means of measuring results from test programs to optimize the circuit. The development and application of this process control method is discussed. The compaction plant computer-assisted data base has been in existence for only two years, but it has made significant contributions to the knowledge of the process and continues to assist in monitoring the plant performance. It is anticipated that the material balance program will be adapted to the GSL flotation plant in 1979, and to other circuits in the potassium sulfate chemical plant.

Jan 1, 1979

By Mark P. Walsh

In recent years in situ leach mining has emerged as a viable technology for the recovery of uranium from strata in South Texas which contain relatively low concentrations of uranium ore. Because the ore bodies lie within groundwater aquifers, a significant determinant in the economics is the requirement that such aquifers be protected from contaminantion. Since ammonia is one of the constituents of the leach solutions now being field tested, one environ- mental problem to be resolved is the removal of ammonia at the end of mining. A second related question is the fate of the ammonia which is not removed by the restoration procedure. This paper considers the displacement and migration of ammonium in a flowing electrolyte with concomitant ion exchange. The ion exchange is an important feature since, during the solution mining phase, ammonium saturates the mineral exchange sites and must be removed from these sites. A mathematical model is used to simulate this process and the model is tested against the results of laboratory experiments. It is found that the simulations are adequate if an appropriate selection of parameters is made. The model is then used to investigate the effect of cation composition and concentration of the restoration medium as well as dispersion on the overall effectiveness of the process. It is concluded that increasing the concentration of monovalent ions in a solution containing a mixture of both monovalent and divalent ions decreases the adsorption selectivity of the divalent ions with respect to all monovalent ions including ammonium. Thus increasing the ionic concentration of a restoration fluid by increasing the concentration of a nonselectively adsorbed (with respect to ammonium) ion may have a very limited benefit. Dispersion attending the flow of fluids in a porous medium is also shown to be an important factor. The effect of dispersion can greatly reduce the benefits of having a displacing cation which is adsorbed selectively with respect to ammonium. Since dispersion increases almost linearly with fluid velocity, an optimum displacement rate may exist.

Jan 1, 1979

By K. Fountain

In Novemeber of last year I visited a mica mine in Hunan Province, China. For nine months , we had been trying to sell Chinese mica to a customer in Belgium. Talking to the customer was like negotitating with a stone wall. The buyer refused to communicate any -thing other than his steadfast refusal to consider Chinese mica. He would not advise us what he wanted, what specifications or grades. He would give no indication if our price at market, or reasonable, or totally out to lunch. He would not even accept samples. It took no genius to guess that the mica buyer had at some time in the past bought a shipment of Chinese mica and had received a disaster. I invited the mica mine in Hunan in order to see for myself what could be done - without massive investment in equipment and instruments - to upgrade the quality of the mica for export. We had seen this type of customer reaction before. One disgruntled customer who had pur¬chased pigment grade barites direct from China ranted and raved about unreliable and inconsistent quality. It did no good to explain to him that China is a big country, with hundreds of mines scattered throughout many areas, each producing a different product. Our further explanation that Chinese export organizations also varied in degree and efficiency of customer service fell on deaf ears. Samples had no effect on his perception. Eventually we showed him photoraphs of two mountains of pigment grade barites. One lot was our sales of pigment barites to a major European minerals processor. Our Chinese barites stood proudly white and beautiful next to a hill of other material which now appeared at best mediocre and dull by comparison, and which the buyer had decided to reject after he received our Chinese barites. Finally the customer was sufficiently impressed to look seriously at our guaranteed specification and the outturn analysis performed by our other customer.

Jan 1, 1987

"The National Mining Hall of Fame and Museum (NMHFM) announced the 2017 National Mining Hall of Fame inductees. This year’s inductees, selected by the National Mining Hall of Fame’s Board of Governors, represent exploration and extraction of new frontiers, environmental stewardship, leadership in formulating U.S. mineral policy, education, and research and development, including the use of computers in planning, designing and managing mineral industry operations. The contributions of these individuals have undoubtedly had a significant and lasting impact on the mineral and mining industry. These individuals were selected for being visionary leaders, innovators, authors, pioneers in corporate social responsibility, and long-standing advocates for the U.S. mining industry.Dr. Thomas V. Falkie, Leonard Harris, Dr. Vincent E. McKelvey, and Gordon R. Parker will join 236 other mining industry luminaries when formally inducted into the National Mining Hall of Fame on Sept. 23, 2017. The 30th Annual Induction Banquet and Ceremony will be held at the Pinnacle Club, Grand Hyatt Hotel in Denver, CO.2017 National Mining Hall of Fame inductees:Dr. Thomas V. Falkie — In a career spanning six decades, Falkie’s accomplishments in industry, academia, government and professional societies demonstrate a pattern of integrity and sustained excellence. His gravitas and management style left highly favorable impressions in every position he held. He was the chairman and president of Berwind Natural Resources Corp.; President of SME; President of the American Institute of Mining, Metallurgy and Petroleum Engineers; Director of the U.S. Bureau of Mines and head of the Department of Mineral Engineering at the Pennsylvania State University. He played major leadership roles in the American Mining Congress, National Coal Association, Mining and Metallurgical Society of America, and the National Mining Association. He served on the board of directors of Foote Minerals and Cyprus-Amax and was very active in the National Academy of Engineering, the SME Foundation and the National Mining Hall of Fame and Museum.Leonard Harris — A highly regarded metallurgist and business executive, Leonard (Len) Harris may be most remembered for the heart he has for the people whose lives were touched by his career. For more than six decades, Harris has been a true pioneer in corporate social responsibility, leading companies to understand that doing the right thing for the local people is also the best path to business success. After an early career in Australia and Ghana, Harris moved to Peru in 1955 to join Cerro de Pasco Corp., owner of several mines with one of the most complex metallurgical operations in the world. Harris was quickly promoted through multiple positions and was ultimately named director of metallurgy."

Jan 8, 2017

By Nelson M. Solow

Raise boring of mine ventilation shafts in many cases offers a lower cost and higher speed method of construction in comparison to conventional shaft sinking. Where underground access is available for raise boring the potential savings indicate that raise boring should be considered as an alternative to other methods. Raise boring machines are currently in use which have the capability for reaming shafts up to twenty feet in diameter, depending on the strata and depth. These large capacity machines make it possible to consider raise bored shafts for moving large volumes of air. Although we will consider here only ventilation shafts, raise boring should also be considered for men and material shafts. When the mine planner has determined the volume of air required through a shaft at a particular location he is faced with the problem of selecting the shaft size. The principal factors in optimizing the shaft size are the construction costs for the shaft 'and the power cost to move the air through the shaft. The larger diameter the' shaft is the more it costs to construct, but for a given volume of air the power required (cost) becomes lower as the diameter increases. The construction cost is paid only once, when the shaft is constructed. The power costs, however, are paid throughout the life of the shaft. Methods of optimizing air shaft size found in the literature (References 1 and 2) amortize the construction cost and include it in the average annual cost of operating the airshaft. These methods derive a formula for the average annual cost vs. shaft size and de-rive the formula to compute the optimum size for a given air flow rate. It is, however, desirable to take into account tax considera-

Jan 1, 1977

By R. D. Grove

The control of Florida phosphate flotation plants is largely based on the visual observations of experienced operators, both in recognizing good and bad froth conditions and in making judgments about the composition of feed, concentrate and tailing streams. Chemical analyses lag the process by at least two hours and therefore only assist in recalibrating the operators' vision when major deviations occur. An image analysis system has been developed by IMC Fertilizer to improve upon the accuracy and precision of the composition estimation process. It still relies upon the operator taking a representative sample, but provides a measurement in about 15 minutes after that sample is obtained. This paper describes the system and its use and presents comparative results for various process streams.

Jan 1, 1993

By Hugh D. Olmstead

Typical operations necessary to develop oil and gas reservoirs are reviewed, including exploration, drilling, cementing, completion, work over, sand control, stimulation, enhanced recovery and production. The role of industrial minerals in these operations is described. Some of the opportunities and problems affecting increased use of industrial minerals in drilling and stimulation are discussed.

Jan 1, 1983

By E. R. DeMen

In late 1965 General Mills announced the availability of a new liquid ion exchange reagent, LIX®-64, for the recovery of copper from various solutions, such as dump leach liquors. Acceptance of this material by the copper industry has been gratifying. A number of pilot plants have been operated, and at this writing there are four commercial plants either in operation or under construction. The properties and operating characteristics of this reagent have been described in previous papers.1,2 LIX-64 is quite effective and selective for copper extractions although partially limited in pH ranges, losing extraction efficiency as the acidity of the feed solution increases to below pH 1.0. Also, the LIX-64 content in the kerosine carrier was limited to about 10 volume percent (except for special cases) because of rapidly decreasing phase disengagement rates above this content. This in turn led to large plant capital costs, as the organic flow rates had to be in- creased (rather than LIX-64 content) to extract the copper from high content liquors. This was true in all circuits where the feed copper content ran above 2.0 g/l copper. A reagent was needed which would extract copper from more acidic liquors (or higher copper content liquors) and which exhibited improved phase disengagement characteristics with reagent contents up to 30 volume percent. General Mills is pleased to announce the availability in commercial quantities of a new and improved reagent, L+-64~. This reagent broadens the pH range in which copper can be extracted, and exhibits superior phase disengagement characteristics. The improvement in the reagent has been noted in laboratory circuits, as well as pilot plant runs and commercial operations.

Jan 1, 1970

By Y. Luo

Surface subsidence process due to underground coal mining often has the potential to cause problems to buried pipelines. In this paper, a technique for assessing the stress level on a subsidence-affected pipeline is introduced. The main contributors for the stresses on the pipelines are identified. Mitigation techniques for reducing the stress on the pipeline have been proposed and successfully tested.

Jan 1, 1997

By Ben W. Burdett

The operation of an electrolytic refining tank house is an art as well as a science. If the electro-refining industry is to progress, a better understanding of the refining process is necessary. This would help to reduce the amount of training necessary to produce competent tank house operators who, in turn, would be able to increase both quantity and quality of the tank house product. To aid in understanding this process, quantitative relationships between the critical tank house variables must be established. The inherent major contributor to inefficiency in most tank houses is short circuits. By quantifying the effect of short circuits on each of the other variables in the system, as well as their effect on over- all system performance, better decisions regarding manpower allocation can be made. Current distribution under short circuit conditions, which has always been somewhat of a mystery, can be studied in detail. The relative importance of electrolyte balance, proper anode-cathode spacing, low contact resistance at points of electrical connection, and other system variables can be determined, With a better understanding of these variables, the steps necessary to increase current efficiency are more easily defined. Relationships between most of these variables are described in qualitative terms in the literature, but quantitative relationships between tank house variables have never been established. A realistic mathematical model of the tank house could be used to test the effect of variations in a single variable on other variables in the system, and thus define the quantitative relationships between tank house variables. It is not the purpose of this paper to establish these relationships, but to describe a recently developed model that can assist in their establishment. A computer program implementing this model has been applied to examine the effect of short circuits on overall current distribution. Some of the results are given here as examples of the utility of this program.

Jan 1, 1973

By S. Afrouz, C. Keles, W. R. Reed, E. Sarver, T. Akinseye, A. Greth, L. Pan, F. Animah

The resurgence of severe lung disease among U.S. coal miners has not only highlighted the need for improved dust controls, but also the need for an improved understanding of dust characteristics and monitoring strategies [1]. Following up on prior work by the National Institute of Occupational Safety and Health (NIOSH) to demonstrate a novel wet dust collection system on a roof bolter [2], the current study explores the effect of that system on dust characteristics and uses interlaboratory comparisons to comment on analytical methods. Results indicate the wet system did not appreciably affect the composition or size of respirable dust in the vicinity of the operating roof bolter. However, the system does appear to have substantial benefits for the operator. NIOSH has already shown it can reduce the respirable dust mass concentration to which the operator is exposed during dustbox cleanout [2,3], which is a frequent maintenance activity that can re-aerosolize dust, and new results here indicate the silica and silicates content in this dust may also be reduced, thereby reducing the overall hazard. Moreover, regarding analytical methods, excellent correlation was demonstrated between measurements of quartz mass, taken first by NIOSH and then by a university laboratory, using direct-on-filter Fourier transform infrared (FTIR) analysis. This method is the basis for envisioned “end of shift” silica monitoring (quartz is the predominant form of crystalline silica in coal mines) [4]. For particle-level analysis by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), there was more variability in results generated by two independent university laboratories.

Mar 1, 2024

By D. K. Denton, D. F. Scott, T. J. Williams

Spokane Research Center personnel have been investigating the use of seismic tomography to monitor the behavior of a rock mass, de¬tect hazardous ground conditions and assess the mechanical integrity of a rock mass affected by mining. Seismic tomography can be a valuable tool for determining relative stress in deep, >1,220-m (>4,000¬ft), underground pillars. If high¬stress areas are detected, they can be destressed prior to development or they can be avoided High-stress ar¬eas can be monitored with succes¬sive seismic surveys to determine if stress decreases to a level where de¬velopment can be initiated safely. There are several benefits to using seismic tomography to identify high stress in deep underground pillars. The technique is reliable, cost¬effective, efficient and noninvasive. Also, investigators can monitor large rock masses, as well as moni¬tor pillars during the mining cycle. By identifying areas of high stress, engineers will be able to assure that miners are working in a safer envi¬ronment.

Jan 1, 2000

By J. Y. Perez, H. M. Ewoldsen, L. L. Oriard

Near the village of Villarino de los Aires, in the province of Salamanca, Spain, is an existing underground hydroelectric power plant. A major enlargement was undertaken to increase the electrical generating capacity, under a contract awarded to a joint venture of Dragados & Construcciones, S.A., Entrecanales y Tavora, S.A., and S.A. Conrad Zschokke. The enlargement required the excavation of an underground system of tunnels, shafts and chambers adjacent to existing facilities and interconnected with these facilities. The existing machine hall and transformer chamber were both extended, requiring excavation of the rock that constituted the existing end walls of these chambers. The drilling, blasting and excavating of the underground system had to be done without damaging existing underground openings or any of the existing structures, equipment or instrumentation facilities. This required careful control of vibrations, air waves and dust. The joint-venture contractors preferred to use electric blasting methods, if these methods could be implemented in a safe manner. The safety question had to be evaluated carefully. High electrical potentials existed at the site because of the electrical generating and transmitting facilities that could not be shut down. Electrical fields were carefully studied prior to the beginning of the work. This was done both in the underground environment and above the ground surface. Special procedures were followed to ensure safety with

Jan 1, 1974

By J. Edberg

"This article details the use of an alternative testing method to the 2004 "Post-Tensioning Institute (PTI) Recommendations for Prestressed Rock and Soil Anchors" manual’s recommendations for temporary and permanent rock anchors for applications in shafts and tunnels. This method was developed and used for the Black River Tunnel (BRT) project in Lorain, OH as a means to reduce testing time of rock bolts during shaft construction while maintaining a similar level of quality control and assurance. The following sections will detail the project background, subsurface characteristics, shaft construction, the 2004 PTI testing method and associated difficulties, the alternative testing method and conclusions reached.Project backgroundThe city of Lorain is located in north central Ohio on the south shore of Lake Erie, approximately 40 km (25 miles) west of Cleveland and 119 km (74 miles) east of Toledo. The city chose to build a large-diameter storage tunnel and pump station to meet its requirements to reduce sanitary sewer overflows to the nearby Black River. NTH Consultants Ltd. (NTH) was retained by the city’s prime consultant, Malcolm Pirnie Inc. (now the water division of Arcadis), to perform a geotechnical investigation, develop design and construction bid documents for the tunnel and shaft liner systems and ultimately provide oversight assistance during the construction phase of the project.The BRT is an approximately 1,700-m (5,560-ft) long, 7-m (23-ft) diameter rock tunnel to be lined with a 5.8-m (19-ft) inside diameter secondary concrete lining (Fig. 1). The tunnel is designed to accept flow at a new drop shaft (Shaft 3) located on the west side of the Black River, across from the city of Lorain Black River waste water treatment plant (BRWWTP). The tunnel will be dewatered at the south end by a large diameter pump station (Shaft 1) located in the existing Lorain Port Authority Public Boat Launch. Flow from the new pump station will be discharged into an existing shallow interceptor sewer and directed back to the BRWWTP."

Jan 1, 2014