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By D. Greene

The close integration of mine planning and mine operation continues to be the goal of mine operators. Depending upon the complexity, size and sophistication of the mine, limited success has been achieved in this area. Despite tremendous strides in the development of computer-aided mine planning, digital plans must usually be converted to error-prone paper maps and physical ground surveys for actual excavation and reclamation. However, advances in global positioning systems (GPSs), operator displays and mobile computers now enable equipment operators to work directly from on-board digital plans. A computer-aided earthmoving system (CAES) offers reduced survey costs, faster field transition time and improved excavation accuracy, coupled with faster, more informed decision making regarding key mining operations.

Jan 1, 2000

By R. C. Jr. Babcock, V. S. Znamensky

The Pyke asbestos deposits were discovered by Kennecott Explorations (Australia) Pty. Ltd. in 1969 during the course of base metal exploration on the South Island of New Zealand. Extensive occurrences of chrysotile asbestos were found associated with the Red Mountain ultramafics in the headwaters of the Pyke River, and to the north and south along the ultramafic belt for a distance of 70 km. Surface evaluation and drilling by Kennecott in 1970 and 1971 identified numerous small deposits of good grade fiber in the Little Red Hills between the Pyke and Barrier Rivers. Additional drilling and three adits have been completed by other companies since that time. The property is presently held by Lime and Marble, Ltd., of Nelson, New Zealand, and Kennecott Explorations (Australia) Pty. Ltd. This chapter presents the regional and local setting of the asbestos deposits, including the geology and nature of mineralization. In addition, the exploration methods used by Kennecott in the discovery and evaluation of these deposits are outlined. Subsequent work by other companies is mentioned, but not de- scribed in detail. This subsequent work did not alter Kennecott's conclusions or produce any serious changes in the interpretation of geology and mineralization. The author acknowledges the contribution of the many employees of Kennecott Explorations (Australia) Pty. Ltd. who have been involved in the project. In particular, thanks go to Ramon Farmer, N.G. Corner, and A.W. McConie, who were responsible for completion of field work and reporting on the project. The responsibility for the conclusions and interpretations of this chapter are solely that of the author and result from his involvement in the discovery of the deposits and management of the exploration program. REGIONAL SETTING Ultramafic rocks on the South Island of New Zealand are thought to be Permian in age and occur between crystaIline and metamorphic continental rocks of Precambrian through Cretaceous age in the west, are thought to have once been part of the Antarctic subcontinent, and the extensive geosynclinal graywacke deposits of the Mesozoic New Zealand geosyncline in the east. They consist of the Dun Mountain ultramafics, a 130 km long segment of ultramafic rocks located at the north end of the South Island, and the Red Mountain ul- tramafics that occur in a zone 200 km long in the south half of the South Island as shown in Fig. 1. These two belts, once contiguous, have been offset a distance of 560 km by the still active Al- pine fault, which is analogous in character and offset to the San Andreas fault of the United States. The ultramafic rocks occur within a sequence of Permotriassic volcanic and sedimentary rocks that probably formed at the eastern margin of the continental plate. The ultramafics appear to be tectonically emplaced between Permian lithologies in the Dun Mountain belt (Coleman, 1966), and at the base of or between Permian volcanics and sediments in the Red Mountain belt. The Permotriassic ultramafic volcanic sequence of the Red Mountain ultramafic belt appears to be a typical ophiolite sequence. Ultramafic rocks, mixed mafic intrusive rocks and volcanics, volcanic rocks, and volcanoclastic sediments occur in apparent superposition from east to west in the area of Red Mountain. Farther south, ultramafic rocks are associated with basaltic volcanic rocks and some sediments, and still farther south are emplaced entirely in sediments. These structural compIications of the normal ophiolite sequence have resulted from the coincidence of Permian subduction, early Mesozoic extension and sedimentation, and Cretaceous subduction along the same plate margin (Landis and Bishop, 1972). The general geology in the area of the Red

Jan 1, 1986

By Shouci Lu, Keji Sun, Dianzuo Wang, Yiqun Li, Chuang Jin

The dephosphorization of iron ore and reduction in Fe loss in process are currently the foremost technological challenges facing the mineral industry of Meishan Iron Ore. These problems can be resolved to a greater extent by an apatite flotation process which depends on selective flotation reagents. The primary objective of this research work is to develop new type of flotation collectors for dephosphorization of weak magnetic iron ore. Detailed discussion is given on the influence of collector dosage, pH, dispersants and pulp temperature on the flotability of apatite, siderite and hematite using the collectors of Oleyl sarcosinate(OSS), Alkyl polyoxyethylene ether phosphate (AEP) and the mixtures of OSS and AEP A key feature of the flotation was the use of the mixtures of OSS and AEP as a selective collector for phosphate. The effects of chemicals and operational variables on the phosphorus flotation from the weak magnetic iron ores have been investigated. The test results shows that floating the phosphorus minerals with new type collectors can reduce the phosphorous content in the flotation concentrate to an acceptable level of less than 0.20% P with increased Fe recovery.

Jan 1, 2002

By R. Karl Zipf, Z. T. Bieniawski

Based on the premise that understanding the fundamental mechanics of fine fragment formation in coal will lead to reducing coal dust problems in mines, a thorough study of the mechanics of crack propagation in coal was undertaken. Two approaches were considered in an attempt to understand and quantify the fracture process as it relates to fine fragment formation. In one approach, theoretical models are used which describe the size of the fracture process zone which may relate to the amount of structural damage and fine fragment formation on the new crack surface. The other approach is based on the relationship between crack tip stress intensity and new surface appearance for mixed mode crack propagation. Preliminary observations with a scanning electron microscope support the premise that fine fragment formation is related to fracture surface appearance and fracture initiation conditions. An experimental program designed to supply the input parameters for these approaches is presently underway. The experimentation features mixed mode fracture toughness testing, using a special mixed mode testing rig, and fracture velocity measurements with a crack propagation gage. The interpretation of this data via the approaches discussed will provide further under- standing of the mechanics of fine fragment formation in coal.

Jan 1, 1986

By Jerry R. Johanson

Introduction Many solids processes that look feasible on paper or even in pilot studies become disasters in full scale. Changes in solids flow characteristics from pilot scale to full scale be- cause of larger solids contact pressures, thermal shocks, or unforeseen temperature excursions often cause full-scale solids flow problems not encountered in the laboratory or pilot studies. Fortunately, proper applications of solids flow principals and solids flow properties measurement at full scale conditions can anticipate the problems and thus provide an accurate basis for full-scale design or existing plant modifications. Solids flow properties The basic solids flow property definitions are given in Table 1 (Johanson, 1966, 1976, 1978, 1985). In this section, the author will discuss each property and its potential for creating full-scale pilot plants. Unconfined yield strength The unconfined yield strength of a bulk solid determines the tendency for cohesive hangups of the solids in the process and is effected by the time at rest, chemical reactions, temperature, liquid content, solids size consist, and phase changes of solids or fluids involved in the process. One of the common mistakes is to consider the solids condition only at the beginning and the end of the process. For example, consider the direct reduction of iron ore. The feed solids are free-flowing, hard lump ore or pellets. The end result is a hard, free-flowing reduced sponge iron lump or pellet. One might conclude that the process involves free-flowing lumps. This conclusion may seem reasonable based on laboratory studies oreven pilot plant studies where solids contact pressures are very low. Unfortunately, during the reduction reactions at high temperatures, the rock or pellets soften and, with solids contact pressures associated with the full-scale plant, may fuse together, thus providing a possible solids hangup in the moving bed reactor not evident in the low pressure pilot scale. Fig. 1 shows some typical unconfined yield strength measurements for pellets as a function of solids contact pressure at various times at rest. Note at low consolidation pressures, generally associated with laboratory or pilot plant studies, the pellets show no strength unless held at rest for an extended time. This will produce a very free-flowing condition in pilot plants that will not exist in the full size reactor.

Jan 1, 1990

By Nolan B. Aughenbaugh

Zoning and environmental restrictions on land usage now make open- pit quarrying more and more difficult, especially near urban areas. One option for quarry operators is to go underground for mineral production. While underground-mining costs are higher than those for open-cut work, there are several compensating advantages. In many cases it is possible to produce the same material underground without affecting land values, and the surface is preserved for industrial, residential, or agricultural purposes. Proper planning can yield underground sites which have great potential value for industrial plants, warehouses, or other business uses. It is essential to plan underground mineral extraction using a three-dimensional modular-room architectural concept to fully exploit secondary space utilization. Prior to the start of underground mining an operator must make a careful geological engineering study to deter- mine the suitability of the deposit and must prepare a plan for safe and economical mining for the purpose of converting to secondary usage.

Jan 1, 1974

By Y. Lin

The objectives of this investigation were to study the zeta potential characteristics of a Powder River Basin coal in water and to study the effects of zeta potential on the agglomeration of coal particles. The electrokinetic measurements show that the zeta potential of the coal is dependent on pH, temperature, coal concentration and contact time with water. The effects of various additives for changing the zeta potential of the coal were also evaluated. It was found that the strength of the coal agglomerates is increased when the zeta potential diminishes. Neutralizing the zeta potential enhances agglomeration. Therefore, it is important to control the zeta potential of coal to achieve optimum performance in coal-particle agglomeration.

Jan 1, 1997

By T. R. Ellis

Many appraisers/valuers believe that the only valuation method available within the cost approach category for real property appraisal is the depreciated replacement cost method. Some valuation and financial reporting standards setters also believe the same. This paper introduces the minerals appraiser to a number of useful methods for mineral property appraisal that are based primarily on the principle of contribution to value, the predominant economic principle in the cost approach. Most of these cost approach methods discussed are primarily for use in valuation of exploration tracts and resource properties that have no defined reserves. However, the powerful rural cost method can be used to calculate the contribution of categories of resources, reserves and other property components to the value of a mineral property. This method can be applied to mineral properties at all stages of development, including producing properties. The author reasons that standards and regulations pertaining to real property valuation should be modified, and underlying principles should be expanded, so as not to inhibit appropriate application of these cost approach methods.

Jan 1, 2011

By A. Sfougaris

A study on fauna distribution and abundance is being conducted in the Giona Mountain, in central Greece, area of bauxite mining. The specific aims of the study are: a) to estimate and map the distribution of mammals, and especially of the Balkan chamois, b) to estimate and map the distribution and abundance of breeding birds, c) to count the bird species using the area during spring and autumn migration and winter, d) to update the list of mammal and bird species of the mountain, with emphasis on rare and endangered ones, according to 79/409, 92/43 EU Directives and other relevant conventions, e) to compare the bauxite mining areas and species distribution and assess the possible overlap and compatibility of mining activities - species conservation, f) to assess the possible habitat loss due to planned mining activities. All estimations of mammal species distribution and abundance are being carried out by fieldwork using spotlight during the night along selected routes. Especially for chamois, line transects and vantage points with the aid of telescopes and binoculars are being used. Birds are being counted with the point count method in randomly selected plots distributed in all available habitat types and altitudes. The species distribution and mining areas will appear on thematic maps with the aid of a geographical information system (GIS). Finally, solutions for environmentally compatible mining activity in the area will be proposed.

Jan 1, 2007

By C. Rutter, S. Nelson

"Climax Molybdenum Company’s Henderson Mine, owned by Freeport McMoRan Inc., is a panel caving molybdenum mine located 69 km west of Denver, Colorado. The mine utilizes long interconnected ore passes as part of the ore flow system. Knowing the approximate level of ore in these ore passes is beneficial for preventing increased dust concentrations in various production areas, as well as scheduling truck loading operations. Level monitoring has been achieved by using a strain gauge placed on the steel structure of the truck chute, an amplifier and a Programmable Logic Controller. This paper explains the concepts and limitations associated with using strain gauges for ore pass monitoring as well as applying proactive dust prevention and level monitoring interfaces. INTRODUCTION The Henderson Mine, located 69 km west of Denver, Colorado, is an underground molybdenum mine which uses a panel caving process to produce 18,000 tonnes per day currently. This process involves dumping ore down a series of interconnected ore passes leading to truck chutes. Trucks use these chutes to load ore and deliver this ore to an underground crusher. If ore is pulled below the lowest intercept of these ore passes, a ventilation pressure imbalance occurs which generates a large amount of dust on the levels where ore is being loaded into the tops of the ore pass. When a dust event occurs, work must be stopped until the dust settles. Once the dust settles the ore passes must be filled significantly before trucks can start pulling from the corresponding chute. This downtime and unplanned work due to dust can be avoided if the approximate ore pass levels are known. Strain gauges have been installed and tested on a truck chute at the Henderson Mine and the results of these tests have led to a series of concepts in using strain gauges to monitor ore pass levels. This paper explores these concepts and corresponding limitations and explains how the application of ore pass monitoring can be achieved with the use of strain gauges. Ore Pass and Ventilation Pressure Imbalance Overview At the Henderson Mine, there are typically two or four ore passes in different drifts that combine into one bin to create an ore pass complex as shown in Figure 1. When the level of ore is at or below the 7210 intercept (I82W), four drifts have a ventilation connection to each other and the 7655 exhaust level. A “piston effect” is created each time a bucket of muck is dumped down the ore pass. Figure 2 illustrates this phenomenon: as the loader in 621 dumps a bucket down the ore pass, the muck pushes the air in the ore pass down the 82A leg and back up the 82B leg which generates a large amount of dust. The bin regulators on 7655 cannot be opened enough to allow for this surge of air to be relieved onto the exhaust level and the dust ends up exhausting into the 625 and 627 drifts."

Jan 1, 2018

By Slobodan Vujic, Goran Cirovic, Dragan Radojevic

Mine production systems (MPS) are characterized, more or less, by the following properties: uncertainty, subjectivity, impreciseness, polysemy, instability, indefiniteness and lack of data. From modern study aspect these MPS mathematically belong to the class of fuzzy systems. With this in mind, the usage of fuzzy sets is recommended as a methodology that treats impreciseness, indefiniteness and complexity of mine production systems in a satisfactory manner. Fuzzy modelling, discussed in this pa- per, is applied as a mathematical implement. The objective of the paper was to show production optimization in practice on the ex- ample of bauxite open pits where fuzzy linear programming (FLP) was used following the criterion per income. The variables in criterion function are linguistic variables while both variables and variable restrictions are presented by triangular fuzzy numbers (TFN). The term "satisfactory income" presented through triangle fuzzy numbers was introduced instead of "maximizing the income". sensitivity of the obtained solutions has been analysed

Jan 1, 1996

By W. White

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the author elect, he may distribute copies at the time of the Symposium.

Jan 1, 1986

By P. Mousset-Jones, F. Calizaya

Ultrasonic anemometry is a relatively new method of measuring the air velocity in underground excavations and is not widely used. The method has been mainly used for surface applications, such as meteorology and fluid flow measurement. Several instruments were looked at to determine their applicability for continuous underground monitoring systems. The units fall into two main categories: variable distance units and fined distance units. The method relies on the acceleration and deceleration of ultrasonic pulses transmitted through a moving airstream. This study presents some of the results of the testing of variable and fixed distance ultrasonic anemometers in a wind tunnel and a mine drift.

Jan 1, 1995

By C. Tsamantaki

Water-bentonite suspensions exhibit a yield stress which is defined as the minimum applied stress for flow. Considerable debate exists about the yield stress being a material property, hence different measuring methods should give similar answers, but several investigators have demonstrated that it is an engineering reality. Yield stress is normally estimated indirectly from the rheogram obtained with a viscometer following an extrapolation to zero shear rate (the dynamic yield stress), but the technique may be prone to errors because of slip flow. Direct measurements, not prone to such errors, rely on an independent assessment of the yield stress, normally carried out with the vane method (the static yield stress). In this paper results are presented and compared regarding the yield stress of 14 different water-bentonite suspensions measured using both the direct and the indirect methods. In order to obtain a wide range of yield stress values, two different types and two concentrations of bentonite at various pH were tested. Rheological data were obtained using a rotational speed viscometer and a yield stress vane measuring device. Measured vane yield stress values ranged from 5 Pa to 83 Pa. Rheological data collected with the rotating viscometer were fitted using various conventional techniques (interpolation, linear and non-linear regression analysis) as well as using a golden section yield stress search methodology based on Herschel-Bulkley model, developed in house. The vane instrument measures directly the yield stress of the suspensions and requires no further data handling. A comparison of the measured values of the yield stress with the direct and the indirect method is then made for the water-bentonite samples. Not very large differences are observed among different techniques and the variations are discussed. Similar data from literature are also analyzed and the comparison shows that differences on the various estimation methods are much larger than the differences observed in this study.

Jan 1, 2006

By Jerry Grott

Southwest Salt Company is solution mining the Luke Salt Body of probable late Miocene age. The discovery hole, from which the first core was recovered, was drilled in 1968. The deposit was encountered at a depth of 880 feet, and the bit was still in salt at the bottom-hole depth of 4,500 feet. The solar ponds, developed on land formerly dedicated to agriculture, have an annual capacity of about 90,000 tons. Because land values are very high, mining rates and procedures are governed by the need for near-saturated brine to minimize land requirements. Because of the frequency of dust storms, the salt operation uses a unique wet-harvesting method. Most inventory is kept in the ponds under brine and harvested only a few days before shipment. Studies of the nature of crystal growth and the distribution of windblown and brine impurities led to the development of procedures for processing salt of high chemical purity and low insolubles content. Chemical purity exceeds that of most salt produced in fuel-fired evaporators. Salt is shipped from Phoenix as tar east as west Texas and as far west as central California. Occasional shipments have been made to Hawaii and Alaska.

Jan 1, 1987

By D. W. Park

Underground openings resulting from coal mining activities have been a serious cause of subsidence problems in the Warrior coalfield of Alabama, which is the 11th largest coal-producing state in the United States (National Coal Association, 1986). The problem will be even more serious in the future because 17 Gt (19 billion st) of Alabama's 22 Gt (24 billion st) of coal reserves are classified as an under- ground resource (Tolson et al., 1982). Subsidence data in this area has been scarce com- pared with other coalfields (Conroy, 1980; Dunrud and Osterwald, 1980; Gentry and Able, 1978; Hunt, 1979; King and Gentry, 1979). This paper discusses the results of a study of subsidence overlying two longwall mines that contrast each other. One of them (Mine #1) is a shallow longwall mine where the coal strength is very high, and the other mine (Mine #2) is extremely deep with a low strength of coal.

Jan 1, 1987

By H. E. Rudi

The advent of open nit mining permitted the development and processing of minerals never before thought possible. New equipment was needed; new techniques were devised; new methods were called for. This development and acquisition of new techniques, methods and equipment did not, however, stir the souls of our industry and educational leaders sufficiently to a recognition of the problem of people, especially the future development of the people needed in open-pit mining. The people problem has been and will be with us as long as there are two of them. The development of people will be required for the same reason. The problem of developing future personnel for open-pit mining is not what must be developed; that is known to all of us and can be briefly stated ashore and better of everything." As I see it, the real problem lies in determining (1) what personnel are really critical, (2) why are they critical and (3) how can we develop them.

Jan 1, 1965

By C. E. Jordan, B. J. Scheiner

The Bureau of Mines conducted research on the flotation hydrodynamics of fine particle flotation to improve the flotation efficiency in our domestic minerals industry. The turbulent fluid velocity profile was measured in various flotation cells at different levels of dissipation energy. The importance of dissipation energy and bubble size within the flotation cells for the flotation response of a chalcopyrite ore was evaluated. Both increased turbulent fluid flow and fine size bubbles improved the flotation rate of fine size chalcopyrite particles.

Jan 1, 1989

By G. Johnston, P. K. Chatterjee, S. Holguin

M. Gershon The article is an excellent one, providing a basis for the conduct of the major tasks in underground mine planning and scheduling. I object to only one word. Since that word is featured in the title, it is a strong objection. The word used erroneously is optimization. There is no optimization performed in the article. By definition, an optimization is an approach that yields the best of all possible solutions. We can limit this definition to its narrowest sense, the optimization techniques of operations research such as linear programming, or broaden it to include less sophisticated search procedures that find the best mine plan or schedule. No such claim is made in the article. No optimization of any kind is performed. The major tool used is a simulation, which, in truth, is probably more appropriate for this problem than any optimization. But simulation does not optimize. It only allows for quick evaluation of many options, leading to the selection of the best plan "of those tried," not "of all possible plans." This article, of course, is not the first mining paper to make this error. It seems that the word optimization is used more to impress people than to refer to any act of optimizing. It is used in a way that implies "try to optimize"or "come close to optimize," but not to really do it. It is usually appropriate to quietly ignore this error. But when Dr. Chatterjee, who has done so much good work in true optimization projects and whose work I have come to admire, makes such an error, it is time to publicly dispute it. Having discussed this very point with him in the past, I am sure that he will agree. If he can support this position in his response, perhaps people will start to listen and we can reduce the number of false claims of optimization. This should be easy for him in this case since the approach he used, simulation, is the more appropriate one anyway.

Jan 8, 1988

By R. L. Grayson, N. P. Reddy, D. A. Kinzler, S. Yuan, W. R. Myers, R. A. Wells

An examination was conducted on the impact of roof conditions and the mining cycle in determining a representative respirable mass concentration at the mid-shearer location on a longwall panel. Multiple personal gravimetric dust samplers, operated at a flow rate of 2.0 lpm, were used at different locations along the face to isolate the concentrations and variances associated with good and bad roof conditions under both the cutting and cleaning mode of operation. The number of samples needed to estimate the population variance at a given confidence level was analyzed. In addition, the statistical analysis showed that the coefficient of variation of dust concentrations at different locations and under different conditions ranged from 0.185 to 0.475, with an average value of 0.283. The estimates of the average dust concentration for a shift and the variance of the dust concentrations were calculated. A total of 48 data points were available for an [a x b] factorial ANOVA (analysis of variance). The estimates of the variance components were determined. The results from F-tests indicated that both the roof conditions and mining operations had a significant effect on the respirable dust concentration. There was no significant interaction effect between mining operations and roof conditions. In conclusion, this study shows that not only should sampling and analytical errors be considered in determining the required number of samples for a good estimate of the long-range exposures of miners, but also fluctuations of concentrations due to mining operations and geological conditions should be taken into account.

Jan 1, 1991