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By Robert C. Freas

The summer joint meeting of the East Tennessee and Carolinas Sections of SME was held in Morristown, TN, on July 29 and 30, 1994. The Friday portion of the meeting began with a field trip to Asarco Inc.'s Young Mine and Mill, one of four mines operated by the company in the Mascot-Jefferson City district. The Young Mill processes ore from two other mines as well as its own, first by heavy media separation and then by standard flotation processes. Zinc concentrates are shipped by truck and barge to an electrolytic refinery in Clarksville, TN. The heavy media rejects and the dolomitic limestone tailings are sold through Asarco subsidiary American Limestone Co. Saturday's technical session, organized by Program Chairman Bob Fulweiler of the Tennessee Division of Geology, provided a review and status report of the zinc industry in Tennessee. This article summarizes papers presented, including one on recent developments in underground blasting.

Jan 1, 1994

By D. R. Schricker

Mine managers rely on their experience, section foreman's daily reports and occasional time studies to make important production, maintenance and forecasting decisions. This information is often subjective and imprecise, consumes expensive engineers time, is often biased and is restricted to short time periods. Managers need better information. Furthermore, if a recently purchased machine is being evaluated, a large increase (>10%) in productivity may be obvious, but small increases are usually masked by other variables. In today's highly competitive markets, cumulative small changes are important, especially since managers have already exhausted most available, obvious avenues of improvement. A technique to separate these charges from effects of other variables and to quantify the target effect is necessary. CSM researchers are addressing this need by developing an intelligent decision support system (IDSS). It provides key production and maintenance information to support management decisions by recognizing patterns in mining machine sensor data and representing knowledge about mine management, operations, layout and equipment. A continuous miner section at Western Fuels-Utah Inc.'s Deserado Mine in Rangely, CO is the test facility for the research. Power transducers located in the sections load center provide kilowatt versus time data from continuous section equipment. The IDSS pattern recognition algorithms classify the kilowatt versus time patterns into individual machine operating modes. It produces an output similar to a typical industrial engineering time study but continuously, automatically and without an engineer in the section. It is relatively easy for a time-study engineer to identify the stop and end points of a cycle element and classify it by looking at the machine and glancing at a stop watch. The problem is that monitoring system hardware and software do not have these unique capabilities. Consequently, IDSS algorithms must automatically define the begin and end points of machine tasks and identify the task by recognizing patterns in kilowatt versus time data. However, many mines have file drawers of time-study type data that are not very useful. So, IDSS contains the knowledge representation subsystem (IDSS/KRS) to produce short reports containing only key information. This is difficult because mine environments continually change and information requirements differ for each management level. Consequently, IDSS/KRS must learn and adapt to new conditions in a dynamic mining environment.

Jan 1, 1990

By N. I. Aziz, B. Srinivasa Rao, R. N. Singh

The control of respirable dust and its subsequent exposure to miners is essential for improved safety in longwall mining. The extensive variation in face conditions and operations of longwall make numerical modelling an attractive approach in both the development and evaluation of dust control devices. Three dimensional finite element computational fluid dynamics code FIDAP was used to model air velocities and the effect of dust control techniques on dust concentrations at a typical longwall face. The effect of shearer body on airflow characteristics in a longwall face was analysed with both antitropal and homotropal ventilation systems. Path traces of particles introduced near the shearer drums was also simulated. Initial modelling results were validated using field trial results at three operating longwall faces. Results of simulations tallied very well with the field results.

Jan 1, 1993

By B. K. Mishra, R. K. Rajamani

This paper focuses on the use of a numerical tool known as the discrete element method (DEM) to study the motion of ball charge in ball mills. DEM is employed to simulate the motion of individual balls. While doing so, the effect of liner design on the grinding performance of the mill is studied. Two important, factors, such as the configuration of the liner and the geometry of the lifting surfaces, are correlated with the overall mill performance. An attempt is made to show the effectiveness of the lifter bars in transmitting power from the mill shell to the interior of the mill, with particular emphasis on large diameter mills.

Jan 1, 1994

By L. Korkiala-Tanttu, M. Rinne, Z. Song

Disposal of mine tailings has been recognized as an unavoidable burden of mining companies and local authorities. Conventional methods dispose mine tailings in a passive manner which hardly generates any value from them. On the other hand, growing local communities close to mines need more infrastructures which require great amounts of raw materials. In view of the above mentioned situation, a novel utilization of mine tailings is explored as alternative material for asphalt pavement, in order to extract more value from mine tailings and solve the high cost of pavement material. Inherent physical properties of the mine tailings were first investigated to find out their availability as pavement material. Then test specimens were made as mixture of the mine tailings and other pavement material to be tested in laboratory. The mine tailing materials presented a considerable potential as asphalt filler for low-volume roads. Furthermore, the limitat

Jan 1, 2011

By Xu Xiaohe, Zhou Jiandong, Luo Shihui, Zhang Liqun

Recently, the research and applications of ES (Expert Systern) have been put forward actively in many mining fields in China. After various ES applications or instances are introduced, the paper has especially focused on the exclusive properties of a mining system different from any other system and the problems of the existing mining ES applications. And a synthesis methodology has been introduced in order to develop a applicable ES application

Jan 1, 1996

By Peter J. Borchardt, Helen M. K. Andersson, Donald A. Bruce

Grouting is a useful engineering tool for tunnels throughout the world. A wide variety of methods and materials are used, reflecting the broad range of geological, hydrogeological, and structural demands. Most tunnel grouting is conducted with cement, which produces acceptable results in appropriate conditions. However, there are cases where such grouts are not practical, but polyurethane grouts can be extremely useful. Regretfully, these grouts are frequently poorly understood, leading to improper application and therefore poor results. This paper provides a fundamental overview of their application, both used individually and in combination with cement. Case histories from Scandinavian practice are cited.

Jan 1, 2001

By R. D. Hamilton, W. J. Miles

In 1987, the International Agency for Research on Cancer designated crystalline silica as a 2A probable carcinogen. As a result, crystalline silica is regulated under the Hazard Communication Standard as a probable carcinogen at a concentration of 0.1% or greater in the workplace. Crystalline silica will be listed as "reasonably anticipated to be a carcinogen" by the National Toxicological Program. This designation of crystalline silica as a probable carcinogen has created major issues for the mineral and chemical producer, including labeling, hazard communications, marketing a material with potential hazard exposure, and potential liability. The State of California also regulates crystalline silica under Proposition 65 in products as a carcinogen, based upon the IARC determination that it is a probable carcinogen. More federal and state regulations are anticipated as a result of the IARC classification of crystalline silica and its subsequent federal regulation. Respirable crystalline silica has been regulated as a hazardous dust for many years by OSHA. This regulation was initiated to prevent silicosis, another occupational disease. OSHA has established monitoring devices for determining the concentration of airborne respirable silica in order to measure exposure to this substance. The accurate determination of the crystalline silica content is critical to dealing with these health risks and regulations. In the past, crystalline silica was considered to be safe and, because of its ubiquitous nature, little effort was made to determine or quantify its presence in most materials. The Hazard Communication Standard requires that a1l products containing 0.1% or greater crystalline silica must be properly labeled for this material and its hazard. Unfortunately, the 0.1% threshold was not chosen on the basis of established analytical capabilities for crystalline silica, but results from general limits for potentially carcinogenic chemicals and substances. Numerous methods have been developed for the determination of crystalline silica in a variety of products. However, these methods are not generally applicable since they must be specific for silica in any of its crystalline states and not just for total silica content. Chemical tests for silica are not difficult and quite accurate at the 0.1% level; however, in addition to its crystalline phases, it occurs in amorphous phases and in a wide variety of crystalline and amorphous silicates. In general, there is little correlation between total silica content and crystalline silica.

Jan 1, 1991

By J. G. Groppo, B. K. Parekh

Eastern US oil shale contains approximately 10 to 12 gallons of oil per ton and 7 to 10% pyritic sulfur. Physical beneficiation of these low grade shales using froth flotation provides a high grade material that makes extraction of oil more economically attractive. The Alabama oil shale used in the present study contained 16.46% organic carbon and 14.5 gallons of oil per ton as determined by Fischer assay. Liberation size of the kerogen was estimated at 10 µm. `Ken-Flote' column flotation technology provided a high grade concentrate containing as much as 60% organic carbon. However, carbon recovery was about 60%. Carbon recovery was improved to 75-85% while maintaining concentrate grades in excess of 40% carbon by providing longer retention time in the column, which facilitated effective bubble-particle collision and attachment.

Jan 1, 1994

By J. David Lowell

The discovery of the Kalamazoo (Arizona) ore body was a comedy of errors and coincidences and luck -as most discoveries probably are. The story began in early 1965 when Quintana Petroleum decided to diversify from petroleum into minerals and decided to do this by the route of minerals exploration. Quintana Petroleum is owned by the Cullen family of Houston and has Geen successful over the years in discovering oilfields. In 1965, the president and general manager was Corbin J. Robertson, son-in-law of Harry Cullen, founder of the company and a famous Texas wildcatter. But, in 1965, Quintana's financial advisors suggested that the company go into several mineral commodities, including copper, with Tucson, AZ, as the jumping-off point for copper exploration, and with a geological consultant (me) as the point man. The stage was now set! (See Fig. 1, location map of the San Manuel District, Arizona.)

Jan 1, 1991

By W. M. Ma, Daniel W. H. Su, K. Centofanti, Yi Luo, W. L. Zhong, Syd S. Peng

NTRODUCTION Surface subsidence monitoring is the most effective means for investigating the nature of, and developing the techniques for pre¬dicting the surface movement and deformation process. However, because of imperfection in survey equipment and field practices, the surface movement data collected from field survey are not error-free. Also due to lack of proper numerical techniques for computing surface deformation from the measured surface move¬ment data, a relatively large portion of the subsidence data col¬lected could not provide information other than surface movement. In a paper by Luo and Peng (1992), the sources and magnitude of errors in the measured surface movements using an electronic total station in subsidence survey are discussed. If the errors in the measured surface movement components are left untreated before calculation for deformation indices (i.e., slope, strain and curva¬ture), the errors will be carried over to the deformation indices and enlarged if improper numerical procedures are used in the calcu¬lation. It should be noticed that in protecting structures affected by ground subsidence, accurate surface deformation indices are much more important than surface movement. In order to improve the accuracy of the collected surface movement data and the calcu¬lated deformation indices, a number of numerical procedures are also proposed in the same paper. The proposed techniques include: a data smoothing technique for data pre-processing; and a number of numerical methods and/or procedures for calculating surface deformation indices from the measured surface movement data. DATA SMOOTHING Because of various factors, the measured surface movement data always contain errors, small or large. In order to better utilize the collected data, a data smoothing method is proposed to correct the errors in the measured movement data. The method uses the same concept as the influence function method (e.g., Knothe, 1957) on which many existing subsidence prediction methods are based. The data smoothing method makes necessary corrections on the measured movement for the point of interest according to not only the measured movement at this point but also those at the surrounding points. The contribution of a surrounding point in making the correction for the point of interest is inversely propor¬tional, in exponential form, to the distance between them. The new magnitude of a movement component at the point of interest (Zi*) is calculated by

Jan 1, 1992

By J. H. Tylczak, R. Blickensderfer, D. J. Singleton

As part of its research on wear of mining and mineral processing equipment, the US Bureau of Mines evaluated the erosion-corrosion characteristics of 12 alloys in phosphoric acid waste water. Tests were conducted on 2- and 5-cm-diam specimen8 in 12- and 60-cm-diam ball mills by grinding phosphate rock in gypsum pond water with an initial pH of 1.6. For comparison, grinding tests also were conducted in tap water. Static corrosion tests in gypsum pond water also were carried out. For all alloys tested, the wear by erosion-corrosion was greater than the sum of erosion plus static corrosion. A low-alloy, high-carbon steel and a high-manganese, nitrided stainless steel were the most cost-effective materials

Jan 1, 1987

By John H. Duke

The success of most attempts to evaluate gold orebodies depends largely on the reliability and availability of representative sampling data and the accuracy of geological interpretation. An accurate prediction of the continuity of geology is paramount to a reliable prediction of gold reserves. Many of the problems encountered in gold mine evaluation and planning revolve around the difficulties in interpreting complex geology from sparse drilling data and the eagerness of mine financiers and promoters to start mining in order to derive an early cash flow. Following a program of sampling, geophysics, mapping and geological interpretation, a conceptual orebody model evolves in the minds of those working on the project. It is this model which is used typically in ore reserve computations and mine planning. Computer modelling techniques to represent and evaluate the conceptual model are now available. The main advantages of using computer modelling methods lie in being able to rapidly evaluate, modify and quantify the conceptual orebody model. Ore zones or domains can be recognised and defined both from geology and sampling results. Once these domains are defined as a series of boundaries, they may be modelled as two dimensional grid surfaces or as wire-framed three dimensional geometries, depending on the complexity of the orebody. It is the definition of these domains which provides the sound geological basis for reserves computation. To estimate reserves it is necessary to determine both volume of ore and grade of ore. The ore volume is calculated within each domain as defined by the confining surfaces or wire-frames. The ore

Jan 1, 1987

By Warren E. Fife

This paper will discuss the application of a continuous miner using a fixed drum milling type cutting head for the underground mining of hard rock and salt ores. Continuous mining machines of the ripper chain cutting head, oscillating milling cutting head and boring arm designs have been used in rock and salt applications with various degrees of success. The large boring arm miners have been successful in potash, trona and salt, but they have not been successful in mining rock materials like iron ore. The main method used in underground mining rock materials is the conventional drilling and blasting the ore from the solid. This is particularly true for the harder, more abrasive copper and iron bearing ores. The softer salt based ores of potash, trona and rock salt can use several underground mining methods depending on seam conditions. Several of these methods use underground coal mining equipment that has been extensively redesigned to adapt it for use in mining noncoal materials. Conventional mining methods employ the use of a universal cutting machine to undercut or topcut the ore body before face drilling and blasting takes place to produce a smooth parting of the ore. The boring arm continuous miner is widely used in underground mining of potash and trona ores. It produces a tunnel with a smooth semicircular contour which results in good rib and roof stability. The ripper chain continuous miner is also widely used in mining the salt based ores of potash, trona and rock salt. They are used more frequently in Europe than in the United States and Canada. Some reasons for using the mechanical mining machines as opposed to the conventional drilling and blasting techniques for mining hard rock ore bodies are the resulting improved rib and roof control, facilitates selective mining of the ore body, and requires less man-

Jan 1, 1974

By T. E. Walsh

Introduction I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too ex

Jan 1, 1980

By M. Kockler, S. J. Jung

Underground operations at the Rain Mine averaged 360 tonne/day (400 ton/day) utilizing underhand drift-and-fill and longhole stoping with delayed fill between 1993 and 2002. Mining from four ore zones produced over 803 800 ore tonnes (886 000 tons) at a grade of 9.32 gm/tonne (0.270 oz/ton). Even though openings in the ore could be as large as at 9 m (30 ft) wide, 30 m (100 ft) high, and over 60 m (200 ft) long, the weak rock surrounding the ore zones restricted development size to 3 m (10 ft) wide by 3.7 m (12 ft) high.

Jan 1, 2004

By Majid Ataeepour, Ernest Y. Baafi

High level programming languages such ass C, FORTRAN and BASIC have been used in the mining industry to simulate truck-shovel systems. In addition, some special languages for simulation such as GASP, GPSS, SLAM, PROOF and SIMAN are commonly used. The most recent simulation system ARENA uses graphical modelling approach as well as animation notion. In this paper, the main elements of ARENA required to perform a truck- shovel simulation and to view the simulation results by means of the model animation are presented. The layout of the haulage system including shovels, trucks and dump sites was generated using draw tool in ARENA. All the components of the haulage system were represented by graphical modules. Animation tool was used to depict the performance of the haulage system as the simulation progressed.

Jan 1, 1996

By Dale R. Ralston, Roy E. Williams, Gerry V. Winter, George L. Bloomsburg

Aquifer. A formation, group of formations, or part of a formation that contains sufficient satu rated permeable material to yield significant quan tities of water to wells and springs. Artesian. Synonymous with confined; see ground water, confined. Capillary fringe. The zone immediately above the water table in which all or some of the interstices are filled with water that is under less than atmospheric pressure and that is continuous with the water below the water table. Conceptual model. A conceptualization of a field hydrogeologic framework that facilitates the development of analytical field testing procedures. The results of the test(s) may force changes in the initial conceptual model. Conductivity, hydraulic. Replaces the term "field coefficient of permeability." The volume of water at the existing kinematic viscosity that will move in unit time under a unit hydraulic gradient through a unit area measured at right angles to the direction of flow, if the porous medium is isotropic and the fluid homogeneous. Confining bed. A body of "impermeable" material stratigraphically adjacent to one or more aquifers; its hydraulic conductivity may range from nearly zero to some value distinctly lower than that of the aquifer. Flow, steady. Any point where the magnitude and direction of the specific discharge are constant in time. Flow, uniform. At every point the specific discharge has the same magnitude and direction. Flow, unsteady. At any point the magnitude or direction of the specific discharge changes with time. Fluid potential. The mechanical energy per unit mass of a fluid at any given point in space and time with respect to an arbitrary state and datum; the fluid potential is proportional to the head. Ground water, confined. Ground water under pressure significantly greater than atmospheric; its upper limit is the bottom of a bed of distinctly lower hydraulic conductivity than that of the material in which the confined water occurs. Ground water, perched. Unconfined ground water separated from an underlying body of ground water by an unsaturated zone. Ground water, unconfined. Water in an aquifer that has a water table. Head, static. Height above a standard datum of the surface of a column of water (or other liquid) that can be supported by the static pressure at a given point. Homogeneity. Hydrogeologic properties are identical everywhere. Hydraulic gradient. Change in static head per unit of distance in a given direction. Hydrostratigraphic unit. A body of material having considerable lateral extent and comprising a geologic framework for a reasonably distinct hydrogeologic system. Isotropy. Condition in which all significant properties are independent of direction. Porosity. Property of containing interstices or voids; may be expressed quantitatively as the ratio of the volume of its interstices to its total volume. Porosity, effective. Interconnected pore space available for fluid transmission; expressed as a percentage of the total volume occupied by the interconnecting interstices. Potentiometric surface. A surface that represents the static head along a particular specified surface or stratum. Specific retention. Ratio of the volume of water that the rock or soil, after being saturated, will retain against the pull of gravity to the volume of the rock or soil. Specific yield. Ratio of the volume of water that the rock or soil, after being saturated, will yield by gravity to the volume of the rock or soil. Storage, specific. The volume of water released from or taken into storage per unit volume of the porous medium per unit change in head.

Jan 1, 1986

By G. Markopoulos

Every year thousands of people from all over the world come to Mount Parnasse, visiting Delphi, the Parnasse ski-resort and other sights in the area of Fokida, available to all ages all year round. This region of Greece, is not only gifted with natural beauty, but also with valuable underground natural wealth: inside Mount Parnasse and the adjoining Ghiona Mountain, there are rich bauxite deposits - the ore from which aluminium is made. In this magnificent part of our country, any mining activities undertaken must be adapted to coexist within such an ecologically sensitive area. This demands an enormous effort, knowledge and the use of technology. This is definitely our Company's primary objective. Our company's (Silver & Baryte Ores Mining Co. S.A.) activities in the area began in 1933, when Euripides Mavrommatis and the two Eliopoulos brothers, Elias and George, established "Bauxite Parnasse SA". Since then, ten thousand people have worked in these ore deposits, and 45 million tons of bauxite have been extracted. The full length of the underground excavations is more than 300 kilometers and 115 million cubic meters of limestone have been extracted on surface mining. In 1996, Bauxite Parnasse merged with Silver & Baryte Ores Mining Co. S.A. Now, the company exports more than 1.500.000 mt per year of bauxite to more than 15 countries around the world, offers a significant amount of job opportunities in the region, and imports valuable exchange into the country.

Jan 1, 2002

By P. G. Semple, K. W. Major, R. M. Nendick

As free milling oxide gold ore reserves are depleted, more mining companies are having to evaluate the available alternatives for treating refractory deposits. The selection of a treatment process can be very difficult; and, despite the claims of their respective proponents, there is no one process that will continuously prove superior. Selection of the optimum process for an individual deposit is contingent on the size of the deposit, the grade of the deposit and the refractory nature of the ore. Since extensive metallurgical test programs are usually required to determine the optimum extraction process, an inappropriate initial selection may prove costly and time consuming. This paper discusses the steps involved in evaluating a refractory ore in order to expedite the evaluation of the required process through the feasibility study stage.

Jan 1, 1990