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By G. Bylapudi, A. Spearing, J. Weber, K. Mondal

U.S. National Institute for Occupational Safety and Health (NIOSH) reports state that about 100 million rock anchors are installed annually in U.S. coal mines (Tadolini et al., 2006), and rock-related safety remains an issue. The majority of these coal mines have conditions that make corrosion probable in the longer term. Despite this, very little research has been performed to analyze corrosion and its effects on rock anchors in coal mines. To further evaluate the effects of corrosive conditions in coal mines on rock anchors, three different experiments were conducted during an initial Illinois Clean Coal Institute (ICCI)-funded project from 2008-2009. The results of these experiments were further studied, with additional tests, in the extended ICCI-funded project during 2011-2012. The experiments were destructive testing, electrochemical testing (potentiodynamic polarization tests) and open circuit potential (OCP) testing, conducted in order to study corrosion in environments similar to those found in Illinois coal mines with a focus on major rock anchor types typically installed underground. Destructive test results showed highest reduction in peak strength at higher pH and temperature. From the destructive test results, epoxy-coated and galvanized anchors were observed to be better when compared to uncoated. Electrochemical testing was performed to find the corrosion potential and corrosion rates of ASTM A615 steel grades 40, 60 and 75 in four different solutions of varying sulfur content at ambient temperature. The effect of temperature and pH levels on corrosion potential and corrosion rates of steel grades were also evaluated with additional electrochemical testing, where an increase in temperature with all other constant conditions caused a significant increase in the corrosion penetration rate. OCP data indicated higher corrosion potential values (-mV) for rock anchors in wet areas, when compared to those from the dry areas. OCP test results of the rock anchors from the laboratory corrosion chambers were similar to those measured in the sampled coal mines.

Jan 1, 2013

By H. M. Woodrooffe

In the U.S.S.R. three of the world's major-known phosphate deposits are located. These have an estimated reserve of 2,600 million short tons of contained phosphorus. The best known lies in the "Khibiny Massif', an alkalaic rock formation some 600 square miles in area with mountain peaks rising to an altitude of 3300 ft above the surrounding terrain. Location and Climate The Khibiny Massif lies north of the Arctic Circle in the Kola Penin-sula, 100 miles south southeast of Murmansk, at a latitude of 67° 30' north and a longitude of 35° 30' east. It is serviced by rail from Murmansk and Leningrad (900 rail miles south). Figure 1. The phosphate operations are centered about the two cities of Apatity and Kirovsk. The former has a population of 35,000 and is on the Leningrad¬Murmansk railway. Kirovsk, 15 miles to the east, is now a city of 85,000. The region is at the limit of the tree line with most of the ground cover typical tundra. The mean annual temperature is -4°C and, in a normal year, precipitation occurs on 240 days. Because the temperature does not exceed freezing for 300 days each year, virtually all of the precipitation is snow. The two towns are nestled between mountains and, because of the weather, extensive avalanche control systems incorporating major engineering construction have been introduced to divert snow slides away from the populated areas. General Kirovsk was first settled in 1923 and the apatite occurrences were recognized shortly after. In 1933, the first concentrator for the recovery of the mineral was completed, producing in its first year of operation 170,000 tons of concentrate. With the growth and demand for phosphate in the U.S.S.R., a second concentrator was erected at Apatity. It calve on stream in 1963. Because of the severe climate, in the early days mining was limited to 85 days per year. With the introduction of new techniques and improved mining methods, the season has been extended to 115 days.

Jan 1, 1972

By James S. Browning

The principal uses of fine ground mica are as filler in wallboard joint cement, as a filler and surface coating for roofing, as an ingredient in paints, and in oil well drilling mud. The mineral has other uses in the manufacture of rubber, wallpaper, plastics, welding rods, electric insulation, house insulation, and textiles, and as an annealing agent in metal treatment. In recent years, more than 999 percent of the domestic mica produced has been scrap and flake mica (mica which does not meet specifications for sheet mica and is used for producing fine ground mica). There has been a continued increase in mica production for, several years, the 1963 production of scrap and flake mica totaling 117,251 tons.

Jan 1, 1966

By J. E. Gray

Before specifications are discussed it may be well to define the term "Mineral Aggregates." Professor K. B. Woods (1) defined "Mineral Aggregate--An aggregation of sand, gravel, crushed stone, slag, or other material of mineral composition used in combination with a binding medium to form bituminous and portland cement concrete, macadam, mastic, mortar, plaster, etc., or alone as in railroad ballast, filter beds, and various manufacturing processes, such as fluxing, etc. " This definition is too all inclusive for the purposes of this paper; therefore, this discussion will be confined to specifications for natural aggregates which means sand and gravel and crushed stone, and limited primarily to coarse aggregate which is aggregate larger than one-quarter inch in size. To the uninitiated, this may seem to be a very limited subject on an unimportant material. However, aggregates are essential in all types of construction. The tonnage and value of these two aggregates produced in the United States during 1959 as reported by the Bureau of Mines were as follows: Sand and Gravel 729,895,000 tons valued at $728,527,000 Crushed stone 581,721,000 tons valued at $824,411,000

Jan 1, 1961

By T. J. Batchler, K. M. Mohamed, D. F. Gearhart, R. K. Zipf

Seals are explosion-resistant structures built in underground coal mines to isolate abandoned mining areas from the active workings. An equivalent single degree of freedom (SDOF) method such as the single-degree-of-freedom blast effects design spreadsheet (SBEDS) developed by the U.S. Army Corps of Engineers can be used to design seals to resist mine explosions. The critical input for the SDOF code is the seal resistance function. The objective for this study is to develop engineering data for design of plain concrete (PC) and reinforced concrete (RC) seals using finite element (FE) models. The FE models can then be used to generate resistance functions for different PC and RC seal designs, which can be used in the SDOF codes. The U.S. National Institute for Occupational Safety and Health (NIOSH) researchers designed and built a test fixture for use in conjunction with NIOSH’s Mine Roof Simulator to apply a four-point bending load on the face of the tested seal. Eight large-scale experiments for each PC and RC seal were conducted. The experimental design considered the effects of the foundation strength, hitching and roof-to-floor convergence. Calibrated FE models for PC and RC seals were developed using ANSYS Ver. 13. With a very limited number of engineering-based assumptions and a single set of data—including Young’s modulus, compressive strength, stress-strain relationships, etc.—the PC and RC seal models successfully calculated the recorded resistance functions and failure patterns for a wide range of boundary conditions. Plug and RC seals were assumed for a 1.83-m- (6-ft-) high entry to demonstrate the application of the calibrated finite element models for calculating the resistance functions of these seals. The resistance function of a particular plug seal case was found to be a bilinear relationship. The resistance function of a particular RC seal without shear reinforcement was found to be a nonlinear relationship.

Jan 1, 2013

By Lorraine B. Burgin

The extensive lead time to develop most Arizona copper deposits commenced with initial production efforts before the turn of the century, when the first attempts were made to recover gold and silver and later copper from the high-grade vein deposits of the territory. Each of these discoveries, prospects, and early operations had its own lead time and life cycle as economic production was attempted. Because prices of the metals fluctuated and the higher grade material was depleted, economics forced operations to close and companies to fail. Renewed interest in the property because of improved conditions, different interpretation of the geologic structure, or new promotional ability frequently resulted in the formation of yet another company to finance the exploration and, hopefully, the development of the property. This cycle of renewed activity and subsequent abandonment was and is common, accounting for many lead times and for the long period of time from the initial location of claims to large-scale production. In order to gain a perspective on the lead-time interval necessary to achieve development of a large-scale operation, the histories of several major Arizona mines were examined, rather than a simple listing of discovery and production dates of many mines to arrive at a statistical average. The Miami, Castle Dome, Copper Cities, San Manuel, and Twin Buttes properties were studied, and as much data as possible obtained on the Pinto Valley, Esperanza, Sierrita, Pima, and Mineral Park-Ithaca Peak properties.

Jan 1, 1974

By D. Pappas

Over the past decade, the number of contractors working in underground coal mines has nearly doubled; however, the effect this has had on the industry's injury rates has been the subject of much speculation. The confusion exists because the U.S. Mine Safety and Health Administration (MSHA) database does not assign contractor hours to the individual mining operations where they worked. To better understand the safety record of the contractor segment of the industry, the National Institute for Occupational Safety and Health (NIOSH) undertook a comprehensive analysis of the data contained in the MSHA database. The first part of the study compared overall contractor and operator trends from 1983 to 2009 related to employment, hours worked and injury rate. One unexpected finding was that the larger contractors tended to have higher injury rates than the smaller ones. The second part of the study directly addressed the role of contractors on the safety record of 10 large underground coal mines. A detailed analysis provided both injuries and estimated contractor hours worked at these mines for the period 1992-2007. Comparison between the estimated contractor injury rates and the reported operator injury rates at these mines indicated that the contractor injury rates were significantly higher at most of the operations studied. However, the industry-wide data indicates that contractor and operator injury rates have converged since 2005 and are now equivalent. Mining Engineering, 2011, Vol. 63, No. 11, pp. 73-79. Official publication of the Society for Mining, Metallurgy and Exploration, Inc.

Jan 1, 2011

By Richard H. Sillitoe

Gold is an important byproduct and, locally, coproduct of porphyry copper deposits, and possesses potential for discovery as the major metal in porphyry deposits in either island arcs or Cordilleran belts. Tungsten and tin occur as major components of several potentially bulk-minable porphyry deposits, as well as being byproducts from the Climax porphyry molybdenum deposit. Whereas porphyry tin systems are localized in Cordilleran back-arc settings, their tungsten counterparts appear to span a range of geotectonic settings, from Cordilleran principal arcs through back-arcs to rifts. Although silver is a common byproduct of porphyry copper deposits, it tends to be preferentially concentrated with lead and zinc on the fringes of all types of porphyry deposits and/or as late-stage superpositions; the latter situation could be of some interest in the higher parts of porphyry systems. As byproducts, rhenium, uranium, platinoids and magnetite are exploited occasionally, and rutile and the rare metals, such as tantalum and niobium, have merited consideration.

Jan 1, 1982

It had been more than a decade since this many booths were occupied at an SME Annual Meeting, but at the 2010 meeting in Phoenix, AZ 630 booths were sold to 470 vendors from the entire spectrum of the mining and minerals industry. Exhibitors such as Metso, FLSmidth, West-Tech, ABB, NIOSH, Eriez and Resource West took their usual prominent places on the exhibit floor and were joined by newcomers such as tunnel boring machine manufacturer Herrenknecht AG, Frontier Kemper, the International Society of Explosive Engineers and more than 100 other first-time exhibitors. On the floor, one could find everything from a new pair of boots to a new career in the recruitment pavilion where some of the biggest companies in mining (Barrick Gold, Freeport-McMoRan, Newmont Mining, etc..) set up shop. The following is a look at some of the companies and products that were on display at the 2010 meeting. For information about displaying at the 2011 annual meeting in Denver, CO, Feb. 27 to March 2, contact exhibits@smenet.org.

May 1, 2010

By J. Noll, A. Miller, J. Volkwein, C. Pritchard

Hecla Limited, Magee Scientific and the U.S. National Institute for Occupational Safety and Health (NIOSH) combined efforts to evaluate an in situ air filtration system for use in an underground mine environment. The purpose of the collaboration was to determine the efficacy of such a technology for reducing the concentration of airborne diesel particulate matter (DPM), with the aim of improving air quality in underground hardrock mines. A secondary goal was to evaluate the use of an aethalometer as a means of real-time measurement of black carbon as a surrogate for DPM. The evaluation included measuring the DPM-capture efficiency of the filter when it was preloaded with dust. Toward this end, rock dust was introduced at the filter inlet to create a dust layer on the filter surface, with the intent of providing improved capture of the much smaller DPM particles. The filtration efficiency for DPM was assessed by comparing measurements of DPM taken at the inlet and outlet of the system, using both realtime and time-weighted-average approaches. The real-time measurements were performed with a Model AE33 aethalometer, and filter samples analyzed by the NIOSH 5040 method were used to assess the effects of the system on time-weighted-average concentrations of total carbon. Results showed a reduction in DPM concentrations in the range of 82 to 89 percent. While the calculated efficiencies based on the two different measurement methods were similar, the DPM levels reported by the aethalometer were higher, possibly due to differences in the performance of the size selectors used for the two methods: impactors versus cyclones. More research is required to develop a robust correlation between the two methods to support the use of the aethalometer in future mining applications. The advantages of the aethalometer are that it can measure and record DPM levels for weeks at a time and can be directly connected to a mine monitoring system, potentially at multiple locations. Ideally, such data can be used to initiate the startup of the filtration system should DPM concentrations reach an action level. This work demonstrated that in situ filtration systems, modified to collect DPM and coupled with real-time monitoring, show promise in reducing DPM concentrations in the mine environment.

Mar 1, 2017

By J. D. McAuliffe

The Homer-Wauseca Mine is operated by the Hanna Mining Company, three miles north of Iron River, Michigan on the Menominee Iron Range. The mine produces 5,300 tons of direct shipping iron ore daily. The present main producing level is at a depth of 1,500 feet below the collar. The ore body continues to a depth of 2,700 feet below the collar, to which depth the modern circular concrete shaft has been completed. A view of the property is shown in Figure #1. This paper is a report on the development of large underground boreholes used initially to conduct stope filling material into inaccessible, mined-out stopes. Later holes were drilled for ventilation raises, for mine drainage, for passageway for power cable, also for the primary breaking point for long hole stoping. Some, which were drilled as ventilation raises, were later stripped to a suitable size for a manway or ladder road. The holes varied in size from 6" to 30" with the present popular, economical working size being 16 1/4", used as a stope fill passage in mined out areas and for ventilation in deeper development. Foremost has been the desire to develop equipment suitable for drilling raises large enough for manways.

Jan 1, 1963

By Betty L. Gibbs

Microcomputers are becoming more convenient to use at all levels of the business world, including the mining industry and mine offices. The state of the mining industry requires that we become more productive and innovative in our analysis of deposits and operations. With the help of computers, examination of options to increase productivity can be performed quickly and inexpensively. Effective use of the computer for designing underground workings combines the calculation power and speed of a computer with the technical expertise and judgment of the engineer. Computer programs can perform calculations in minutes that could take an engineer several months. The engineer must be on guard when using the computer for any calculation because it is very easy to assume the results produced by a computer program are always correct. The computer is a sophisticated calculator but cannot recognize logical errors nor transposition of numbers. Also some intuitive or obvious decisions made by an engineer are difficult or impossible to program effectively.

Jan 1, 1987

Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problems a population balance model based on first principles has been developed for fine particle flotation in a column. Two different terms have been considered in the model, i.e., transport and rate. Transport terms, incorporating fluid flow and bouyancy, are used to describe the movement of air bubbles, unattached particles and bubble-particle aggregates along the length of the column. Rate terms, which describe the bubble-particle attachment process, have been derived from first principle considerations. Because the model is based on first principles, it can be useful for the design, control, optimization and scale-up of column flotation cells.

Jan 1, 1987

By A. Juganda, Jr. Bogin, S. Saki, R. Gilmore, J. Brune, J. Grubb, S. Lolon

"In longwall mines, atmospheric or barometric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area of the mine, resulting in a phenomenon known as “gob breathing”. Gob breathing triggers a gas flow across the gob and the working areas and may result in a condition where a methane accumulation in the gob flows into the face area forming an explosive mixtures. This paper discusses results of Computational Fluid Dynamics (CFD) modeling carried out to analyze this phenomenon and its impact on the explosive mixture development under a bleeder-ventilated longwall gob panel scheme. Modeling results indicate that the gas inflow and outflow across the gob and the formation of Explosive Gas Zones (EGZs) are directly affected by the barometric pressure changes. Methane gas and EGZs in the gob expand out toward the face and bleeder entries during the falling barometric pressure. Where methane zones interface with mine air, EGZ fringes may form along the face and in the bleeder entries. When the atmospheric pressure increases, an ingression of oxygen into the gob is observed that can also increase EGZs in volume. The findings from this study help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures. INTRODUCTION Methane explosions continue to be a daunting risk for underground coal miners, although the number of related fatalities and injuries in the U.S. coal mining industry has steadily decreased since the establishment of the U.S. Bureau of Mines in 1910. Still, the consequences of a methane explosion are often disastrous with multiple fatalities and property damage often leading to permanent shutdown of the mine. Methane is formed during the coalification process and is released from the coal seam to the mine atmosphere when the coalbed is disturbed by mining or natural causes such as earthquakes. If not properly diluted by appropriate mine ventilation, this methane may accumulate in the active mine workings and gob areas. Researchers at the Colorado School of Mines have developed numerical models showing how and where explosive methane may accumulate in gob areas. Historical mine explosions appear to show a connection between mine explosions and fluctuating barometric pressure as a result of stormy weather. McIntosh (1957), Boyer (1964), and Kissell et al. (1973) studied the influence of barometric drops on major coal mine disasters in the United States prior to 1970. Their statistical analyses found that a majority of these disasters occurred in the fall and winter months when the barometric pressures were influenced by unstable weather conditions and noted increased methane content in the mine workings during times of falling pressure. Studies conducted by Fauconnier (1992) and Hemp (1994) found similar connections between methane explosions and barometric pressure fluctuations in a majority of gas explosions in South African mines. Ten out of twelve major mine explosions with five or more fatalities in the U.S. after 1970 were found to have occurred during the months of November through April when barometric pressure swings were more abrupt and intense (Lolon et al., 2015)."

Jan 1, 2016

By Henry T. Miller

INTRODUCTION The basic purpose of this paper is to suggest procedures and practices to insure that no employee working in a uranium milling operation receives exposure to radioactive, toxic, or other materials or agents that might produce a permanent, deleterious effect upon his physical health and well-being. This program is also designed to insure that each employee can carry out his assigned duties without risk to his health or to that of his fellow workers. The assumptions underlying this program are by necessity, conservative, with emphasis being placed upon prevention rather than correction or reaction to an undesirable situation. The limits specified-either as Threshold Limit Values (TLVs), Maximum Permissible Concentrations (MPCs), or Radiation Protection Guides (RPGs)--represent both standards of best practice and those of law and regulation. The total program is envisioned as a balanced combination of occupational hygiene and radiation monitoring. This includes surveying, air sampling, personnel dosimetry, bioassay, medical surveillance, epidemiology, and training--all backed by a thoroughly tested and evaluated set of emergency procedures. The program, as presented, is keyed to the results of monitoring, surveying, air sampling, medical surveillance, and epidemiology--it being obvious that no problem can result when no hazard can be identified. The lack of an identified hazard, however, does not negate the need for such a program and prudence suggests the need for routine surveillance programs in the best-designed facility. [The Model Mill] The model mill used in this paper is that presented by the U. S. Environmental Protection Agency in its study of the uranium fuel cycle1. The model mill processes 600,000 metric tons of ore per year into 1,140 metric tons of U308 as yellowcake per year using an acid leach process. Other characteristics of the mill such as location, tailings dam design, number of light water reactors supported, and geographical location are not pertinent to this paper. The usual remote western location of these facilities produce some difficulties in delivering the required occupational medical services and is not within the scope of this paper. The operating lifetime of most mills is commonly estimated as from 12 to 15 years in actual practice; however, the U. S. Environmental Protection Agency estimated a 20-year lifetime for its model. The principal steps in the acid leach process include :2 (a) Ore is blended and crushed to pass through a 2.5 cm (one inch) screen. The crushed ore is then wet ground in a rod or ball mill and is transferred as a slurry to leaching tanks. (b) The ore is contacted with sulfuric acid solution and an oxidizing reagent to leach uranium from the ore. The product liquor is pumped to the solvent-extraction circuit while the washed residues (tailings) are sent to the tailings pond or pile. (c) Solvent extraction is used to purify and concentrate the uranium. (d) The uranium is precipitated with ammonia and transferred as a slurry. (e) Thickening and centrifuging are used to separate the uranium concentrate from residual liquids. (f) The concentrate is calcined and pulverized. (g) The concentrate or yellowcake is packaged in 208 liter drums for shipment. This process is illustrated in Figure 1.3

Jan 1, 1981

By Michael G. Nelson, Amy Richins, Ashley Hodgson, W. Pratt Rogers

"Sociotechnical systems are everywhere in the modern industrial world. Sociotechnical systems describe how humans interact with technology throughout a variety of processes. These systems are prevalent in modern industrial settings, such as operating mines. Safety and health management systems (SHMSs) are complex sociotechnical structures designed with the aim of managing and reducing occupational risk. U.S. mining companies are voluntarily adopting SHMSs to supplement regulatory safety compliance efforts. Like all complex sociotechnical systems there are a wide variety of approaches and adoption philosophies around a SHMS. Many SHMSs suffer from high levels of redundancies, which manifest themselves in diverse ways: duplicate processes, forms, permits, and tracking mechanisms. These redundancies have severe impacts on the overall system and absorb critical culture and leadership “energy”. A recent study initiated by the University of Utah and sponsored by the Alpha Foundation is investigating the effectiveness of SHMSs across 15 different U.S. mining sites. A large amount of data has been captured to help characterize elements of SHMSs and correlate their impacts on safety outcomes. Many variables were assessed in the study. Those of importance to this paper are the variables describing the robustness of the sociotechnical aspects of the SHMS. Two such variables are the overall integration of the SHMS within the whole system and how data is managed. Data management in this context deals with the approach to capturing, analyzing, and acting on data within the system. As well, systems are integrated around controlled, data-sharing mechanisms. It has been found that wide variety of approaches has been taken to integrate the SHMS within the governing management philosophy at a given site. A series of case studies is presented that develop some specific best practices for proper data management and integration of SHMSs.Introduction and Project Background Managing occupational health and safety can be done in many different ways, and with many different approaches, but is often based on the host country’s regulatory and industrial culture. However, many companies have extended their effort beyond the regulatory requirements of their host nation and have implemented Safety and Health Management Systems. The goal of these efforts is to reduce and eliminate occupational risk. Many health and safety practitioners have a hard time justifying various elements of health and safety management. There is a lack of institutional knowledge that measures and assesses the effectiveness of these Safety and Health Management System (SHMS) elements. To better understand the effectiveness of SHMSs the Alpha Foundation has funded a research project with the University of Utah. The title of the project is “Characterization and Effectiveness of Safety and Health Management Systems in the U.S. Mining Industry.” The research team will assess the SHMSs of 15 United States mine sites. The outcome of the project will be a method to characterize the strength of the SHMS elements, assess a culture and leadership index, and finally establish correlations between elemental risk and safety outcomes. The study is currently in progress. However, many important outcomes have already been observed, particularly on the data management practices within an SHMS."

Jan 1, 2017

By W. J. D. Stone

Many of the common valuable minerals have a magnetic susceptibility which is sufficiently high to render them amenable to magnetic separation. In addition,, many minerals which form the unwanted constituents of an ore can be removed by magnetic means. Magnetic separation in general has suffered seriously from, the lack of a high intensity wet separator. It is only recently that such a separator has become available to the industry. Prior to this, high intensity magnetic separation has been limited to the use of the dry techniques. Since the introduction of the Jones Wet High Intensity Magnetic Separator, extensive test work has been conducted to investigate possible applications. From the investigations conducted and the discussions that have taken place in the industry, it is apparent that the important mineral characteristic of magnetic susceptibility is not receiving the attention that it deserves. Applications for high intensity wet separation are being found in areas hitherto not considered.

Jan 1, 1963

Maptek, an international development software company, released version 3.2 of its Vulcan three-dimensional mining and geological software package. This latest release is expected to give clients better graphics performance and improved overall solutions. In addition, the company also released the NT version of Vulcan for Unix and personal computers. More than 800 code changes have gone into the 3.2 release, the Lakewood, CO-based company said. Many of these changes were in response to requests from Maptek's customers. Others have been motivated internally by the company to achieve better performance in its Envisage graphics interface. The introduction of hot keys and user-defined menus makes Envisage a more flexible interface and a more productive working environment. A new animation option provides new ways to enhance the organization and display of data. The animated data can include point, string, grid, triangulation and photographic-draped data. The shaft-mapping facility is also included in version 3.2. It enables the cylindrical view of the shaft to be unwrapped and displayed on the screen while the data remains in its true world coordinates. Major upgrades to Vulcan include underground blast design and geotechnical modules. The new blast design module allows the user to develop a ring design in any plane defined by the stope layout. Radial and offset holes can be developed. User-friendly editing tools make adjustments to the initial design a simple task. The user defines the plotting and reporting of rings and plot style templates allow flexibility in reporting. New features in the geotechnical toolbox include options to create daylight windows and pitch lines on the stereo nets. Geotechnical databases can be directly updated from the interpretation of the stereo net. Direct annotation of the symbols on the net is now possible and the stereo net display can be customized. Improvements to the documentation and links within the text have made the on-line help easier to navigate. Maptek also released the NT version of Vulcan soft- ware. The comprehensive design of the software pack- age for Unix and personal computers provides a three-dimensional geological modeling and mine planning system within a natural graphics environment. Users who require the power to manipulate extra- large and complex data sets will still be served by the Unix platform. Users who handle small-to-large datasets can now choose between Unix and personal computer platforms. The NT version will appeal primarily to companies that already have a personal computer network. Response to industry feedback was the basis for developing the NT version. "We want to ensure that our clients receive the optimal product for their needs," said Nicolas Simon, vice president of Maptek in North America. Some advantages of the NT version include: ? Most mining professionals are familiar with the personal computer platform. ? All of the familiar personal computer tools are now available to Vulcan users. ? Resource modeling tools that previously required the powerful Unix workstations have been brought into the personal computer environment. This will help mining companies save money. From a binary data point of view, the personal computer NT version is compatible with other platforms, such as SGIIDECIHPISUN, allowing integrated personal computer and Unix environments For more information, contact Cherie LeDoux, Maptek, 165 So. Union Blvd., Suite 777, Lakewood, CO 80228, fax 303-763-4921, e-mail: info@maptek.com, Internet: http:llwww.maptek.com.

Jan 1, 1997

By G. M. Wenberg

Bacterial leaching of copper and uranium is practiced in environments containing available sulfur and iron and having a strong acidic reaction. However, many mineral deposits do not have these conditions; the chalcocite and native copper ores in Michigan's Upper Peninsula are examples. Bacterial and fungal populations were observed in samples taken from the White Pine Copper Company tailing pond and mine, and isolates were prepared of the dominant species. The isolates were then screened for solubilization of copper from tailing, ore, and concentrate during incuba¬tion in a carbon and nitrogen supplying medium. Certain Penicillium fungi solubilized significant amounts of copper under neutral to slightly acidic conditions. Leaching apparently was accomplished by release into the medium of metabolites which chelated with the copper.- The process was found to be highly dependent upon the medium and the concentration of copper in the source material. The paper describes sampling and screening techniques, presents the results of experimentation to standardize procedures and maximize the yield of copper, and discusses the nature of the leaching process. This preliminary research reveals a biological process which may find use in mineral extractions but whether it can be applied economically remains to be determined.

Jan 1, 1969

By Ernest F. Giovannitti

A couple of years ago, one of the major television networks produced a series on the environment. One episode in the series dealt with the nation's solid waste problem and some of the research being done to solve it. It was interesting to listen to one researcher who was attempting to develop a glass that when broken would dissolve in water. It was said that using this glass would eliminate over 100 million tons of solid wastes each year. At first glance, it would appear that this research-effort would make a significant contribution to environmental pollution control; however, if one pauses to consider the water, he can see that this solution to the solid waste problem may well contribute to a water pollution problem. The dissolved material must either end up in our surface streams or be removed in waste treatment systems. Either alternative may have a more adverse effect on the environment than the original problem. With today's emphasis on the environment, it is important that the effects of our activities be studied in depth. Then, by properly planning the activity, the adverse effects can be minimized. The coal mining industry 100 years ago was in the same boat, as our glass maker, is today. Unfortunately, it too failed to consider all the effects of its activities and as a result, in Pennsylvania, there are over 5000 miles of streams adversely affected by coal mine drainage. The situation is improving, however, because mine operators are beginning to recognize and accept the methods for controlling coal mine drainage. The purpose of this paper is to discuss the measures for the control of coal mine drainage and to set forth the factors that affect these controls.

Jan 1, 1972