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By Wenming Wang, Edgar E. Vidal, Scott A. Shuey, Patrick R. Taylor, Judith C. Gomez

Introduction In modern society, vanadium is defined as a strategic metal. Some 90% of the global consumption is used as an alloying agent for carbon steels, tool steels, and high-strength low-alloy steels (particularly for pipelines). Advanced titanium-aluminum-vanadium alloys are seeing application in the aerospace industry. Small but ever growing amounts are finding application as catalysts or in electronics. New uses are continually being discovered for this metal. One example of a new application is the vanadium-redox battery for use in generation plants and back-up power sources. Vanadium is found in a large number of minerals, of which the most important are carnotite, roscoelite, vanadinite, mottramite, and patronite. Just over a third of the world's vanadium is produced as a primary product; the balance is a by-product of the iron and steel, oil refining, power generation and uranium enrichment industries. Vanadium can also be sourced by recycling spent catalysts from the petrochemical industry and ash produced by the combustion of oil emulsion in power stations. However, recycling activities are believed to account for only a small amount of total world supply. Vanadium is recovered from these ores largely as the pentoxide (V2O5) [1]. The major sources of vanadium-bearing magnetite ores are scattered throughout Australia, China, Russia, and South Africa. Current estimates of world’s Proven & Probable vanadium reserves are of the order of 41.3 million tones [2, 3]. Commercial vanadium-bearing titaniferous magnetite deposits can be found in Kachkanar, Russia; Pan Zhihua, China; Bushveld, South Africa; and Windimurra, Western Australia [4]. Other deposits have been found in New Zealand, Canada, and India, among other countries. Vanadium consumption in the steel sector has increased some 7% per ton of steel over the last 10 years as new alloying applications have been found to improve steel's strength-to-weight ratio. Future demand from the aerospace and nuclear industries for non-ferrous vanadium alloys such as titanium and super-alloys is also likely to grow. Vanadium is usually added in the form of ferrovanadium, a vanadium-iron alloy. Vanadium compounds, especially the pentoxide form, are used in the ceramics, glass, and dye industries, and are also important as catalysts in the chemical industry. While established approaches may be used at an industrial scale to treat vanadium-bearing titaniferous magnetite ores in several countries, new alternatives are being developed worldwide. This review will give short overview of the treatment of vanadium-bearing titaniferous magnetite ores, an overview of direct reduction and direct smelting processes and an approach to determine technical alternatives for the property.

Jan 1, 2005

By Rebecca S. Stanevich

BACKGROUND Diesel exhaust is an animal carcinogen, although evidence of the carcinogenicity in humans is "limited". (World Health Org. , 1989) Of the eight cohort studies in the 19808, five found an increased risk for lung cancer among workers who may have been exposed to diesel exhaust (RR from 1.3-1.5, SMR from 101-132). (Howe, et al., 1983) Only two studies accounted for smoking indirectly. Of the ten case-control studies in the 1980's, eight reported increased risk of lung cancer among those populations purportedly exposed to diesel exhaust. (Benhamou, et al. , 1988) All but one of these adjusted for smoking and other occupational exposures. The odds ratios ranged from 1.2 to 2.1. In two of these studies, miners experienced a two to three fold risk. (Benhamou, et al., 1988) Bladder cancer has also been linked to diesel exhaust in cohort and case-control studies. Excesses of approximately 50% were observed among truck drivers in studies by NCI. (Hoar, et al., 1985) In the National Bladder Cancer Study, risks for truck drivers rose with duration of employment. A study by NIOSH in Ohio also found an excess of bladder cancer among truck drivers, particularly among those with 20 or more years of employment. (Steenland, et al, 1987) Despite the large number of studies in which the relation between diesel exhaust exposure and lung cancer has been examined, exposure to diesel exhaust has been quantitatively estimated only in the studies of railroad workers and truck drivers. (Woskie, et al., 1988) The excess lung cancer risk experienced by workers in these two occupational groups was modest, ranging from 40 to 90% for those with long-term employment. However, diesel exhaust exposure among railroad workers and truck drivers is lower than that seen among miners. Several markers of diesel exhaust have been utilized in these studies. Diesel exhaust is a complex mixture of particulates, vapors and gases. One group of these gases, the nitrogen oxides, react with polynuclear aromatic hydrocarbons, forming mutagenic and possible carcinogenic nitrated derivatives. (World Health Organization, 1989) For this reason, and because it is easy to measure and analyze, NO, was frequently used as a marker of diesel exhaust exposure. As part of the Garshick (Garshick, et al., 1988) study of railroad workers, Woskie measured NO, exposures of 477 railroad workers. (Woskie, et al., 1988) Geometric mean exposures of 13 job groups ranged from 12 to 80 ppb. In a New Mexico potash mine, (Attfield, et al. , 1982) exposures of from 100 to 3300 ppb nitrogen dioxide

Jan 1, 1992

By Michael J. Martinson

Mine ventilation has been evolving as a separate field of study since the middle of the nineteenth century, and some practitioners might assert that mine ventilation has come of age as a discrete field in the last decade or two. Certainly the extensive literature now available on many facets of the subject, international congresses, the phenomenal upsurge of interest in mine ventilation in the United States of America since the passage of the 1969 Federal Coal Mine Health and Safety Act, and the existence of a virile mine ventilation society in South Africa with its own monthly journal all point in this general direction; on the other hand the lack of a rational design philosophy for ventilating mines suggests that mine ventilation may still be on the threshold of maturity. To generalise, many mines are still ventilated simply to comply with arbitrary statutory regulations, or with some ill- defined notion of reducing the risk of injury associated with the atmospheric environment in mines. Hazards in this category include oxygen deficiency, toxic gases and particulates, pathogenic gases and aerosols, explosive gases and dusts, and extreme climatic conditions. Although many mines are ventilated to abate the risk of a specific injury, there is inevitably a spectrum of latent and patent atmospheric hazards in every underground mine. The writer (Martinson, 1976) has previously drawn attention to the dearth of material on mine ventilation design in textbooks and technical journals, and to the overly simplistic approach sometimes adopted in the limited work published on the subject. The available material undoubtedly contains useful technical data and persuasive views, but seemingly could not be used to demonstrate the rational engineering approach to mine ventilation design advocated in the present paper. The range of papers presented at the 1975 and 1979 Congresses, and the diverse interests and affiliations of delegates, emphasize the multidisciplinary nature of mine ventilation. Easily recognisable topics include: Fluid mechanics Thermodynamics Heat transfer Flames and combustion Aerosol physics Radiation physics Geophysics and geomechanics Occupational diseases Epidemiology Industrial physiology Despite these heterogeneous connections there can be little doubt that mine ventilation is fundamentally an engineering field and not an off-shoot of some other branch of applied science. The distinction is important because mine ventilation has essentially developed as a form of ad hoc trouble- shooting, and in the process mining engineers have relied extensively on the assistance of experts drawn from other fields. Thus historically there has been limited scope for the application of rational design techniques, and personnel enlisted from scientific disciplines may not have had any previous experience in the intricacies of engineering design.

Jan 1, 1980

By Sheldon P. Wimpfen

SHELDON P. WIMPFEN The measure of the success of any mining operation is the size of the difference between sales realization and cost of product, including operating, sales, administra¬tive, capital and others. Evaluation of a mining project necessitates projecting costs and sales realization as accurately as possible. Possible variations in specific cost elements and sales prices must be considered. To accomplish this, project studies should include giving effect to possible fluctuations to determine the break¬even points with varying costs and prices. Development of cost data is never an easy task. Mining is characterized by a great variety of conditions which result in still more variables. Achieving realistic figures as of any specific time involves consideration of changes, which may be frequent, in labor-contract terms and equipment used, variations in working condi¬tions and mining practices, and changes in mineralization and metallurgy. The purchasing power of the dollar, which has been declining persistently, also affects the situation at any given time. The only thing that can be said of costs, with certainty, is that they will change. With this in mind, the "guideline" data in this section are offered for the use of the mining engineer. It was provided for the most part by representative companies, whose contributions are gratefully acknowledged. In reviewing the tabu¬lations and other material it is of course necessary to remember that the data presented are valid only for the time periods specified, and will change with changing economic conditions in any other. 31.1-CAPITAL COST OF PLANTS Plant capital costs are set forth in Tables 31-6 and 31-7 by year of construction. To estimate capital cost of plants built in future years, various cost bases and indexes are utilized. Design and Construction Manpower: Monthly Salary Ranges, January, 1970 Project manager $1,400-82,600 Project engineer1,000- 1,500 Project design engineer1,050- 1,800 Senior engineer1,000- 1,700 Senior design engineer1,100- 1,700 Senior engineering designer1,000- 1,300 Layout draftsman750- 1,000 Detail draftsman650- 1,000 Material engineer900- 1,400 Construction-project manager1,500- 2,500 Project engineer1,500- 2,500 Construction superintendent 1,500- 2,500 A rule of thumb in design work is one man-month per drawing. The number will vary for each specific plant. For a recently constructed 30,000-tpd (tons per day) copper concentrator, 1,800 drawings were made. Design should provide for the addition of milling units when these may become justified in relation to investment markets and life of the deposit.

Jan 1, 1973

By Bo-Hyun Kim, Mark K. Larson

"Researchers at the National Institute for Occupational Safety and Health (NIOSH) have advocated the use of instrumentation in underground mine ground control studies to aid in understanding failure mechanisms and to calibrate numerical models. The purpose of these efforts is to reduce accidents and fatalities in underground mines resulting from inadequate design of mining layout or supports. A recent examination of some results of stress change measurement raised some questions about the validity of elastic solutions in ground, such as coal. Particularly under deep cover as is prevalent in the western United States, the coal around a borehole would likely have yielded so that post-yield behavior would govern the response of the instrument.A numerical experiment was conducted by NIOSH researchers using the FLAC software (Itasca Consulting Group, 2016) to investigate the response of the borehole pressure cell (BPC) and the biaxial stressmeter to varying degrees of plastic behavior. The pre-encapsulated BPC cell pressure exhibits increasing departure from the elastic case with decreasing post-peak-strength slope of the stress-strain curve. On the other hand, because the BSM usually provides much more confinement to the surrounding rock than does the BPC, the measurements obtained from the BSM do not depart significantly from the changes in secondary principal stresses and directions as calculated by the elastic solution.INTRODUCTIONSeveral years ago, Larson et al. (2000) described several instruments that NIOSH had used in underground field studies and how to monitor them with dataloggers. This information is still relevant because of the need to understand how excavation affects the stability of mines and thus, the safety of mining personnel. One class of instruments described in that paper includes those instruments that measure change in rock stress. Although several such instruments might be used to measure stress change, the focus of this paper is on two instruments with which NIOSH has had more recent experience—the borehole pressure cell (BPC) (Geokon, 2018a; RST Instruments, 2018) and the biaxial stressmeter (BSM) (Geokon, 2018b). Other instruments, such as the CSIRO hollow inclusion stress cell (HICell) (Earth Sciences, 2019; Worotnicki and Walton, 1976) may be included in future studies.Early studies in the development of the BPC were those of Panek and Stock (USBM, 1964), Sellers (1970), Lu (1984), and Babcock (1986). Babcock’s work is particularly useful, but his setting and testing range was far below what we experienced in the NIOSH study, and it was Babcock’s data reduction scheme from his laboratory experiments that was used to calculate stress change in the NIOSH study (NIOSH, 2019a)."

Jan 1, 2019

Global mining company achieves significant productivity gains with three-dimensional (3D) mine models developed with Abaqus finite element analysis software. In a steep change beyond traditional processes, Abaqus finite element analysis (FEA) software from Simulia (the Dassault Systèmes? brand for realistic simulation), is being used to enhance mine design and engineering simulation at a number of major mines around the world. In North and South America, Africa and Australia some of the world?s biggest mining companies are applying FEA technology to evaluate safety and improve design planning, implementation and operations. Beck Arndt Engineering (BAE), a Sydney-based international consultancy, is a pioneer in the commercial development of engineering solutions for the mining industry. The consultancy has worked closely with engineers at Simulia Australia to expand the use of Abaqus FEA simulation software for mining applications. Among the early adoptors of mine-ready FEA technology is the world?s largest miner, BHP Billiton. With BAE?s help, BHP has already applied this technology to evaluate mines in Canada and Australia. At the BHP Billiton Nickel West Perserverance Deeps Project in Western Australia, Abaqus FEA software is now being used to help engineer the safety and productivity of planned deep-mining operations. To achieve this goal in the deep-mining environment significant technological innovation is required. Using measurements of site deformation and seismicity, Abaqus FEA models have been calibrated and, in a single day, used to simulate a full, 3D, inelastic analysis of a mine?s life cycle. In recent years, similar applications at Debswana?s Jwaneng Mine in Botswana, the Newcrest Mining Ridge-way Deeps Project in New South Wales, Australia and Rio Tinto?s Argyle Diamond mine in Western Australia have also established Abaqus FEA analysis as the lead-ing technology for multi scale, simulation-aided mining engineering. Joop Nagtegaal, a pioneer of FEA and a Dassault Systèmes Corporate Fellow, said that Abaqus FEA software is unique in its capabilities to enable mining engineers to investigate design innovations from the drawing board to full production. ?In the design stage, Abaqus models, which include rockmass volumes spanning several kilo-meters around the ore body and down to excavations just a few meters across, are used to compare and optimize engineering options,? Nagtegaal said. ?Then, as the mine goes into production, large volumes of data from the field are incorporated with the analysis models to allow them to be calibrated to a precision not previously available to the mining industry.?

Jan 1, 2009

By K. V. Raj, VASU GANGRADE

Airflow in large-opening stone mines is largely dependent on the natural ventilation due to the large cross- section area of the opening. The openings of such stone mines are typically twice or thrice the size of typical underground coal or metal/nonmetal mines. Due to the influence of natural ventilation, air velocities as well as the static pressure drop in the mines are low. Mines rely on auxiliary fans to ventilate active faces to reduce contaminant exposure to mine workers. The National Institute for Occupational Safety and Health (NIOSH) is conducting research on ventilation of large-opening stone mines to reduce worker exposure to dust and other contaminants such as diesel particulate matter (DPM). In order to reduce worker exposure to dust and DPM, an understanding of the airflow pattern due to auxiliary fans in the mine is needed. Under this research, NIOSH researchers are exploring the computational fluid dynamics (CFD) modeling to understand the airflow behavior in large-opening mines. In this paper, the team is presenting the results from three-dimensional CFD modeling of airflow in a large-opening stone mine and investigating the effect of a fan placement with the movement of trucks.

Feb 1, 2025

By J. K. Whyatt

In situ stress on the scale of a tunnel or mine may be distorted by geologic structures. The resulting variations of in situ stress have a direct bearing on the potential for mining-induced seismicity. New evidence from the Lucky Friday Mine collected by U.S. Bureau of Mines researchers, as well as a review of case studies, demonstrates that in situ stress variations affect the spatial distribution of mining-induced seismicity. Although overcore stress measurements have been useful in these studies, they are too expensive and, depending on conditions, may be too difficult, to use routinely in mapping stress variations. However, information from borehole and raisebore breakouts; deformation of mine openings; and patterns of seismicity, ground control problems, and rock burst damage can be used to build a stress database. This database can then be used in con-junction with maps of mine structure and geology and models of rock mass behavior to build a map of in situ stress variations. Such a map provides a means to anticipate patterns of mining-induced seismicity that are likely to be encountered and, hence, provide a means for planning appropriate measures to ameliorate rock-burst hazards.

Jan 1, 1995

By Morgan M. Sears, Gamal Rashed, Michael M. Murphy, Brent Slaker

In this study, a parametric study was conducted using FLAC3D numerical models to examine the impact of oblique loading, generated from seam dip, on the strength and the failure propagation pattern of a stone pillar using two simplified geometry types. In type 1, the sidewalls of the pillars were assumed to be perpendicular to the roof and the floor, while in type 2, the sidewalls of pillars were assumed to be vertical. The complex pillar geometry in dipping mines was frequently modeled using these two geometries. To capture a complete picture of the effect of seam dip on pillar stability, the modeled width-to-height (W/H) ratio of the pillars, in situ stress field, and pillars roof/floor interfaces were systematically varied to account for the potential distribution of values for these parameters across the underground stone mines in USA. Results from the numerical modeling indicate that dipping pillars have reduced strength compared with horizontal pillars. Also, an asymmetric failure propagation pattern could be obtained depending on an interaction between the W/H ratio, seam dip, in situ stresses, and pillar geometry.

Feb 5, 2021

By A. L. Holmes

This presentation in the open pit session deals with the development of a phosphate rock strip mine by CF Industries, Inc., a company that does not presently mine in the Central Florida Phosphate District. Land acquisition, engineering, financing and environmental permitting activities were begun in early 1975; site preparation, environmental monitoring and dragline construction began in mid-1975. The operation is due on-stream in late 1978. The reserve acquisition, permitting, and financing could each easily be developed into a separate paper of interest. Each, however, has been covered before for other mining ventures with similar capital and environment requirements. For that reason, I have chosen to discuss what CF Industries, Inc. is, why it is entering this new sec-tor of the agricultural chemicals business, and, to keep at least some technical basis, what design modifications are possible when the total mine output is used captively and it is unnecessary to have the flexibility to meet the numerous transportation and customer specification considerations. In an attempt to show the size and complexity of the CF organization, a brief description of existing facilities should help show why the big interest in mining phosphate rock.

Jan 1, 1977

By V. Aghazadeh, E. Bidari, M. Aazami

In this study, mineralogical and microanalysis characterization, as well as diagnostic leaching and cyanidation tests, were performed to gain a better understanding of the refractory nature of the arsenical zone of a Carlin-type gold deposit and also to evaluate possible treatment routes to maximize gold recovery. The results obtained showed that only 56% of the ore’s gold content is amenable to direct cyanidation. The majority of the remaining gold was found as submicroscopic gold and in association with sulfide minerals, such as orpiment, pyrite, and sphalerite. It was also found that despite the abundance of silicate and carbonate minerals in the arsenical zone, they do not play a key role in the refractory nature of the ore, and gold can be liberated from such minerals by appropriate grinding. The analyses further revealed that orpiment dissolves readily during cyanidation, and this dissolution retards the kinetics of gold extraction. Pyrite and sphalerite were generally found to occur in fine network texture and in association with quartz. Flotation of such auriferous sulfides may be difficult due to their oxidized surface. Fine grinding (−20 μm) was found to be partially effective in improving gold extraction.

May 28, 2020

By B. K. Cantrell

A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2, NO, NO2, SO2, diesel-exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive, but during the past several years, progress has been made in defining the problem. Results from epidemiological studies by Garshick, et al. (1988); animal inhalation studies by Mauderly, et al. (1986); Iwai, et al. (1986); and Brightwell, et al. (1986); and in vitro studies by Lewtas, et al. (1986), have provided sufficient data for the National Institute of Occupational Safety and Health (NIOSH) to recommend that "whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration," NIOSH (1988). NIOSH further stated that "though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk."

Jan 1, 1990

By R. R. Klimpel

The grinding of coal-water slurries has received increasing industrial attention during the last decade. In particular, there is long-term interest in the use of pulverized coal-water slurries to replace oil in combustion equipment and the development of coal gasification/liquefaction processes which require coal-water slurries as feed. More specifically, the use of coal-water slurries in gasification requires grinding a high density slurry containing the smallest amount of water consistent with slurry pumping and spraying. As part of a fundamental engineering research support program aimed at the industrial implementation of dense coal-water slurry grinding, this author has published several papers on how specific rates of breakage vary as a function of slurry rheology, Klimpel (1982, 1982/83). These papers demonstrated that there is a consistent pattern of change in specific rates of breakage of coal in dense slurries with controlled variations in slurry rheology. By matching rheological data with laboratory grinding results, it was possible to identify directly slurry conditions that correspond to: (1) slowing down of breakage rates, (2) the occasional acceleration of breakage of some sizes, and (3) conditions where chemical additives will increase rates of breakage.

Jan 1, 1990

By Robert H. Merrill

In 1960, the Kennecott Copper Corp. and the U.S. Bureau of Mines entered into a joint research program to determine the changes in stress, strain, and displacement created by changes in slope angles. The field site was the Kimbley Pit, located near Ely, Nevada; the supporting laboratory investigations were made at the Bureau's Denver Mining Research Center. Following a study to determine the rock stresses in the mining district, the strike and dip of geologic defects (fractures) in the rock, and the laboratory-determined strength of the rock, a new slope angle and pit configuration was selected, and instruments were installed to measure changes in stress, strain, displacement, microseismic noise rate, and sonic velocities at several points in the west wall of the pit. Between February and November 1966, the west slope was changed from an average angle of 45° to a new slope angle that started at 45° on the south wall, gradually increased to 57 ½ at the center of the west wall, and to 61° on the north wall. The pit was deepened from about 500 feet to about 550 feet. About 2.55 million tons of waste and ore were removed by stripping and mining.

Jan 1, 1968

By D. A. Poukhovski

Two integral components of the 30 CFR 48 training requirements mandated for new miners, newly employed experienced miners, and the annual refresher training of all miners are hazard recognition and prevention of accidents. In these categories, instruction shall include the recognition and avoidance of hazards present in the mine, and a review of accidents and their causes. Unlike instruction preparation for fact-based material, program development for hazard recognition places a particular challenge before safety-training specialists because they are often limited in their ability to adequately gauge the trainees' levels awareness prior to training. Further, they must also assure that the training is relevant, and it is presented in a thought-provoking manner. Computer-based instruction is particularly well suited for assisting trainers in developing hazard-recognition topics because it can be used in pre-training and post-training modes for assessment of training effectiveness, in addition to use as a presentation tool. Therefore, this paper will present a recent approach developed at Penn State to apply this technology for assessment and instruction of accident prevention through hazard recognition, with an application prepared for surface coal mines.

Jan 1, 1997

By R. R. Fernández

The Newmont roasting plant in Carlin, Nevada, commenced operating in December 1994. Over the years, refractory ores and pyrite concentrates from different gold deposits constituted the feed to the facilities. Historical plant performance indicated that the roasting temperature was the main variable affecting the structural characteristics of the calcine, which in turn affected the recovery of gold by cyanidation. Gold recovery as a function of roaster temperature has been closely monitored since October 2000. The original design temperature was 550° C. Lower roaster temperatures of around 500° C resulted in a gold recovery increase of more than six percent. This increase was directly related to an increase of the surface area of the calcine. The implementation of an ?intelligent? process control system helped significantly in achieving steady low roasting temperatures, thus obtaining high gold recoveries of 92 to 93 percent. Under these conditions, several roasting campaigns with high-arsenic-containing ores were conducted, which resulted in a significant decrease in gold recovery. The reduced gold recovery was caused by the loss of surface area (e.g., porosity) of the calcine as the arsenic content of the roaster feed increased.

Jan 1, 2010

By Myles E. Robinson

During the last decade there were pronounced changes in the competitive pattern of the fossill fuels It is proposed to trace these trends and describe inter-fuel competition, first as it relates to the economy as a whole and then more specifically to examine competition of the fossil fuels as these share the electric utility market. Table 1, Competitive Fuels and Water Power Used in the United States, 1950-1959, shows the growth in the consumption of coal, oil, gas and water power 'during the past decade. Uses which are not directly competitive among the fuels, such as tractor fuel, carbon black, and consumption of petroleum products in the making of synthetic rubber, have been excluded from these statistics. The experience of the three fossil fuels in competition since 1950 shows natural gas expanding more rapidly, than oil by roughly twice as much, 219.0 percent' compared to 124.1 percent growth in B.t.u.s of oil consumed in the ten-year period. Percentagewise, water power little more than held its own, and coal, including anthracite, actually decreased more than one-fifth.

Jan 1, 1961

By W. G. Miller

A series of computer programs for the analysis and mapping of coal-related data has been developed at the Illinois State Geological Survey; these programs, known collectively as the Coal Data System, represent the latest achievements in computer processing of geologic data at the Survey. Building upon programs previously developed in the Survey's Computer Services Unit, they expand the scope of the computerized data base that the Survey has been using for analyzing coal-related data. The System was partially developed during a joint study by the Illinois State Water Survey and the Geological Survey entitled, ?Coal and Water Resources for Coal Conversion in Illinois.? 2 In that study the available coal reserves more than 42 inches thick in the two principal coal seams throughout the state were mapped. The System was used to calculate the coal reserves and to report the average number of tons of coal in place per square mile in each township (Figures 1 and 2). It also produced maps of the coal features of sufficient quality to be printed on material that was scribed as master copy for the printing of full-color 1:500,000 scale maps (see Figures 3 and 4).

Jan 1, 1975

By Vernon N. Cox

From comments and questions concerning the meaning of USNR, and "why is the Navy in the mining business?" I believe it is worth while to establish the background and purpose of our company. We are a stock company formed by the purchase and reorganization of a company known as the U. S. Natural Gas Corporation. In May 1969, a group of investors with Mr. Robert L. Katz as president and chief executive officer, created United States Natural Resources, Inc., to develop and purposively use our Natural Resources in four areas: 1. Mines and Minerals 2. Forest Products 3. oil and Gas 4. Recreational Lands As final proof that we are not a government organization, I simply state. "We pay taxes." The mining division was formed in October 1969, with the completion of the merger of USNR and Vibration Measurement Engineers, Inc., Of Evanston, Illinois. Throughout the industry we were known as "VME," our company supplied consulting service in the field of seismic energy control, mining consulting and. we operated drilling, blasting and, contracting organizations in several areas of the country. Since that time we have developed and acquired producing properties in Quarrying, Coal Mining and Cement Copper Production.

Jan 1, 1971

By David D. Eyer

Since the decade of the 1990s is nearly upon us, I have focused on what I see are the likely trends featured in new large underground coal mines 10 years from now. I do this from the vantage point of having been involved in the installation of large mines for more than twenty years. Little of the equipment resources we have available today was unknown when I entered the coal business in 1960. There were continuous miners, longwalls and diesel-powered equipment in Europe, monitoring systems, computers, heavy media separation systems, froth flotation and conveyors then as there are now. A substantial evolutionary process has occurred with these and other mining machines and processes. Some evolved only to die out, such as boring-type continuous miners; others, such as longwall systems, flourished. My intuition tells me that since there have been largely evolutionary rather than revolutionary developments in the near past, the same is true of the future, at least for the next 10 years. In other words, the elements of what are in the future are with US now. Some, such as computer-based applications, may evolve beyond our wildest dreams -but I doubt it.

Jan 1, 1988