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By Richard L. Sanford

This paper summarizes the results of the development of a Directory of Computer Programs Applicable to U.S. Mining Practices and Problems. The Directory is funded by the U.S. Bureau of Mines and includes a sampling of computer usage in operating and manufacturing companies, consulting firms, computer companies, research organizations, universities, and various U.S. government agencies. General references to computer applications throughout the mining industry are discussed as well as the availability of programs to interested organizations or individuals.

Jan 1, 1978

By C. W. Lockhart

Strength evaluation programs, based on sub- jecting a number of 5-718 inch (0.15 m) diameter core samples from highly fractured or poorly consolidated rock, to triaxial compression tests, have been successfully completed. An innovative approach was required since con- ventional methods with similar materials had not produced reliable results. Drilling methods were modified, and specially designed transparent core barrels were used. Sample preparation was successfully accomplished by using speciallydesignedtools and unorthodox hand- ling methods. Initial tests were carried out on weathered oxides from an open pit copper mine. The technique was later used successfully where the test material was weak, friable coal. The procedures used offer a practical method of testing weak materials where conventional methods would not be successful.

Jan 1, 1980

By D. R. Taylor

Treatment of bentonite clay with mineral acids yields a modified clay product of high surface area and acidity which exhibits enhanced adsorptive and catalytic properties. A highly specialized segment of the clay industry based on this process has evolved into worldwide business with a capacity of about one-half million tons/yr. This paper will present data on the chemistry, mining, manufacturing and applications for acid- activated clays.

Jan 1, 1986

By Amir Karami, Scott Munro

This paper focuses on remediation of a 3.6 km long water conveyance tunnel that suffered two large falls of ground (FoGs), one of which subsequently progressed to the ground surface, resulting in full collapse of the tunnel. The tunnel is part of a network of water conveyance tunnels and open channels that direct water into two turbines located in an underground powerhouse, originally constructed in the 1970s. At the time of construction, the tunnel was partially supported with shotcrete or rock bolts, with no further ground support added since construction. Two sonar surveys in 019 and 01 identied two adacent large FoGs in the tunnel, approimately 1.2 km from the tunnel outlet. Historical geological and geotechnical information indicated that the FoGs occurred within a 60 m wide fault zone. Remediation plans were developed, which included stabilization of the outlet channel, the portal, the tunnel leading up to the FoG areas (1.2 km length) and the FoG areas. Several remediation options were considered to restore the tunnel, including construction of a diversion tunnel to bypass the FoGs or remediation of the FoG areas with steel ribs and backlling the void above the FoGs to surface.

Jun 23, 2024

By J. James Eidel

Geological interpretations generally require projections from direct observations at the earth's surface. Crustal projections include mineral deposits as well as the geochemistry of the crust and its fluids, structure and tectonics. Drilling offers opportunities for verification of the required projections, and is thus a required step in furthering crustal understanding. Like any new science, the direct observations that drilling provides commonly generate major surprises and stimulate totally new ideas. Drilling is costly. There are many critically important scientific problems with societal and potential economic benefits in mineral deposits which have not been drilled because the holes are difficult to justify as economically sound risks for private capital. Such holes, however, are highly justifiable research goals for government because of the significant new opportunity for ore deposit insight and exploration that they afford. The earth science community is prepared with excellent drilling projects for research in mineral deposits.

Jan 1, 1985

By I. Iwasaki

The effects of autogenous grinding and conventional grinding on the floatabilities of copper-nickel sulfides were investigated as a part of a pilot-plant development project on the differential flotation of Duluth gabbro. At the same mesh-of-grind copper, nickel, and cobalt recoveries were higher and residual sulfur in the flotation tailings was lower with the autogenously-ground pulps. With the ball-mill-ground pulps the residual sulfur in the tailings could not be lowered to the level attained by the autogenously-ground pulps even at increased levels of the collector addition. From mineralogical examinations of concentrate and tailings samples, an electrochemical interaction between grinding media and sulfide minerals was thought to have a greater effect on sulfide mineral flotation behavior than the breakage characteristics of the ore samples in these two types of mills.

Jan 1, 1981

By Douglas A. Sloan

Who would believe that young elementary school children could understand something as complex as the mining industry? THE CHALLENGE The challenge of accomplishing this is tremendous. An examination of Canadian school children indicated that they knew very little about the world of work in general, and hardly anything about the mineral resource industry in particular. It calls to mind the story about two youngsters who decided to play house. The little girl played her role well as she went about the house doing things she had watched her mother do every day. When it was the little boy's turn, he grabbed his lunch, waved goodbye to his "wife", jumped on his bicycle and pedalled furiously down to the end of the driveway -- where he stopped. The youngster explained that he saw his dad go out of the driveway each morning, but he didn't know where he went, or what he did on the job. When you stop to consider the number of families today with two working parents, you can begin to appreciate the importance of the opportunities for role identity provided by this project.

Jan 1, 1979

By G. J. Joy

Although rates of pneumoconiosis in coal miners have declined substantially in the United States since the passage of the Federal Coal Mine Health and Safety Act of 1969, new cases continue to occur, including cases of rapidly progressive disease. In contrast, Australia's underground coal mining industry has reported few new cases of pneumoconiosis for more than 20 years. Mortality from coal workers' pneumoconiosis in official health statistics and the prevalence of pneumoconiosis among miners screened in X-ray surveillance programs are also lower in Australia. The U.S. National Institute for Occupational Safety and Health (NIOSH) was requested by both industry and labor stakeholders to examine this issue, with the ultimate aim of reducing the rate of pneumoconiosis among U.S. coal miners. A number of factors, including coal dust exposure, silica exposure and coal rank were examined as potential contributors to the above noted differences. Comparison of coal rank data from each country did not illuminate the issue. Air sample data from the coal mining industries in both countries show that coal dust levels in Australian mines are somewhat higher than those reported in similar U.S. mines; however, quartz exposure for Australian miners is lower than for many U.S. miners. If quartz is contributing to the greater number of cases of pneumoconiosis in the United States, more effective dust control measures, as well as an independent exposure standard for respirable quartz in coal mining, should be implemented to reduce this potentially disabling condition.

Jan 1, 2012

By T. E. Mccandless

Detrital minerals of mantle origin have been found in the Green River Basin of Southwestern Wyoming (Figure 1). Pyrope, pyrope-almandine, and chrome-bearing clinopyroxene and orthopyroxene occur on the antmounds of Pogonomyrmex Occidentalis. These antmounds are a common sight throughout the western U.S., and were used by early paleontologists as fossil mammal collection sites. The mound is composed of two types of material; (1) soil excavated during the digging of the nest below the surface (maximum depth 3 meters) and (2) larger grains collected from the surface and placed on the mound, probably to prevent erosion. The selection of grains to armor the mound seems to be based largely on the mean diameter of the grain, with other factors such as weight, sphericity, roundness and composition in decreasing order of importance (Wheeler and Wheeler, 1963). The minerals of this study happen to fall within that mean diameter range. The garnets are found on the mounds as 3-6 mm diameter subrounded to subangular grains. The pyroxenes are also 3-6 mm in diameter and are most commonly subangular laths. The minerals themselves show evidence of abrasion, such as frosted surfaces and rounded edges. Orange peel texture is present on some of the grains, which suggests that kelyphitic rims were once present, but have been removed. Also, no similar minerals were found in sieved soil auger samples to depths of 2 to 6 meters taken near the antmounds. These observations imply a distal rather than proximal source for the minerals. Lamproitic rocks of upper mantle origin are found bordering the "Green River Basin. The best known are the Leucite Hills, a series of ultrapotassic volcanics found on the north flank of the Rock Springs Uplift (Carmichael, 1967). Minor occurrences of mica peridotite and ultrapotassic volcanics are also found on the western end of the Uinta Mountains in Utah (Best, et al, 1968). None of these rocks are known to contain minerals like those on the antmounds. The garnets are comprised of purple chrome pyrope, red chrome pyrope-almandine, and pink to orange low chrome pyrope/pyrope-almandine. Oxide statistics for these groups are summarized in Table 1. These three groups are distinct when their Cr203 values are plotted against magnesium number (Figure 2). The chrome pyropes are highest in Cr203 (1.28-2.66%) and have high, restricted Mg number values (0.781-0.826). The chrome pyrope almandines have similarly high Cr203 (1.29-2.62%) but a lower Mg number range. The low chrome pyrope/pyrope-almandines have the lowest Cr203 content (0.09-0.73) and the widest Mg number range (0.534-0.836). Using the classification scheme of Dawson and Stephens (1975) the chrome pyropes are most similar to garnets derived from kimberlite and from garnet lherzolite, websterite, and harzburgite xenoliths in kimberlite. The chrome pyrope-almandines and the low chrome pyrope/ pyrope almandines are similar to garnets derived from eclogite nodules (Figure 3).

Jan 1, 1984

By K. T. Stafford, N. A. Iverson, V. T. McLemore

Laramide porphyry copper deposits are large, low grade (<0.8% Cu) deposits that contain disseminated copper minerals, breccias, and stockwork veinlets of copper and molybdenum sulfides associated with porphyritic intrusions in Southwestern New Mexico. Critical minerals, such as PGEs, tellurium, indium, germanium, and gallium are recovered from the anode slimes remaining after copper is refined. Detailed age dating, mineralogy, geochemistry, along with geologic mapping could refine the location of critical minerals within specific systems and could identify porphyry systems with elevated critical minerals that could become economic, in addition to the already produced copper, gold and molybdenum.

Feb 1, 2023

By John Marsden

Despite the recent pullback in metal and mineral prices, and the associated market adjustments, the mining industry is still facing a serious issue with the declining availability of graduate expertise. This is due to a combination of an aging workforce, retirements and retrenchments, coupled with a lack of suitably qualified graduates entering the workforce. The issue has certainly improved since 2004 when the industry picked up the rates of hiring graduate engineers and mining/mineral school enrollments picked up in response. This hiring effort has helped to cover the ?gap? years from about 1985-2000, when industry demand for graduates was particularly poor. However, the recent market pullback is likely to set back this progress, as recruitment and hiring wavers as a result of cost cutting measures and economic uncertainty. A key issue for the mining industry is how to ensure the survival and growth of relevant ?core? degree programs. Such programs include mining, metallurgical, mineral processing and geological engineering. The mining industry needs a healthy, high-level education program to ensure an adequate supply of appropriately qualified graduates for the mining industry. Two-thirds of the professionals entering the minerals industry who graduated within the past 40 years graduated prior to 1985. Since 1985, we have been living off the legacy of graduation classes from the mid-1970s and early 1980s. It is estimated that we have been producing graduates at approximately 40 to 50 percent of the sustaining rate since about 1985. Further growth in the domestic industry would increase graduate requirements significantly, and the export of U.S.-graduates to other parts of the world (as is currently occurring) also impacts the total graduate requirements.

By Felicia F. Peng

One of the serious environmental problems related with the extraction of coal for carbon and energy resources is that upon preparation of coal a large quantity of fine coal has been discarded and/or lost to tailing impoundments. These problems present hazardous conditions to the local community. Also, the precious heating value of energy resources has been wasted and Left unrecovered in the tailing impoundments. Both RCR and SMRC ACTs recognize and mandate an investigation into slurry impoundment problems, including consideration of potential use of those coal fines in the tailing ponds. Bituminous coal producing district 46 encompasses the northern panhandle of West Virginia. The major producing seam in this district is the Pittsburgh coal, 1-7 meters thick. 75 percent of the coal producted in this district is deep mine. This district produces approximately 3 million tons of coal waste materials annually. One of the coal preparation plants in the district which we have visited has been processing Pittsburgh too. 8 seam coal for the past ten years. The characteristic data of the Pittsburgh raw coal is shown in Table 1. The raw coal produced in this district is characterized by its high heating value, high ash and high sulfur contents. The coal preparation plant flowsheet designed and used to process this Pittsburgh raw coal prior to 1979 is shown in Figure 1. It was a partial coal cleaning plant&apos; with 1 092 mt/hr designed capacity, which consisted mainly of a coarse coal cleaning circuit. The rejected fine particles in the size range of -600µm which consisted of vorsiv underflow and cyclone underflow from clean coal streams and spiral classifier overflow from refuse stream were settled down in a thickener with the aid of anionic flocculant prior to being pumped to the tailing ponds for disposal. Figure 2 shows that the same coal preparation plant in Figure 1 was modified to a semi-complete coal cleaning plant and expanded its designed capacity to 1 820 mt/hr, when market of coal fines becomes feasible in 1979. Tabling in the clean coal circuit and thermal dryer in the dewatering circuit were added to the flow sheet. The purpose is to recover more coal fines, reduce more pyritic sulfur and ash contents in coal and also to reduce solid waste material to be stored into the slurry impoundment, giving them a Longer Life. The rejected fine particles fed to the thickener are clean coal fines from two cyclone overflows and the fine refuse from the rufuse cyclone overflow. The clean coal fines presently lost to the tailing impoundments are in the size range of -150 µm and constitute about 5 percent of the overall plant feed. Total amount of tailing waste material accumulated in a tailing impoundment is estimated at 1.3 million metricton for the past ten years.

Jan 1, 1982

By Jennifer L. Bell, PATRICK L. YORIO, Emily J. Haas, Susan M. Moore, Lee A. Greenawald

Although researchers have struggled to replicate Heinrich’s safety triangle findings (Heinrich 1931) for various reasons (e.g., no access to his original database and it is unclear if the database was of a single establishment/operation or for an entire industry), the occupational safety community has continued to adopt and expand the applications of this theory (e.g., McSween 2003). Within the mining industry, the potential exists for operations and companies to use concepts from the safety triangle as a way to inform or challenge the practices employed within their health and safety management systems (HSMS) to prevent incidents (Backlund 2016). This paper considers data obtained from the Mine Safety and Health Administration’s databases and demonstrates the validity of applying the safety triangle theory at the mine level. The results support the use of this theory and demonstrate that lower severity incidents can predict fatalities in a subsequent year where significant nuances and caveats to applying the theory are identified and discussed.

Jul 25, 2020

By Victoria Vaccarezza, Corby Anderson

The demand for rare earth elements for everyday technology and applications has initiated much research into the extraction and recovery of these rare earth elements. An otherwise unknown group of minerals, eudialyte is a zircon silicate consisting of rare earth oxides (REO), contained in a unique mineral structure and represented by a complex chemical formula. Research into extraction and recovery of rare earth elements involves various beneficiation and hydrometallurgical techniques. The goal of beneficiation being to efficiently liberate and upgrade the REO content, followed by hydrometallurgy to extract the desired elements. This overview will discuss previous research on treating eudialyte group minerals via different mineral processing and extraction techniques.

By M. J. Zdunczyk

The final 1995 figures on industrial sand and gravel have not yet been compiled by the US Geological Survey (USGS). There is usually about a nine-month lag time in receiving and compiling this information. However, USGS estimates that domestic production of industrial sand and gravel will increase about 4% to 28.2 Mt(31 million st). The average unit price is expected to increase as well. The top five producers during 1995 were Unimin, US Silica, Fairmount Minerals, Oglebay Norton and Morie Co. Glass manufacturing for containers, automobiles and buildings was mixed during 1995. Containers, the largest consumer of silica sand, remained steady, with regional increases. However, silica use in glass containers face increased competition from plastic and recycled glass (cullet). It was reported that the Pepsi Cola announced plans to replace glass containers with plastic during 1996.

Jan 1, 1996

By M. L. Bricker

The Jim Bridger Mine is operated by Bridger Coal Company and is located in Sweetwater County, 35 miles (56 km) northeast of Rock Springs, Wyoming (USA). The general location of the mine site is shown on Figure 1. Bridger Coal is a joint venture of NERCO Coal Corp, the operator, and Idaho Energy Resources Company. The permit boundary encompasses in excess of 20,000 acres (81 km2) and is nestled against the western side of the Continental Divide. Production started on July 3, 1974, and the mine has produced approximately 90 million tons (82 million t) while moving approximately 450 million cubic yards (344 million m3) of virgin earth. Annual production averages 5 to 7 million tons (4.5 to 6.4 million t) of run-of-mine coal. Coal is consumed on site by the Jim Bridger Power Plant, a 2,000-megawatt generating station, and the electricity is transmitted to the Pacific Northwest power grid (Oregon, Idaho, Northern California, etc.).

Jan 1, 1991

By Goran Mathisson

In several investigations the correlation has been studied between the fuel consumption and the reducibility of the charged material in the zone of indirect reduction in the blast furnace (1, 2, 3, 4, 5). It has been found that increased reducibility allows greater gas utilization which accordingly lowers the fuel consumption. In direct reduction units this relation has not yet been fully established partly owing to the lack of accurate test methods and experience with different materials as regards reducibility. However, since the production rate in a direct reduction unit is closely related to the time required to reach high degrees of reduction, the reducibility must be regarded as one of the most important properties of the material.

Jan 1, 1979

By Madan M. Singh

Increasingly, geotechnical data are being collected for various types of coal development projects. In many cases, a specific design concern is addressed. However, many data collection programs are not intended to immediately support mine design activities or to resolve a specific concern. The following discussion describes some current geotechnical approaches in mine planning, development of reserves, and peripheral activities. Types of Data Collection Programs Geotechnical data collection is increasingly becoming a part of standard coal exploration programs, performed along with stratigraphic evaluations and coal quality tests. The aims of such programs vary. The purpose of the exploration may be to fill out the portfolio on a block of reserves that is to be sold, leased, or held for potential future development. In such a case, a generic suite of geotechnical data are collected. The resulting engineering reports may touch on the more well known mining problems of the area, but detail may be lacking. The geotechnical data are mostly intended to enhance the saleability of the package. Mine design alternatives are generally not addressed.

Jan 1, 1985

A PDP 11/34 computer has been inter- faced to existing instrumentation in a 400 tph rod-mill/ball-mill grinding circuit and programed with a Kalman filter to estimate several unmeasured variables. A dynamic two-size- fraction model of the circuit is used to predict the complete state of the circuit including particle size distributions around the circuit, mass holdups and flowrates, the ball-mill grinding rate, water additions and cyclone parameters. Online measurements of sump level, slurry densities and product particle size are used to update the model values sequentially on a 20-second interval. This procedure results in optimal estimates of circuit variables given the relative reliability of measurements and the accuracy of the model.

Jan 1, 1983

By F. E. Senftle

Preliminary geophysical surveys for nickel deposits are usually carried out by airborne magnetometer and surface electrical methods. Once an anomaly is discovered by these techniques, one must resort to chemistry to identify nickel and determine its concentration. Consequently, a method to determine nickel quickly and quantitatively at the exploration site could help guide detailed sampling and provide analytical data that might otherwise be delayed at distant laboratories. In addition, borehole probes capable of indicating nickel in the rock adjacent to the hole, should prove attractive to the exploration geologist. With these needs in mind, preliminary investigations have been made to demonstrate an in situ analytical technique which appears feasible for nickel exploration. The method depends on the very high energy gamma rays emitted when nickel absorbs a thermal or low energy neutron. These neutron capture gamma rays should be distinguished from the lower energy gamma rays emitted during decay of radioactive nuclides as in conventional activation analysis.

Jan 1, 1971