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By C. M. St. John

A series of analyses of possible mining excavations associated with the development of copper nickel deposits of the MINNAMAX site in Northeastern Minnesota is presented. Specific areas such as roof and pillar stability and excavution orientations are addressed. The majority of these analyses were conducted using a boundary element method but some cases were also analyzed using the finite element method. Comparable results were obtained using the two methods but the boundary element method required less data preparation time and computer run time. Results of the analyses, as well as indicating the capabilities of geotechnical numerical models, provide some insights into behavior around multiple excavations in jointed rock.

Jan 1, 1979

By Tim F. Dyson

Feasibility of employing automated processing and detection techniques in the mine disaster communications problem is demonstrated. Efficient processing methods are developed. These methods have been demonstrated both in a laboratory and in a field environment. Evalua¬tion of existing computer capacity is given along with recommendations for expansion.

Jan 1, 1981

By W. R. Byrnes

This project was initiated on October 1, 1980 and will be completed on December 31, 1983. The project was Initially approved and funded by the Office of Surface Mining and subsequently was moved to the jurisdiction of the Bureau of Mines. It was administered through the Indiana Mining and Mineral Resources Research Institute. The research was done to assess reforestation success and ultimate productivity for areas reclaimed under the Surface Mining Control and Reclamation Act of 1977 (P.L. 95-87). The Permanent Regulatory Program for implementation of P.L. 95-87 Includes provisions for revegetation that require seeding of ground cover plants to control erosion until permanent vegetation such as tree species Is established, and restoration of mined land to its original or better productivity. Much of the land to be surface-mined presently supports forest cover and it is anticipated that reconstructed minesoils will exhibit high productive potential for hardwood tree species. Hence, information was needed on compatibility of ground cover and tree seedlings when established concurrently as well as on revegetation success under postmining versus premining conditions.

Jan 1, 1983

By Jeffrey P. Schubert

The study site in northeastern Illinois underwent surface mining for coal in 1943 and was reclaimed by the state of Illinois in 1972-1973. Additional soil amendments and seed were applied to the spoil surface in 1975-1980. Previous studies in 1975-1978 had shown that the surface spoil materials and five final-cut lakes at the site were quite acidic and the lakes contained high concentrations of sulfate and dissolved metals. Surface runoff water from monitoring plots in 1976 were only moderately acidic and the mean concentrations of most dissolved metals and sulfate in the runoff waters were less than 25% of the concentrations found in Lake B. By 1980, vegetation had become well established over most of the mined area. However, the five final-cut lakes (Lakes A-E) remained acidic. The purpose of the study reported here was to determine the physical and geochemical subsurface conditions of the spoil materials, the hydrologic flow system within the spoils, and the magnitude of acidic spoil leachate migration into the lakes and into the wetland prairie north of the mine site. Lakes A, B, C, and E were still very acidic in 1980-1981 (pH range: 2.9-3.4; aridity range: 110-860 mg/L as CaCO3). Lake B had the worst water quality, with mean concentrations of dissolved aluminum, iron, manganese, and sulfate of 75, 25, 37, and 3340 mg/L, respectively. Shallow groundwaters in spoil materials around Lake B had a lower pH and about two to four times greater concentrations of aridity, aluminum, manganese, zinc, and other metals and nearly 20 times greater dissolved iron than the water in Lake B. The shallow groundwaters in undisturbed soils and bedrock 10-30 m north of the mine site spoils generally were alkaline, but did contain occasional moderately high sulfate and metal concentrations. Pumping tests and recovery tests conducted in piezometers showed hydraulic conductivities of spoil materials ranging from less than 10- to 10-5 m/s; hydraulic conductivities of natural soils and bedrock were measured between 10-10 to 10-7 m/s. Water levels in spoil materials increased rapidly in response to rainstorm events and the recession curves were relatively quick to decline, lasting only two or three days. Quick infiltration of rainfall into the spoil surface and percolation down to the water table caused a rise in groundwater levels and movement of spoil groundwater into the lakes. This groundwater component in the lake water budgets could account for most of the water quality problems occurring in the acid lakes.

Jan 1, 1984

By Timothy J. Rohrbacher

This report presents results from an ongoing U.S. Bureau of Mines study defining domestic coal reserves. Examinations of five 7 ½ -minute central Appalachian quadrangles have been completed to date. Only 26.4%, 5.0%, 6.5%, 8.2%, and 4.2% at the coal resources remaining in the Matewan, Boltsfork, and Hoskinston, KY; Vansant, VA; and Beckley, WV quadrangles, respectively, constitute economically recoverable reserves. An evaluation of the coal mining industry's impact on the economy of Pike County, KY, wherein the Matewan quadrangle is located, was also completed in order to provide a basic understanding of the influence of coal mining on the local economy. Results show that coal mining is the only major income producing industry in Pike County, accounting for about 46% of the county's income, and 21% of the total available employment, in the base year 1990. If similar results are found in subsequent investigations, a strong argument can be made that traditional coal producing regions may soon be experiencing resource depletion problems far greater and much sooner than previously thought. This will affect not only the coal industry but, given the obvious dependence of Pike County's economy on its coal mining industry, the entire social and economic infrastructure of large areas.

Jan 1, 1994

VOLUME I Volume I of this three-volume report is the result of development of a comprehensive, coordinated approach to site data-acquisition activities to produce key plans and reports during the evaluation and development of a surface coal mine. A logic diagram illustrates activities in the planning and decision-making process from exploration through post-mining monitoring. The report briefly discusses major elements, other than the site environment, which influence development of mining and reclamation plans and refers to other readily available literature for details outside the scope of this study. The essence of the rationale is shown to be the 1 employment of necessary skills at the proper time to evaluate specific data ' requirements and integrate them into a cost-effective program to produce initial and major feasibility reports, mining, and reclamation plans, and the environmental impact assessment.

Jan 1, 1976

By J. H. Nixon

A three phase program evaluated commercial proximity warning devices, developed and designed a microprocessor-based electrostatic field measurement instrument, and utilized this instrument to investigate the electro-static fields about power lines. The Phase I program consisted of test and evaluation of these commercially available proximity devices. The evaluation results were reported in the Phase I report entitled ?Evaluation of Proximity Warning Devices? dated 22 February 1980. The Phase II program resulted in the design and development of a microprocessor-based Distributed Sensor A.C. Electrometer which measures the electrostatic field present at 17 discrete locations along a crane boom. Operator control of the measurement system allows simultaneous electric field measurements from 17 probes, print out of the electric fields measured, and data archiving on magnetic tape for post measurement analysis. Under the Phase III program, electrostatic fields around a crane boom were measured by the instrument at 17 high voltage power lines of various voltages and geometries. The electric field data was processed and plotted versus boom distance from the power line. Analysis of the electric field data indicate that the distances at which a single sensor alarm will activate, vary by a factor of 3 to 1. This is due primarily to variations in boom orientation. The results also indicate that in the case of multiple power lines, a single electrostatic field sensor cannot reliably be used to determine the distance from a power line.

Jan 1, 1982

VOLUME II Volume II, in conjunction with Volume I, is a general guide to the selection of cost-effective methods of site data acquisition in all geologic environmental, and socio-political circumstances. The judgement of a generalist or trained specialist must be relied upon in the final analysis to design the optimum program for a specific site.

Jan 1, 1976

VOLUME III The objective of Volume III of this report is to provide a concise review of six major types of legal constraints, controls, and regulations on surface coal mining in the United States, as of January, 1976. At the same time, an attempt is made to format the details of federal and state exploration, mining, and reclamation regulations such that point-by-point comparisons can be made and updated as revisions occur. Thus, Volume III should provide both an executive overview and a user's manual of legal controls of surface coal mining.

Jan 1, 1976

By Peter Murphy

This report (arid related appendices) provides a description of the functional design specifications, engineering design specifications, and program of instruction for development of a training system for dragline equipment operators. Based upon a task analysis and training system analysis prepared under Phase I, Phase II efforts expanded upon and refined the functional design specifications. The training hardware components have been developed to a point shy of system fabrication. A detailed outline of the porgram of instruction and content sequence has been prepared. The objective of the training system described in this report is to provide new operators of dragline equipment with the requisite skills and knowledge to assure cost-effective development and an adequate supply of our human resources.

Jan 1, 1976

By G. Ahnell

Throughout portions of four (4) heavily mined Appalachian states subdivided by the Mine Safety and Health Administration (MSHA) as: District 3 -Northern West Virginia and Maryland; District'" -Southern West Virginia; District 5 -Virginia; and District 6 -Eastern Kentucky, active coal mine waste embankments associated with mechanical and/or chemical coal processing facilities of various levels of coal preparation were inventoried. For each site plant specifications, disposal techniques, embankments' characteristics, and coal source data were accumulated. Mapping at 1: 24, 000 and 1: 250,000 scale and Disposal Site Characterization forms were developed to present the findings. Associated abandoned surface and underground openings near each site were also indicated as well as locational data for each site and the areas environmental conditions - temperature, precipitation and vegetation types. A state-of-the-art review of coal preparation, waste disposal, and alternative uses of coal waste is also included.

Jan 1, 1982

[Module 10. Internally Cued Operating Contingencies Prerequisite: Modules 1-7 - Estimated Instructional Time: 2.42 hrs. Module Abstract Trainees, using programmed instruction, describe the cues, consequences, operational sequences, and possible causes resulting from loss of air pressure from power fluctuations, and from a failure of the automatic lubrication system. Although some of the contingencies may be initially signaled by an alarm or from the oiler, each trainee will demonstrate proficiency in the appropriate operating techniques and procedures. This module also includes a review component for those trainees identified in the assessment exam as requiring less detailed instruction.]

Jan 1, 1976

By Kent W. Hawley

An improved visibility system was developed for use on the large (100 ton+) haulage trucks typically operated in open pit and surface mines. The improved visibility system provides the truck driver' with a means of viewing hazardous situations that occur in the extensive blind areas adjacent to his true. The cost effective, reliable, visibility system consists of a closed-circuit television three unique fresnel viewers, and two improved mirrors. This report describes the visibility problems of Large trucks in the surface mining environment, shows the performance of existing mirrors, substantiates concept selection, and describes the prototype improved visibility system.

Jan 1, 1978

By John L. Dahle

This report documents the research efforts that were undertaken to design, install and test noise abatement devices for use on off-highway haul trucks operating in surface mines. The objective of the program was to reduce the environmental noise from haul trucks. The noise reduction devices that were developed utilized existing technology and were tested on a 50-ton haul truck. The efforts emphasized the reduction of noise emitted from the engine compartment which included the use of side shields, sound absorbing material, improved radiator shroud design, and a modulating clutch fan. Noise tests were conducted using modified SAE test procedures for measuring sound levels around a stationary and moving machine, and inside of the operators compartment. Test results showed a maximum of 4 dB(A) reduction measured 16 feet from the truck. Interior cab noise was reduced 6 dB(A) with the windows and vents closed.

Jan 1, 1983

By Steven A. Fechner

In 1991 and 1992, the Bureau of Mines completed chromium, platinum-group metals (PGM), and tin investigations, and started indium, manganese, titanium, and vanadium investigations in Alaska. These studies were done as part of the Site Specific Minerals Investigations project. As a result of this work, the Bureau found PGM-bearing composite plutons in the Yentna River area of the Alaska Range, which are chemically similar to composite plutons in other parts of the Alaska Range and to Ural-Alaskan type complexes. Previously unknown chromium and PGM occurrences were found in the western Brooks Range. A compilation report on the Bureau's chromium and PGM investigations in the western Brooks Range was also published. Indium was found in anomalous concentrations at the Lost River tin deposit. Small occurrences of manganese were located, mapped, and sampled in the Wiseman and Chandalar quadrangles, and in the Liberty Falls, Prince William Sound, and Homer areas. Tin occurrences in western Alaska were summarized in three Bureau open file reports. The beaches near Cape Yakataga and Yakutat were evaluated for their titanium potential and a sampling methodology was developed. Vanadium investigations included examining streams in the Wiseman and Eagle areas that contained anomalous vanadium values. In the Eagle area, high vanadium, uranium, and copper values were found in the basal layers of the Road River formation.

Jan 1, 1994

By D. S. Kimmel

The Bureau of Mines sponsored development of a system to remotely energize and de-energize the trolley wire in a section in response to demands from vehicles as they enter and leave the controlled section. The system developed utilizes a detector/actuator that controls a dc contactor at the outby end, and a 3 kHz oscillator at the inby end. A prototype system has been built and installed at the Bureau's trolley test site at Bruceton, Pennsylvania which has demonstrated the ability to also provide load discrimination for faults of 300 amperes or more. The system could readily be modified by locating the oscillator on the vehicle to provide automatic de-energizing of the trolley wire when the vehicle's pole is removed or the vehicle leaves the section.

Jan 1, 1978

By Dennis R. Kasper

This study evaluates selective environmental impacts of two distinct in situ mining techniques. In situ leaching of uranium, porphyry copper and native copper and in situ borehole (slurry) mining of uranium, sandstone, and pebble phosphate ores are the techniques and minerals investigated. The potential impacts onsite in the desert southwest (porphyry copper), Michigan (native copper), Texas and Wyoming (uranium), and Florida and North Carolina (phosphate) are addressed and discussed. The study emphasizes those impacts which are unique to in situ solution leaching and borehole slurry mining. Impacts which are characteristic of all construction projects in the general geographical areas investigated, such as socioeconomic effects on surrounding communities and site-specific impacts, such as rare and endangered species, are beyond the scope of this study. For each of the in situ processes and associated ores investigated, the physical and chemical characteristics of the systems are described, the toxicity of the leaching solutions are presented, and the potential impacts on the environment are developed.

Jan 1, 1979

By GJ Hundman

The Multiple Unit Continuous Haulage (MUCH) System was designed to provide the capacity to continuously convey coal from the mining machine to the main haulage belt. The MUCH System has an operator who steers the lead vehicle, ever following the mining machine. All the remaining vehicles follow the path of the lead vehicle, with their conveyors automatically lining up between the lead vehicle and mine section panel belt. This is accomplished by mechanical linkages on the vehicles which are interconnected by steering bars between vehicles (patent pending). The MUCH System has an operator who steers the discharge vehicle when outby travel is required. Outby travel is just like inby, with each vehicle following the path of the preceding vehicle. Surface tests overwhelmingly indicate the "UCH System should track/retrack successfully in square pillar underground room and pillar coal mines with 18 ft. wide entries and slopes up to 10 percent. For 60 degree pillar plans the minimum entry width required is 15 ft. Surface tests also indicate the MUCH System will convey over 8 TPM of coal around 90 degree corners without excessive spillage.

Jan 1, 1983

Auger operations produced 14 million tons of coal in 1974, or approximately 5% of all surface mined coal. It was the most efficient of all coal mining methods, producing 40.0 tons per man-day. Exhibit 1.1 gives a breakdown of productivity of all coal mining methods. Exhibit 161 PRODUCTIVITY OF COAL MINING METHODS (Short tons per man-day) [Method - 1971 1972 1973 1974 Conventional 11.00 10.00 9.75 9.30 Continuous 13.00 12.50 12.25 11.90 Strip Mines 35.69 35.95 36.00 36.00 Auger Mines 39.00 43.00 45.33 40.00 ] Unlike other surface mining methods, augering produces clean coal, largely uncontaminated by foreign materials, other than those existing in the coal seam itself. However, compared to other methods, the coal recovery rate is relatively low. For example, a triple-headed auger in a 35-inch seam would recover approximately 50% of the coal in the seam as compared to a 90 to 95% recovery rate for strip mining and a 55 to 65% recovery rate for deep-mining. The low auger recovery rate is due to the circular cuts and pillars left in the seam.

Jan 1, 1975

By Paul J. Guay

This report presents the results of evaluating a longwall mining system specifically designed to extract a very deep web (60 inches or deeper) from a longwall panel. The report includes a productivity and cost analysis comparing the new mining sys-tem with a high capacity conventional longwall operation taking a 30-inch wide web. The analysis shows the new system will increase annual production 44 percent and decrease cost per ton off the face 21 percent. The report also includes conceptual drawings and specifications for a high capacity four-drum shearer and a unique shield type of roof support specifically designed for very wide web operation. The advantages and problems associated with wide web mining are discussed in general and as they relate specifically to the equipment selected for the new mining system. The study concludes by recommending that surface coal loading tests be conducted as the follow-on work.

Jan 1, 1978