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By R. S. Olsen

The Bureau of Mines is engaged in research to recover aluminum from kaolinitic clay and other nonbauxitic domestic resources. As part of this work, calcined Georgia kaolin was prepared by a process that prevents slime formation and makes the leached residues fast settling and easy to filter. The leaching reaction for calcined kaolinitic clay in a 5 pct stoichiometric excess of boiling 23-to 26-pct HCI was found to be zero order. Rate constants based on the weight-fraction of aluminum in the clay were found to be between 0.095 and 0.15 min-1 depending on feed preparation and leaching parameters. The mathematical relationships between aluminum extraction and time for both batch and continuous, stirred-tank operations were derived and verified experimentally.

Jan 1, 1983

By Richard Rittenhouse

This program was to develop a new base line system for automated continuous room and pillar type mining. The primary requirement estab¬lished for this machine is that the machine be capable of mining and bolting simultaneously. Additionally, this machine was to provide temporary and permanent roof control, have a productive - full - face semi-automatic mining system, leave a clean entry outby the machine, provide maximum operator protection, provide effective dust suppression and provide air scrubbing to restrict respirable dust to permissible levels. The machine has effectively demonstrated the ability to mine and bolt simultaneously. Additional above ground operation, testing, and time studies are recommended to further verify the machines abilities. Design improvements are recommended for future generation AES machines. These relate to marginal design areas such as side loading on vent duct lift cylinders, etc., that will not impair additional testing of the existing machine.

Jan 1, 1983

By Edward M. Kawenski

Float dust deposits in return airways in bituminous coal and lignite mines present a special explosion hazard. Research is in progress at the Bureau of Mines experimental coal mine to evaluate the degree of the hazard and to develop measures for preventing dissemination of dust into the ventilating air current. To determine the extent of this hazard prevailing in operating coal mines, 711 dust samples were collected in 50 mines located in the major coal fields of the United States. The mean quantity of coal and the incombustible content of the dust in the samples were determined. The term "float dust" is used to designate particles smaller than 74 microns in diameter (particles passing a No. 200 sieve) which have settled from the air current. Dust usually found in roadways and in working places is coarser than float dust, and is termed "coarse dust" (particles passing a No. 20 sieve). Variations in amount and incombustible content of coarse dust in a midwestern mine were studied previously.

Jan 1, 1963

By J. A. Kosek

Work has been conducted under Bureau of Mines Contract Number HO 357078 to develop instruments for detecting CO, NO and NO2 in a mine atmosphere, using fuel cell technology. The approach has been to optimize the fuel cell sensor configuration for the specific detection of CO, NO and NO2 in the presence of other mine gases utilizing recent advances in catalyst, electrode and solid polymer electrolyte membrane technology. Para-metric testing has been conducted on three electrode sensor cells to define performance and life characteristics as a function of temperature, feed flow and applied sensor voltage. Extended life testing has been performed on sensor cell configurations exhibiting favorable characteristics. Reliable, efficient gas sampling and electronic control circuitry has been fabricated for use with the sensor cells, and integrated into devices to meet the performance and design specifications for portable, battery-powered, hand held direct indicating gas detectors for use underground. Twenty of the production-type, direct indicating CO detectors have been tested and delivered to the Bureau of Mines under the present contract. Three prototype diffusion head CO monitors have also been delivered for evaluation under the pre-sent contract. The gas sampling pump and related parts have been replaced by a diffusion tube assembly in which CO reaches the sensing electrode surface by diffusion alone. In addition, delivery will be made of ten direct-indicating nitric oxide detectors and ten direct-indicating nitrogen dioxide detectors. These instruments are very similar in design to the direct indicating CO detector.

Jan 1, 1979

This sheet explains your audiogram (hearing test) and gives some basic information about protecting your hearing. Keep it so you can refer to it later. What is an audiogram? • An audiogram is often called a “hearing test,” but there’s no pass or fail • It is a written record of your hearing levels • A series of audiograms can track changes in hearing over time • Your hearing threshold levels (the quietest sounds you can hear) are measured in decibels (dB) at different frequencies from low (500 Hz) to high (8000 Hz) Why should I get audiograms? • To measure your hearing ability • To identify hearing problems • To monitor success at maintaining your hearing • To see if noise exposure is affecting your hearing Do I have normal hearing? Compare your hearing threshold levels to this scale: -10 – 25dB Normal hearing 26 – 40 dB Mild loss 41 – 55 dB Moderate loss 56 – 70 dB Moderate/severe loss 71 – 90 dB Severe loss 91 – 100dB Profound loss [ ]

Jan 1, 2008

By R. V. Ramani

This volume is the first of a four-volume final report on research carried out under a contract from the U.S. Bureau of Mines on the development of a computer simulation model for surface mine reclamation planning. The other volumes are titled as follows: Volume II: Dragline Model, Volume III: Mine Coordinate Generator System, and Volume IV: User's Manual for OPMHS/2. This report deals with the development of a geological model for surface mine planning. The most common orebody modeling techniques are described. A brief review of geostatistical theory and concepts is presented. A geostatistical option for orebody modeling is developed and validated. Computer programs and sample outputs are appended.

Jan 1, 1985

The above referenced contract between Badger Manufacturing Corporation and the U. S Bureau of Mines was executed June 30, 1975, as a result of the request for proposals for innovative machine concepts. We selected the cutting machine category because of the obvious lack of technical progress in this field for many years: Phase I of the contract required blasting fragmentation tests to determine proper blasting patterns for use with the auger-type kerf cutting machine. Phase II required design concept development for a machine capable of cutting a circular void as an aid to blasting.

Jan 1, 1975

By Eric E. Unger

Results are presented of a census of the machines used in surface coal mines in the United States. The numbers of each machine type and model reported to be in use are tabulated for large and small mines in the Eastern, Central, and Western regions. Also tabulated are the average daily usage times of the major machine categories and the numbers of machines that have acoustical and other cabs. Projections of the total numbers of primary production machines are given. It is found that heavy tracked dozers and wheeled front end loaders constitute the most prevalent machine types, and that generally a very few models of machines made by one or two manufacturers constitute a major fraction of the population in each machine category. About 70 percent of all machines are reported to have some kind of cab, and about half of these are reported to be acoustical gabs; it is noted that acoustical cabs generally came into significant use since about the early 1970's. It is observed that the percentage-wise mixes of equipment types used in the various categories of mines differ significantly for only a few types of machines, notably for heavy dozers and loaders, and for haulers, highway trucks, and internal-combustion engine-powered shovels and draglines.

Jan 1, 1977

Objective To develop safety training tools for mine health and safety trainers that fill gaps in currently available materials and help capture the wisdom and knowledge of “expert miners.” Background NIOSH began a series of stakeholder meetings in 1998 to determine what research was needed to improve miner health and safety. One of the more common concerns among stakeholders was a critical lack of appropriate training materials applicable to metal/nonmetal mining. Participants provided many insights into what effective training materials should include and how materials could best reach both new and experienced miners. The most important factors were that any materials be realistic and interesting and that some way must be found to capture the wisdom of expert miners before they retired. Approach NIOSH researchers chose videos as the best means of achieving these training goals. Over the past 3 years, NIOSH has produced three training videos that present information on safe work practices in underground mines: handling explosives, recognizing roof hazards and using proper scaling techniques, and installing ground supports. The last two videos, “Rock Falls—Preventing Rock Fall Injuries in Underground Mines” and “Miner Mike Saves the Day—or—Ground Support…It’s Important,” have won Alice Hamilton awards, NIOSH’s highest recognition of Excellence in Occupational Safety and Health, in the Educational Materials category. Two new videos are now being released. Both of these videos were shot completely in operating underground hard-rock mines and used expert miners to tell the story. Hazards In Motion The first, “Hazards in Motion,” deals with the dangers of working around mobile equipment in an underground mine. Ben, a new trainee, refuses to pay attention in his 40-hour New Miner Training class, and when the class takes its first trip underground, he wanders off and finds himself in many dangerous situations. He encounters many experienced miners who both chew him out for his unsafe attitude and give him advice and information on how to survive around mobile equipment. Many common pieces of equipment are shown, including haulage trucks, LHD=s, tracks and trains, slushers, skips and hoists, and air doors. The dangers of ignoring signals and of horseplay are also included. After nearly losing his life numerous times, Ben learns his lesson with the help of the Safety Angel, an experienced miner who looks suspiciously like his safety trainer. Ben’s Safety Angel saves his life repeatedly, teaches him how to work safely around these common conveyances, and introduces him to experts who have specific safety tips. Ben learns the error of his ways and vows to be the safest miner in the mine. “Hazards in Motion” is approximately 30 minutes long. Hidden Scars The second video is the first in the NIOSH “Expert Miner” series. “Hidden Scars” is a narrative interview with Don Capparelli, a miner and supervisor at the Sunshine Mine in north Idaho. This video captures the story of a fatal rock burst in May 1994, when Don was seriously injured and his long-time partner, Jimmy Findley, was killed. “Hidden Scars” is a very powerful story. Don Capparelli shares the physical and emotional pain he lives with daily as he relates the events leading up to the rock burst that took the life of his best friend and partner. This video is an excellent reminder of the human cost of uncontrolled accidents and the hidden scars that survivors must deal with for the rest of their lives. It runs approximately 25 minutes.

Jun 1, 2001

By George K. Clement

Manual estimating method through use of equations, factors and curves for preparation of feasibility type estimates for capital and operating cost of mining and primary beneficiation in the United States and Canada of various types of minerals occurrences, except fossil fuels, using state-of-the-art technology. User should have basic estimating experience in the mining industry and/or related fields. Primary usage of this handbook will be for the preparation of preliminary estimate within a reasonable degree of accuracy with relative small amounts of hard input data. Output may be used to determine if a more finite type of estimate should be produced.

Jan 1, 1978

By E. R. Palowitch

Two samples of the Lower Hartshorne (Spadra) bed were collected: A sample of the raw coal with the machine cuttings excluded, and a sample of the machine cuttings exclusively. Analysis of the 5-inch by 200-mesh size fraction of the raw coal, excluding machine cuttings, showed that a product meeting minimum quality specifications could be produced by washing at 1.60 specific gravity, yielding a theoretical 93.7 percent of clean coal. A negligible amount of near-gravity material at the separation gravity indicated an easy washing problem. The sample of machine cuttings had a maximum size of 2 inches and contained about 50 percent ash. Washability tests of the 2-inch by 200-mesh size fraction indicated that a theoretical yield of 30.0 percent of specification-grade coal could be achieved by washing at 1.49 specific gravity. As the machine cuttings represent an estimated 10 percent of the total coal mined, their inclusion in the mine output would increase the theoretical net yield of salable coal by only 3.7 percent. Because the machine cuttings contained a high percentage of sink 1.80 specific-gravity material, they had neither an effect on the separating gravity required to clean the raw coal nor on the difficulty of separation. Gabbing underground versus transporting the cut-tings to the surface for disposal or washing either separately or combined with the raw coal involves a number of practical, economic; and intangible factors; hence, no specific recommendations could be made. A discussion of some of the factors involved in dealing with a similar problem is given by Gandrud and Riley.4

Jan 1, 1962

By Mandius C. Lundal

This report describes the work done to develop a coal mining machine to increase productivity and recovery from thin seams beyond the highwall, in addition to decreasing the miner's susceptibility to to highwall hazards. First, radar transducers were adapted to measure coal thinkness and detect rock and coal interfaces; Then, the radar was incorporated into a cutterhead with steering controls. Next, visual displays were designed to show cutter position in the coal seam, and anticipated change In coal seam inclination. Finally, development of a telemetry system made remote control of the cutterhead possible. Simultaneously, a high-performance extended depth (HPxD) auger machine was designed with an automatic system to handle 600 ft of 36-in. diameter dual spiral flight conveyor sections. A two man crew controls all operations from a weather conditioned cab outside the VDZ, either at night or day time. As a primary mining tool, working 4000 hr/yr (2 shifts/day) recovering 60% of the coal 600 ft beyond the highwall, production to 500,000 ton/yr can be achieved. Volume II contains technical discussion of subsystems and machine drawings.

Jan 1, 1977

By Stephen A. Swan

This Bureau of Mines report discusses research to analyze and evaluate extended bumper systems in order to determine the degree of protection provided to equipment operators in the event of rear-end collisions be-tween off-road rear-dump haulage trucks. The basic characteristics of rear-end collisions were determined, and a detailed analysis of the col-lision dynamics was performed to identify the magnitude and direction of impact loads, the amount of energy that must be absorbed during impact, and the major factors that affect the outcome of a collision. Separate bumper designs were developed to facilitate attachment to four 170-st-capacity haulage truck frame types.

Jan 1, 1987

By L. D. Johnson

On a project which is to develop a system to suppress coal dust explosions, a facility has been built and several devices tested. The facility is a 317-foot, 4.5-foot diameter shock tube and to date 53 tests have been carried out with methane-air and methane/coal dust-air as the explosive mixtures. Suppression of slowly propagating (up to 300 ft/sec) flame fronts has been successfully carried out on two tests using the dry chemical extinguishing agent Purple K. Delivery of the material directly into the flame front Seems to be required if effective suppression is to be accomplished.

Jan 1, 1972

By K. J. Bathe

The current version of the computer program ADINA/BM (Automatic Dynamic Incremental Nonlinear Analysis for the Bureau of Mines) for linear and nonlinear, static and dynamic finite element analysis of mine structures is described. The complete report is divided into four parts. In Part A the program solution capabilities, the finite element library, the logical construction of the program and storage allocations are discussed. In Part B the theory and numerical techniques used in the program are summarized. In Part C brief problem descriptions and solution results for some sample solutions that have been transmitted as data cases with the program are presented. In the last section of the report, Part D, the users? manual of the program is presented. Program ADINA/BM is a general effective tool for coal mine structural analysis. The program is an extension of the computer program NON SAP (which was developed under an earlier contract with the U.S. Bureau of Mines). The important additional capabilities of ADINA/BM are: (1) the occurrence of all elements is time dependent, (2) all elements can be used in geometric and material nonlinear analysis, (3) the truss element can be used in elastic-plastic analysis, (4) the three-dimensional element can be employed in orthotropic, elastic-plastic and cracking and crushing analysis, (5) the program executes an out-of-core solution and thus allows the analysis of very large and complex coal mine models, (6) the truss elements can be employed as 2-4 variable-number-nodes elements, (7) a rock material model has been implemented, (8) displacement constraint equations can be imposed in the solution, (9) more flexibility in specifying the incremental solution strategy and an acceleration procedure in the equilibrium iteration are available

Jan 1, 1978

By Bruce I. Thomas

Reconnaissance studies of beach sands along the eastern part of the Gulf of Alaska were conducted by the Bureau of Mines to determine if any of these coastal areas warranted investigations as possible sources of valuable minerals. Because of difficult access and limited transportation facilities only a minimum of sampling, surveying, and camping equipment is utilized to obtain spot samples from key areas as well as information indicating the location, size, and character of the deposits. Such data were obtained from beaches located along approximately 247 miles of the Gulf of Alaska coastline during parts of the 1957 and 1958 field seasons. A total of 201 3-inch-diameter auger holes, spaced roughly at 1 mile intervals, were bored by hand methods to depths ranging from 3 feet to 27 feet; also 33 shovel samples were collected from selected localities. Samples were reduced to a rough concentrate in the field by panning; the rough concentrates were shipped to the Bureau of Mines laboratory at Juneau for further concentration and for petrographic and chemical analyses. Particular attention was given to the heavy-mineral content of the concentrates, although the types and relative amounts of rock-forming minerals were also determined. The reconnaissance indicated that, generally, the valuable mineral content of the beach deposits was too low to be of further interest except in the vicinity of Yakutat and Lituya Bays where erratic but possibly significant concentrations of magnetite and/or ilmenite were found. At Yakutat, about 20 miles of beachline extending southeasterly from Ocean Cape, yielded samplas containing from 1 pound to over 300 pounds of iron and from a trace to over 100 pounds of titanium dioxide (TiO2) per cubic yard of beach material. However, the higher grade samples represented local concentrations of minor importance. The general tenor of the Yakutat beach, as indicated by the airthmetical average of 27 auger-hole samples, is about 35 pounds of iron and 20.5 pounds of titanium dioxide per cubic yard of beach material. Ilmenite is the predominant heavy mineral of the beach deposits in the vicinity of Lituya Bay, but it was found in concentrations only in limited areas near the

Jan 1, 1962

By Edward L. McHugh

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 5-acre Zwagg Island Wilderness Study Area (OR-12-14) in order to evaluate its identified mineral resources. The study area is located in Curry County, OR, immediately west of Brookings. There is no evidence of mining activity on or near Zwagg Island, and no mineral resources were identified. The steep-sided, flat-topped island is normally accessible from the mainland by way of a sandy beach. The island consists mainly of marine sandstone, mudstone, and conglomerate of the Jurassic Dothan Formation. Dothan Formation sandstone has been used locally as construction material. Rock along the coast has also been used for construction of jetties to improve harbor access; additional work has been proposed at the port of Brookings. Although suitable for other construction uses, stone from Zwagg Island would probably not meet physical requirements for jetty stone. Development of a stone resource on the island is unlikely.

Jan 1, 1987

By Nathan Feldstein

The wetting of coal dust by aqueous solutions of surface active agents (surfactants) has been studied. Selected for study were thirty coals and typical surfactants selected from the typical classes of anionic, non ionic and cationics. Of these three classes the practical use of cationics in aqueous solutions has been eliminated due to the inherent negative Zeta potential charge of the representative coals studied. The wetting of the coals has been examined by column flow, contact angle, and settling rate measurements. Results indicated that both anionic and nonionic surfactants are to be considered viable for use; low critical micelle concentration values are also preferred for the surfactants. Study of native waters showed substantial variation in properties, i.e., pH, calcium ion concentration, and conductance. pH variations were also noted to affect the effectiveness of selected surfactants. Combinations of nonionic and anionic surfactants have, in certain instances, produced synergistic enhancement in the coal wetting superior to the effectiveness of each surfactant alone.

Jan 1, 1981

By Stephen Gerard Sawyer

This report presents a Fortran IV computer program for the structural analysis of space-frame protective canopies used in underground mines to protect equipment operators from falls of roof, face, or rib. This program entitled CANOPY permits rapid calculation of the elastic strength of a canopy for a variety of static loading conditions. Stresses in, and displacements of each structural member are computed and printed out. Additionally, identification of all members that have commenced yielding, weight of the canopy, total loads on the canopy, and maximum loads that the canopy can sustain elastically are output. Program description, input instructions, program listing, and two example problems are included.

Jan 1, 1972

By S. J. Rodgers

This report presents the results of in-mine studies to determine the severity of dust sources in conventional mining operations. Three underground coal mines were surveyed using gravimetric samplers and GCA RAM-1 continuous dust monitors. Two additional mines were surveyed using only GCA RAM-1 monitors. Data on dust control methods were acquired during the survey, also. The results indicated that cutting/drilling and loading out were the dustiest operations during a conventional mining cycle. Roof bolting, shot firing and product transport were less severe dust sources.

Jan 1, 1983